Comparison of male and female life expectancy at birth for countries and territories as defined in the 2011 CIA Factbook,
with selected bubbles labelled. The green dotted line corresponds to
equal female and male life expectancy. The apparent 3D volumes of the
bubbles are linearly proportional to their population
The word "longevity" is sometimes used as a synonym for "life expectancy" in demography. However, the term longevity is sometimes meant to refer only to especially long-lived members of a population, whereas life expectancy
is always defined statistically as the average number of years
remaining at a given age. For example, a population's life expectancy at
birth is the same as the average age at death for all people born in
the same year (in the case of cohorts).
Longevity is best thought of as a term for general audiences meaning
'typical length of life' and specific statistical definitions should be
clarified when necessary.
Reflections on longevity have usually gone beyond acknowledging
the brevity of human life and have included thinking about methods to
extend life. Longevity has been a topic not only for the scientific
community but also for writers of travel, science fiction, and utopian novels.
There are many difficulties in authenticating the longest human life span
ever by modern verification standards, owing to inaccurate or
incomplete birth statistics. Fiction, legend, and folklore have proposed
or claimed life spans in the past or future vastly longer than those
verified by modern standards, and longevity narratives and unverified longevity claims frequently speak of their existence in the present.
Various factors contribute to an individual's longevity. Significant factors in life expectancy include gender, genetics, access to health care, hygiene, diet and nutrition, exercise, lifestyle, and crime rates. Below is a list of life expectancies in different types of countries:
Eilif Philipsen (1682–1785, 102 years, 333 days): first person
to reach the ages of 100, 101, and 102 (on July 21, 1782) and whose age
could be validated.
Geert Adriaans Boomgaard (1788–1899, 110 years, 135 days): first person to reach the age of 110 (on September 21, 1898) and whose age could be validated
Margaret Ann Neve, (18 May 1792 – 4 April 1903, 110 years, 346 days) the first validated female supercentenarian (on 18 May 1902)
Jeanne Calment
(1875–1997, 122 years, 164 days): the oldest person in history whose
age has been verified by modern documentation. This defines the modern
human life span, which is set by the oldest documented individual who ever lived.
Sarah Knauss (1880–1999, 119 years, 97 days): the second oldest documented person in modern times and the oldest American.
Jiroemon Kimura (1897–2013, 116 years, 54 days): the oldest man in history whose age has been verified by modern documentation.
Evidence-based studies indicate that longevity is based on two major factors, genetics and lifestyle choices.
Genetics
Twin
studies have estimated that approximately 20-30% the variation in human
lifespan can be related to genetics, with the rest due to individual
behaviors and environmental factors which can be modified.
Although over 200 gene variants have been associated with longevity
according to a US-Belgian-UK research database of human genetic
variants, these explain only a small fraction of the heritability.
A 2012 study found that even modest amounts of leisure time physical
exercise can extend life expectancy by as much as 4.5 years.
Lymphoblastoid cell lines established from blood samples of centenarians have significantly higher activity of the DNA repair protein PARP (Poly ADP ribose polymerase) than cell lines from younger (20 to 70 year old) individuals.
The lymphocytic cells of centenarians have characteristics typical of
cells from young people, both in their capability of priming the
mechanism of repair after H2O2 sublethal oxidative DNA damage and in their PARP gene expression. These findings suggest that elevated PARP gene expression contributes to the longevity of centenarians, consistent with the DNA damage theory of aging.
Change over time
In
preindustrial times, deaths at young and middle age were more common
than they are today. This is not due to genetics, but because of
environmental factors such as disease, accidents, and malnutrition,
especially since the former were not generally treatable with pre-20th
century medicine. Deaths from childbirth were common for women, and many
children did not live past infancy. In addition, most people who did
attain old age were likely to die quickly from the above-mentioned
untreatable health problems. Despite this, we do find many examples of
pre-20th century individuals attaining lifespans of 85 years or greater,
including Benjamin Franklin, Thomas Jefferson, John Adams, Cato the Elder, Thomas Hobbes, Eric of Pomerania, Christopher Polhem, and Michelangelo. This was also true for poorer people like peasants or laborers. Genealogists will almost certainly find ancestors living to their 70s, 80s and even 90s several hundred years ago.
For example, an 1871 census in the UK (the first of its kind, but
personal data from other censuses dates back to 1841 and numerical data
back to 1801) found the average male life expectancy as being 44, but
if infant mortality is subtracted, males who lived to adulthood averaged
75 years. The present life expectancy in the UK is 77 years for males
and 81 for females, while the United States averages 74 for males and 80
for females.
Studies have shown that black American males have the shortest
lifespans of any group of people in the US, averaging only 69 years
(Asian-American females average the longest).
This reflects overall poorer health and greater prevalence of heart
disease, obesity, diabetes, and cancer among black American men.
The normal duration of life was estimated to be 65-67 years in
ancient times, 68-71 years in the Middle Ages, and 72-74 years in the
first half of the 19th century.
Women normally outlive men. Theories for this include smaller
bodies (and thus less stress on the heart), a stronger immune system
(since testosterone acts as an immunosuppressant), and less tendency to
engage in physically dangerous activities.
There is debate as to whether the pursuit of longevity is a worthwhile health care goal. Bioethicist Ezekiel Emanuel, who is also one of the architects of ObamaCare, has argued that the pursuit of longevity via the compression of morbidity explanation is a "fantasy" and that longevity past age 75 should not be considered an end in itself. This has been challenged by neurosurgeon Miguel Faria,
who states that life can be worthwhile in healthy old age, that the
compression of morbidity is a real phenomenon, and that longevity should
be pursued in association with quality of life. Faria has discussed how longevity in association with leading healthy lifestyles can lead to the postponement of senescence as well as happiness and wisdom in old age.
Limited longevity
All
of the biological organisms have a limited longevity, and different
species of animals and plants have different potentials of longevity.
Misrepair-accumulation aging theory suggests that the potential of longevity of an organism is related to its structural complexity.
Limited longevity is due to the limited structural complexity of the
organism. If a species of organisms has too high structural complexity,
most of its individuals would die before the reproduction age, and the
species could not survive. This theory suggests that limited structural
complexity and limited longevity are essential for the survival of a
species.
Longevity myths
Longevity myths are traditions about long-lived people (generally supercentenarians),
either as individuals or groups of people, and practices that have been
believed to confer longevity, but for which scientific evidence does
not support the ages claimed or the reasons for the claims. A comparison and contrast of "longevity in antiquity" (such as the Sumerian King List, the genealogies of Genesis, and the Persian Shahnameh) with "longevity in historical times" (common-era cases through twentieth-century news reports) is elaborated in detail in Lucian Boia's 2004 book Forever Young: A Cultural History of Longevity from Antiquity to the Present and other sources.
After the death of Juan Ponce de León, Gonzalo Fernández de Oviedo y Valdés wrote in Historia General y Natural de las Indias (1535) that Ponce de León was looking for the waters of Bimini to cure his aging. Traditions that have been believed to confer greater human longevity also include alchemy, such as that attributed to Nicolas Flamel. In the modern era, the Okinawa diet has some reputation of linkage to exceptionally high ages.
Longevity claims
may be subcategorized into four groups: "In late life, very old people
often tend to advance their ages at the rate of about 17 years per
decade .... Several celebrated super-centenarians (over 110 years) are
believed to have been double lives (father and son, relations with the
same names or successive bearers of a title) .... A number of instances
have been commercially sponsored, while a fourth category of recent
claims are those made for political ends ...." The estimate of 17 years per decade was corroborated by the 1901 and 1911 British censuses. Time magazine considered that, by the Soviet Union, longevity had been elevated to a state-supported "Methuselah cult". Robert Ripley regularly reported supercentenarian claims in Ripley's Believe It or Not!, usually citing his own reputation as a fact-checker to claim reliability.
Future
The U.S. Census Bureau view on the future of longevity is that life expectancy in the United States
will be in the mid-80s by 2050 (up from 77.85 in 2006) and will top out
eventually in the low 90s, barring major scientific advances that can
change the rate of human aging itself, as opposed to merely treating the
effects of aging as is done today. The Census Bureau also predicted
that the United States would have 5.3 million people aged over 100 in
2100. The United Nations
has also made projections far out into the future, up to 2300, at which
point it projects that life expectancies in most developed countries
will be between 100 and 106 years and still rising, though more and more
slowly than before. These projections also suggest that life
expectancies in poor countries will still be less than those in rich
countries in 2300, in some cases by as much as 20 years. The UN itself
mentioned that gaps in life expectancy so far in the future may well not
exist, especially since the exchange of technology between rich and
poor countries and the industrialization
and development of poor countries may cause their life expectancies to
converge fully with those of rich countries long before that point,
similarly to the way life expectancies between rich and poor countries
have already been converging over the last 60 years as better medicine,
technology, and living conditions became accessible to many people in
poor countries. The UN has warned that these projections are uncertain,
and cautions that any change or advancement in medical technology could
invalidate such projections.
Recent increases in the rates of lifestyle diseases, such as obesity, diabetes, hypertension, and heart disease,
may eventually slow or reverse this trend toward increasing life
expectancy in the developed world, but have not yet done so. The average
age of the US population is getting higher and these diseases show up in older people.
Jennifer Couzin-Frankel examined how much mortality from various
causes would have to drop in order to boost life expectancy and
concluded that most of the past increases in life expectancy occurred
because of improved survival rates for young people. She states that it
seems unlikely that life expectancy at birth will ever exceed 85 years. Michio Kaku argues that genetic engineering, nanotechnology and future breakthroughs will accelerate the rate of life expectancy increase indefinitely.
Already genetic engineering has allowed the life expectancy of certain
primates to be doubled, and for human skin cells in labs to divide and
live indefinitely without becoming cancerous.
However, since 1840, record life expectancy has risen linearly
for men and women, albeit more slowly for men. For women the increase
has been almost three months per year, for men almost 2.7 months per
year. In light of steady increase, without any sign of limitation, the
suggestion that life expectancy will top out must be treated with
caution. Scientists Oeppen and Vaupel observe that experts who assert
that "life expectancy is approaching a ceiling ... have repeatedly been
proven wrong." It is thought that life expectancy for women has
increased more dramatically owing to the considerable advances in
medicine related to childbirth.
Non-human biological longevity
Currently living:
A 5,068-year-old member of the species Pinus longaeva: Oldest known currently living tree.
Possibly 250-million year-old bacteria, Bacillus permians,
were revived from stasis after being found in sodium chloride crystals
in a cavern in New Mexico. Russell Vreeland, and colleagues from West Chester University in Pennsylvania, reported on October 18, 2000 that they had revived the halobacteria
after bathing them with a nutrient solution. If they had survived for
250 million years, they would be the oldest living organisms ever
recorded.
However, their findings date the crystal surrounding the bacteria, and
DNA analysis suggests the bacteria themselves are likely to be less
ancient.
The quahog clam (Arctica islandica) is exceptionally long-lived, with a maximum recorded age of 507 years, the longest of any animal. Other clams of the species have been recorded as living up to 374 years.
Lamellibrachia luymesi, a deep-sea cold-seep tubeworm, is estimated to reach ages of over 250 years based on a model of its growth rates.
Hanako was the longest-lived vertebrate ever recorded at 226 years.
A bowhead whale killed in a hunt was found to be approximately 211 years old (possibly up to 245 years old), the longest-lived mammal known.
Certain exotic organisms do not seem to be subject to aging and can live indefinitely. Examples include Tardigrades and Hydras.
That is not to say that these organisms cannot die, merely that they
only die as a result of disease or injury rather than age-related
deterioration (and that they are not subject to the Hayflick limit).
Old age refers to ages nearing or surpassing the life expectancy of human beings, and is thus the end of the human life cycle. Terms and euphemisms include old people, elderly (worldwide usage), seniors (American usage), senior citizens (British and American usages), older adults (in the social sciences), the elderly, and elders (in many cultures—including the cultures of aboriginal people).
Old people often have limited regenerative abilities and are more
susceptible to disease, syndromes, injuries and sickness than younger
adults. The organic process of ageing is called senescence, the medical study of the aging process is called gerontology, and the study of diseases that afflict the elderly is called geriatrics. The elderly also face other social issues around retirement, loneliness, and ageism.
Old age is not a definite biological stage, as the chronological age denoted as "old age" varies culturally and historically.
In 2011, the United Nations proposed a human rights convention that would specifically protect older persons.
Definitions of old age include official definitions, sub-group definitions, and four dimensions as follows.
Official definitions
Old
age comprises "the later part of life; the period of life after youth
and middle age . . ., usually with reference to deterioration".
At what age old age begins cannot be universally defined because it
differs according to the context. The United Nations has agreed that 65+
years may be usually denoted as old age and this is the first attempt at an international definition of old age. However, for its study of old age in Africa, the World Health Organization
(WHO) set 55 as the beginning of old age. At the same time, the WHO
recognized that the developing world often defines old age, not by
years, but by new roles, loss of previous roles, or inability to make
active contributions to society.
Most developed Western countries set the age of 60 to 65 for
retirement. Being 60–65 years old is usually a requirement for becoming
eligible for senior social programs. However, various countries and societies consider the onset of old age as anywhere from the mid-40s to the 70s.
The definitions of old age continue to change especially as life
expectancy in developed countries has risen to beyond 80 years old. In October 2016, a paper published in the science journal Nature presented the conclusion that the maximum human lifespan is an average age of 115, with an absolute upper limit of 125 years.
However, the authors' methods and conclusions drew criticism from the
scientific community, who concluded that the study was flawed.
Sub-group definitions
Gerontologists
have recognized the very different conditions that people experience as
they grow older within the years defined as old age. In developed
countries, most people in their 60s and early 70s are still fit, active,
and able to care for themselves. However, after 75, they will become increasingly frail, a condition marked by serious mental and physical debilitation.
Therefore, rather than lumping together all people who have been
defined as old, some gerontologists have recognized the diversity of old
age by defining sub-groups. One study distinguishes the young old (60
to 69), the middle old (70 to 79), and the very old (80+). Another study's sub-grouping is young-old (65 to 74), middle-old (75–84), and oldest-old (85+). A third sub-grouping is "young old" (65–74), "old" (74–84), and "old-old" (85+). Delineating sub-groups in the 65+ population enables a more accurate portrayal of significant life changes.
Two British scholars, Paul Higgs and Chris Gilleard, have added a
"fourth age" sub-group. In British English, the "third age" is "the
period in life of active retirement, following middle age".
Higgs and Gilleard describe the fourth age as "an arena of inactive,
unhealthy, unproductive, and ultimately unsuccessful ageing".
Dimensions of old age
Key Concepts in Social Gerontology lists four dimensions: chronological, biological, psychological, and social. Wattis and Curran add a fifth dimension: developmental.
Chronological age may differ considerably from a person's functional
age. The distinguishing marks of old age normally occur in all five
senses at different times and different rates for different persons.
In addition to chronological age, people can be considered old because
of the other dimensions of old age. For example, people may be
considered old when they become grandparents or when they begin to do
less or different work in retirement.
Senior citizen
Senior citizen is a common euphemism for an old person used in American English, and sometimes in British English. It implies that the person being referred to is retired. This in turn usually implies that the person is over the retirement age, which varies according to country. Synonyms include old age pensioner or pensioner in British English, and retiree and senior in American English. Some dictionaries describe widespread use of "senior citizen" for people over the age of 65.
When defined in an official context, senior citizen is
often used for legal or policy-related reasons in determining who is
eligible for certain benefits available to the age group.
It is used in general usage instead of traditional terms such as old person, old-age pensioner, or elderly as a courtesy and to signify continuing relevance of and respect for this population group as "citizens" of society, of senior rank.
The term was apparently coined in 1938 during a political campaign. Famed caricaturist Al Hirschfeld claimed on several occasion that his father Isaac Hirschfeld invented the term 'senior citizen'.
It has come into widespread use in recent decades in legislation,
commerce, and common speech. Especially in less formal contexts, it is
often abbreviated as "senior(s)", which is also used as an adjective.
In commerce, some businesses offer customers of a certain age a "senior discount".
The age at which these discounts are available varies between 55, 60,
62 or 65, and other criteria may also apply. Sometimes a special "senior discount card" or other proof of age needs to be obtained and produced to show entitlement.
Age qualifications
The
age which qualifies for senior citizen status varies widely. In
governmental contexts, it is usually associated with an age at which pensions or medical benefits for the elderly become available. In commercial contexts, where it may serve as a marketing device to attract customers, the age is often significantly lower.
In the United States, the standard retirement age is currently 66 (gradually increasing to 67).
In Canada, the OAS (Old Age Security) pension is available at 65
(the Conservative government of Stephen Harper had planned to gradually
increase the age of eligibility to 67, starting in the years 2023–2029,
although the Liberal government of Justin Trudeau is considering leaving
it at 65), and the CPP (Canada Pension Plan) as early as age 60.
The AARP allows couples in which one spouse has reached the age of 50 to join, regardless of the age of the other spouse.
Marks of old age
The distinguishing characteristics of old age are both physical and mental.
The marks of old age are so unlike the marks of middle age that legal
scholar Richard Posner suggests that, as an individual transitions into
old age, he/she can be thought of as different persons "time-sharing"
the same identity.
These marks do not occur at the same chronological age for
everyone. Also, they occur at different rates and order for different
people. Marks of old age can easily vary between people of the same chronological age.
A basic mark of old age that affects both body and mind is "slowness of behavior".
This "slowing down principle" finds a correlation between advancing age
and slowness of reaction and physical and mental task performance.
However, studies from Buffalo University and Northwestern University
have shown that the elderly are a happier age group than their younger
counterparts.
Physical marks of old age
Physical marks of old age include the following:
Bone and joint. Old bones are marked by "thinning and
shrinkage". This might result in a loss of height (about two inches
(5 cm) by age 80), a stooping posture in many people, and a greater
susceptibility to bone and joint diseases such as osteoarthritis and osteoporosis.
Chronic diseases. Some older persons have at least one chronic condition
and many have multiple conditions. In 2007–2009, the most frequently
occurring conditions among older persons in the United States were
uncontrolled hypertension (34%), diagnosed arthritis (50%), and heart disease (32%).
Chronic mucus hypersecretion (CMH) "defined as coughing and bringing up sputum . . . is a common respiratory symptom in elderly persons."
Digestive system. About 40% of the time, old age is marked by
digestive disorders such as difficulty in swallowing, inability to eat
enough and to absorb nutrition, constipation and bleeding.
Essential Tremor (ET) is an uncontrollable shaking in a part of the
upper body. It is more common in the elderly and symptoms worsen with
age.
Eyesight. Presbyopia
can occur by age 50 and it hinders reading especially of small print in
low lighting. Speed with which an individual reads and the ability to
locate objects may also be impaired. By age 80, more than half of all Americans either have a cataract or have had cataract surgery.
Falls. Old age spells risk for injury from falls that might not cause injury to a younger person. Every year, about one-third of those 65 years old and over half of those 80 years old fall. Falls are the leading cause of injury and death for old people.
Gait change. Some aspects of gait
normally change with old age. Gait velocity slows after age 70. Double
stance time (i.e., time with both feet on the ground) also increases
with age. Because of gait change, old people sometimes appear to be
walking on ice.
Hair usually becomes grayer and also might become thinner. As a rule of thumb, around age 50, about 50% of Europeans have 50% grey hair. Many men are affected by balding, and women enter menopause.
Hearing. By age 75 and older, 48% of men and 37% of women encounter
impairments in hearing. Of the 26.7 million people over age 50 with a
hearing impairment, only one in seven uses a hearing aid. In the 70–79 age range, the incidence of partial hearing loss affecting communication rises to 65%, predominantly among low-income males.
Hearts can become less efficient in old age with a resulting loss of
stamina. In addition, atherosclerosis can constrict blood flow.
Immune function. Less efficient immune function (Immunosenescence) is a mark of old age.
Lungs might expand less well; thus, they provide less oxygen.
Mobility impairment or loss. "Impairment in mobility affects 14% of those between 65 and 74, but half of those over 85."
Loss of mobility is common in old people. This inability to get around
has serious "social, psychological, and physical consequences".
Pain afflicts old people at least 25% of the time, increasing with age up to 80% for those in nursing homes. Most pains are rheumatological or malignant.
Sexuality remains important throughout the lifespan and the sexual
expression of "typical, healthy older persons is a relatively neglected
topic of research". Sexual attitudes and identity are established in early adulthood and change minimally over the course of a lifetime.However, sexual drive in both men and women may decrease as they age.
That said, there is a growing body of research on people's sexual
behaviours and desires in later life that challenges the "asexual" image
of older adults. People aged 75–102 continue to experience sensuality
and sexual pleasure. Other known sexual behaviours in older age groups include sexual thoughts, fantasies and erotic dreams, masturbation, oral sex, vaginal and anal intercourse.
Skin loses elasticity, becomes drier, and more lined and wrinkled.
Wounds and injuries take longer to heal.
Wounds and injuries are more likely to leave permanent scars.
Sleep trouble holds a chronic prevalence of over 50% in old age and results in daytime sleepiness. In a study of 9,000 persons with a mean age of 74, only 12% reported no sleep complaints. By age 65, deep sleep goes down to about 5%.
Taste buds diminish so that by age 80 taste buds are down to 50% of normal. Food becomes less appealing and nutrition can suffer.
Over the age of 85, thirst perception decreases, such that 41% of the elderly drink insufficiently.
Urinary incontinence is often found in old age.
Voice. In old age, vocal cords weaken and vibrate more slowly. This
results in a weakened, breathy voice that is sometimes called an "old
person's voice".
Mental marks of old age
Mental marks of old age include the following:
Adaptable describes most people in their old age. Despite the
stressfulness of old age, they are described as "agreeable" and
"accepting". However, old age dependence induces feelings of
incompetence and worthlessness in a minority.
Caution marks old age. This antipathy toward "risk-taking" stems
from the fact that old people have less to gain and more to lose by
taking risks than younger people.
Depressed mood. According to Cox, Abramson, Devine,
and Hollon (2012), old age is a risk factor for depression caused by
prejudice (i.e., "deprejudice"). When people are prejudiced against the
elderly and then become old themselves, their anti-elderly prejudice
turns inward, causing depression. "People with more negative age
stereotypes will likely have higher rates of depression as they get
older." Old age depression results in the over-65 population having the highest suicide rate.
Fear of crime in old age, especially among the frail, sometimes
weighs more heavily than concerns about finances or health and restricts
what they do. The fear persists in spite of the fact that old people
are victims of crime less often than younger people.
Increasing fear of health loss.
Mental disorders afflict about 15% of people aged 60+ according to estimates by the World Health Organization.
Another survey taken in 15 countries reported that mental disorders of
adults interfered with their daily activities more than physical
problems.
Reduced mental and cognitive ability may afflict old age. Memory loss
is common in old age due to the decrease in speed of information being
encoded, stored, and retrieved. It takes more time to learn the same
amount of new information.
Dementia is a general term for memory loss and other intellectual
abilities serious enough to interfere with daily life. Its prevalence
increases in old age from about 10% at age 65 to about 50% over age 85. Alzheimer's disease
accounts for 50 to 80 percent of dementia cases. Demented behavior can
include wandering, physical aggression, verbal outbursts, depression,
and psychosis.
Set in one's ways describes a mind set of old age. A study of over 400 distinguished men and women in old age found a "preference for the routine". Explanations include old age's toll on the "fluid intelligence" and the "more deeply entrenched" ways of the old.
Perceptions of old age
Old age from a middle-age perspective
Many books by middle-age writers depict their perceptions of old people.
One writer notices the change in his parents: they move slowly, they
have lost strength, they repeat stories, their minds wander, and they
fret.
Another writer sees her aged parents and is bewildered: they refuse to
follow her advice, they are obsessed with the past, they avoid risk,
they live at a "glacial pace".
Other writers treat the perceptions of middle-age people regarding their own old age. In her The Denial of Aging, Dr. Muriel R. Gillick, a baby boomer,
accuses her contemporaries of believing that by proper exercise and
diet they can avoid the scourges of old age and proceed from middle age
to death.
Studies find that many people in the 55–75 range can postpone morbidity
by practicing healthy lifestyles. These discourses take part in a
general idea of successful ageing. However, at about age 80, all people experience similar morbidity. Even with healthy lifestyles, most 85+ people will undergo extended "frailty and disability".
Old age from an old-age perspective
Early old age is a pleasant time; children are grown, retirement from work, time to pursue interests. Many people are also willing to get involved in community and activist organizations
to promote their well-being. In contrast, perceptions of old age by
writers 80+ years old (old age in the real meaning of the term) tend to be negative.
Georges Minois (Wikidata)
writes that the first man to talk about his old age was an Egyptian
scribe who lived 4,500 years ago. The scribe addressed God with a prayer
of lament:
O Sovereign my Lord! Oldness has come; old age has
descended. Feebleness has arrived; dotage is here anew. The heart sleeps
wearily every day.
The eyes are weak, the ears are deaf, the
strength is disappearing because of weariness of the heart and the mouth
is silent and cannot speak.
The heart is forgetful and cannot
recall yesterday. The bone suffers old age. Good is become evil. All
taste is gone. What old age does to men is evil in every respect.
Minois comments that the scribe's "cry shows that nothing has changed
in the drama of decrepitude between the age of the Pharaoh and the
atomic age" and "expresses all the anguish of old people in the past and
the present".
Lillian Rubin, active in her 80s as an author, sociologist, and psychotherapist, opens her book 60 on Up: The Truth about Aging in America
with "getting old sucks. It always has, it always will." Dr. Rubin
contrasts the "real old age" with the "rosy pictures" painted by
middle-age writers.
Writing at the age of 87, Mary C. Morrison delineates the heroism
required by old age: to live through the disintegration of one's own
body or that of someone you love. Morrison concludes, "old age is not
for the fainthearted." In the book Life Beyond 85 Years,
the 150 interviewees had to cope with physical and mental debilitation
and with losses of loved ones. One interviewee described living in old
age as "pure hell".
Old age from society's perspective
Based on his survey of old age in history, Georges Minois
concludes that "it is clear that always and everywhere youth has been
preferred to old age." In western thought, "old age is an evil, an
infirmity and a dreary time of preparation for death." Furthermore,
death is often preferred over "decrepitude, because death means
deliverance".
"The problem of the ambiguity of old age has . . . been with us
since the stage of primitive society; it was both the source of wisdom
and of infirmity, experience and decrepitude, of prestige and
suffering."
In the Classical period of Greek and Roman cultures, old age was denigrated as a time of "decline and decrepitude".
"Beauty and strength" were esteemed and old age was viewed as defiling
and ugly. Old age was reckoned as one of the unanswerable "great
mysteries" along with evil, pain, and suffering. "Decrepitude, which
shrivels heroes, seemed worse than death."
The Medieval and Renaissance periods depicted old age as "cruel or weak".
Historical periods reveal a mixed picture of the "position and
status" of old people, but there has never been a "golden age of aging".
Studies have disproved the popular belief that in the past old people
were venerated by society and cared for by their families. Veneration for and antagonism toward the aged have coexisted in complex relationships throughout history. "Old people were respected or despised, honoured or put to death according to circumstance."
In ancient times, although some strong and healthy people lived
until they were over 70 most died before they were 50. The general
understanding is that those who lived into their 40's were treated with
respect and awe. In contrast, those who were frail were seen as a burden
and ignored or in extreme cases killed. People were defined as "old" because of their inability to perform useful tasks rather than their years.
"The Olympians did not like old people." Their youth rebelled against the old, driving them off or killing them.
Although he was skeptical of the gods, Aristotle concurred in the dislike of old people. In his Ethics,
he wrote that "old people are miserly; they do not acknowledge
disinterested friendship; only seeking for what can satisfy their
selfish needs."
The 16th-century Utopians, Thomas More and Antonio de Guevara, allowed no decrepit old people in their fictional lands.
For Thomas More, on the island of Utopia,
when people are so old as to have "out-lived themselves" and are
terminally ill, in pain, and a burden to everyone, the priests exhort
them about choosing to die. The priests assure them that "they shall be
happy after death." If they choose to die, they end their lives by
starvation or by taking opium.
Antonio de Guevara's
utopian nation "had a custom, not to live longer than sixty five
years". At that age, they practiced self-immolation. Rather than condemn
the practice, Bishop Guevara called it a "golden world" in which people
"have overcome the natural appetite to desire to live".
In the Modern period, the "cultural status" of old people has declined in many cultures. Joan Erikson
observed that "aged individuals are often ostracized, neglected, and
overlooked; elders are seen no longer as bearers of wisdom but as
embodiments of shame."
Research on age-related attitudes consistently finds that
negative attitudes exceed positive attitudes toward old people because
of their looks and behavior. In his study Aging and Old Age, Posner discovers "resentment and disdain of older people" in American society.
Harvard University's implicit-association test measures implicit "attitudes and beliefs" about Young vis a vis Old. Blind Spot: Hidden Biases of Good People,
a book about the test, reports that 80% of Americans have an "automatic
preference for the young over old" and that attitude is true worldwide.
The young are "consistent in their negative attitude" toward the old. Ageism
documents that Americans generally have "little tolerance for older
persons and very few reservations about harboring negative attitudes"
about them.
Despite its prevalence, ageism is seldom the subject of public discourse.
In 2014, a documentary film called The Age of Love
used humor and poignant adventures of 30 seniors who attend a speed
dating event for 70- to 90-year-olds, and discovered how the search for
romance changes; or does not change; from a childhood sweetheart to older age.
Old age from simulated perspective
Simone de Beauvoir wrote that "there is one form of experience that belongs only to those that are old – that of old age itself." Nevertheless, simulations of old age attempt to help younger people gain some understanding.
Texas A&M University offers a plan for an "Aging Simulation" workshop. The workshop is adapted from Sensitizing People to the Processes of Aging.
Some of the simulations follow:
Sight: Wearing swimmer's goggles with black paper pasted to lens with only a small hole to simulate tunnel vision,
Hearing: Use ear plugs to dull the sound of people talking.
Touch: Wearing thick gloves, button a shirt or buckle a belt.
Dexterity: With tape around several fingers, unscrew a jar lid.
Mobility and Balance: Carry packages in one hand while using a walker.
The Macklin Intergenerational Institute conducts Xtreme Aging workshops, as depicted in The New York Times. A condensed version was presented on
NBC's Today Show and is available online.
One exercise was to lay out 3 sets of 5 slips of paper. On set #1,
write your 5 most enjoyed activities; on set #2, write your 5 most
valued possessions; on set #3, write your 5 most loved people. Then
"lose" them one by one, trying to feel each loss, until you have lost
them all as happens in old age.
Most people in the age range of 60–80 (the years of retirement and
early old age), enjoy rich possibilities for a full life, but the
condition of frailty distinguished by "bodily failure" and greater dependence becomes increasingly common after that.
In the United States, hospital discharge data from 2003 to 2011 shows
that injury was the most common reason for hospitalization among
patients aged 65+.
Gerontologists
note the lack of research regarding and the difficulty in defining
frailty. However, they add that physicians recognize frailty when they
see it.
A group of geriatricians proposed a general definition of frailty as "a physical state of increased vulnerability to stressors that results from decreased reserves and disregulation in multiple physiological systems".
Prevalence of frailty
Frailty
is a common condition in later old age
but different definitions of frailty produce diverse assessments of
prevalence. One study placed the incidence of frailty for ages 65+ at
10.7%. Another study placed the incidence of frailty in age 65+ population at 22% for women and 15% for men.
A Canadian study illustrated how frailty increases with age and
calculated the prevalence for 65+ as 22.4% and for 85+ as 43.7%.
A worldwide study of "patterns of frailty" based on data from 20
nations found (a) a consistent correlation between frailty and age, (b) a
higher frequency among women, and (c) more frailty in wealthier nations
where greater support and medical care increases longevity.
In Norway, a 20-year longitudinal study of 400 people found that
bodily failure and greater dependence became prevalent in the 80+ years.
The study calls these years the "fourth age" or "old age in the real
meaning of the term". Similarly, the "Berlin Aging Study" rated over-all
functionality on four levels: good, medium, poor, and very poor. People
in their 70s were mostly rated good. In the 80–90 year range, the four
levels of functionality were divided equally. By the 90–100 year range,
60% would be considered frail because of very poor functionality and
only 5% still possessed good functionality.
In the United States, the 85+ age group is the fastest growing, a
group that is almost sure to face the "inevitable decrepitude" of
survivors. (Frailty and decrepitude are synonyms.)
Markers of frailty
Three
unique markers of frailty have been proposed: (a) loss of any notion of
invincibility, (b) loss of ability to do things essential to one's
care, and (c) loss of possibility for a subsequent life stage.
Old age survivors on-average deteriorate from agility in their
65–80s to a period of frailty preceding death. This deterioration is
gradual for some and precipitous for others. Frailty is marked by an
array of chronic
physical and mental problems which means that frailty is not treatable
as a specific disease. These problems coupled with increased dependency
in the basic activities of daily living (ADLs) required for personal care add emotional problems: depression and anxiety.
In sum, frailty has been depicted as a group of "complex issues,"
distinct but "causally interconnected," that often include "comorbid
diseases", progressive weakness, stress, exhaustion, and depression.
Misconceptions of frail people
Johnson and Barer did a pioneering study of Life Beyond 85 Years
by interviews over a six-year period. In talking with 85-year-olds and
older, they found some popular conceptions about old age to be
erroneous. Such erroneous conceptions include (1) people in old age have
at least one family member for support, (2) old age well-being requires
social activity, and (3) "successful adaptation" to age-related changes
demands a continuity of self-concept. In their interviews, Johnson and
Barer found that 24% of the 85+ had no face-to-face family
relationships; many have outlived their families. Second, that contrary
to popular notions, the interviews revealed that the reduced activity
and socializing of the over-85s does not harm their well-being; they
"welcome increased detachment". Third, rather than a continuity of
self-concept, as the interviewees faced new situations they changed
their "cognitive and emotional processes" and reconstituted their
"self–representation".
Care and costs
The hand of an elderly person
Frail people require a high level of care. Medical advances have made
it possible to "postpone death" for years. This added time costs many
frail people "prolonged sickness, dependence, pain, and suffering".
According to a study by the Agency for Healthcare Research and
Quality (AHRQ), the rate of emergency department visits was consistently
highest among patients ages 85 years and older in 2006–2011 in the
United States.
Additionally, patients aged 65+ had the highest percentage of hospital
stays for adults with multiple chronic conditions but the second highest
percentage of hospital costs in 2003–2014.
These final years are also costly in economic terms. One out of every four Medicare dollars is spent on the frail in their last year of life in attempts to postpone death.
Medical treatments in the final days are not only economically costly, they are often unnecessary, even harmful. Nortin Hadler, M.D. warns against the tendency to medicalize and overtreat the frail. In her Choosing Medical Care in Old Age,
Michael R. Gillick M.D. argues that appropriate medical treatment for
the frail is not the same as for the robust. The frail are vulnerable to
"being tipped over" by any physical stress put on the system such as
medical interventions.
Death and frailty
Old
age, death, and frailty are linked because approximately half the
deaths in old age are preceded by months or years of frailty.
Older Adults' Views on Death is based on interviews with
109 people in the 70–90 age range, with a mean age of 80.7.
Almost 20% of the people wanted to use whatever treatment that might
postpone death. About the same number said that, given a terminal
illness, they would choose assisted suicide. Roughly half chose doing
nothing except live day by day until death comes naturally without
medical or other intervention designed to prolong life. This choice was
coupled with a desire to receive palliative care if needed.
About half of older adults suffer multimorbidity, that is, they have three or more chronic conditions. Medical advances have made it possible to "postpone death," but in many
cases this postponement adds "prolonged sickness, dependence, pain, and
suffering," a time that is costly in social, psychological, and
economic terms.
The longitudinal interviews of 150 age 85+ people summarized in Life Beyond 85 Years
found "progressive terminal decline" in the year prior to death:
constant fatigue, much sleep, detachment from people, things, and
activities, simplified lives. Most of the interviewees did not fear
death; some would welcome it. One person said, "Living this long is pure
hell."
However, nearly everyone feared a long process of dying. Some wanted to
die in their sleep; others wanted to die "on their feet".
The study of Older Adults' Views on Death found that the
more frail people were, the more "pain, suffering, and struggles" they
were enduring, the more likely they were to "accept and welcome" death
as a release from their misery. Their fear about the process of dying
was that it would prolong their distress. Besides being a release from
misery, some saw death as a way to reunion with departed loved ones.
Others saw death as a way to free their caretakers from the burden of
their care.
Religiosity in old age
Generally speaking, old people have always been more religious than young people. At the same time, wide cultural variations exist.
In the United States, 90% of old age Hispanics view themselves as very, quite, or somewhat religious. The Pew Research Center's study of black and white old people found
that 62% of those in ages 65–74 and 70% in ages 75+ asserted that
religion was "very important" to them. For all 65+ people, more women
(76%) than men (53%) and more blacks (87%) than whites (63%) consider
religion "very important" to them. This compares to 54% in the 30–49 age
range.
In a British 20-year longitudinal study, less than half of the
old people surveyed said that religion was "very important" to them, and
a quarter said they had become less religious in old age. The late-life rise in religiosity is stronger in Japan than in the United States, but in the Netherlands it is minimal.
In the practice of religion, a study of 60+ people found that 25% read the Bible every day and over 40% look at religious TV. Pew Research found that in the age 65+ range, 75% of whites and 87% of blacks pray daily.
Participation in organized religion is not a good indicator of
religiosity because transportation and health problems often hinder
participation.
Demographic changes
In
the industrialized countries, life expectancy and, thus, the old age
population have increased consistently over the last decades. In the United States the proportion of people aged 65 or older increased from 4% in 1900 to about 12% in 2000. In 1900, only about 3 million
of the nation's citizens were 65 or older (out of 76 million total
American citizens). By 2000, the number of senior citizens had increased
to about 35 million (of 280 million US citizens). Population experts
estimate that more than 50 million Americans—about 17 percent of the population—will be 65 or older in 2020. By 2050, it is projected that at least 400,000 Americans will be 100 or older.
The number of old people is growing around the world chiefly because of the post–World War II baby boom and increases in the provision and standards of health care.
By 2050, 33% of the developed world's population and almost 20% of the
less developed world's population will be over 60 years old.
The growing number of people living to their 80s and 90s in the
developed world has strained public welfare systems and has also
resulted in increased incidence of diseases like cancer and dementia
that were rarely seen in premodern times. When the United States Social
Security program was created, persons older than 65 numbered only around
5% of the population and the average life expectancy of a 65-year-old
in 1936 was approximately 5 years, while in 2011 it could often range
from 10 to 20 years. Other issues that can arise from an increasing
population are growing demands for health care and an increase in demand
for different types of services.
Of the roughly 150,000 people who die each day across the globe, about two thirds—100,000 per day—die of age-related causes. In industrialized nations, the proportion is much higher, reaching 90%.
According to Erik Erikson's "Stages of Psychosocial Development",
the human personality is developed in a series of eight stages that
take place from the time of birth and continue on throughout an
individual's complete life. He characterises old age as a period of
"Integrity vs. Despair", during which a person focuses on reflecting
back on his life. Those who are unsuccessful during this phase will feel
that their life has been wasted and will experience many regrets. The
individual will be left with feelings of bitterness and despair. Those
who feel proud of their accomplishments will feel a sense of integrity.
Successfully completing this phase means looking back with few regrets
and a general feeling of satisfaction. These individuals will attain
wisdom, even when confronting death. Coping is a very important skill needed in the aging process to move
forward with life and not be 'stuck' in the past. The way a person
adapts and copes, reflects his aging process on a psycho-social level.
For people in their 80s and 90s, Joan Erikson added a ninth stage in The Life Cycle Completed: Extended Version.
As she wrote, she added the ninth stage because the Integrity of the
eighth stage imposes "a serious demand on the senses of elders" and the
Wisdom of the eighth stage requires capacities that ninth stage elders
"do not usually have".
Newman & Newman also proposed a ninth stage of life,
Elderhood. Elderhood refers to those individuals who live past the life
expectancy of their birth cohorts. There are two different types of
people described in this stage of life. The "young old" are the healthy
individuals who can function on their own without assistance and can
complete their daily tasks independently. The "old old" are those who
depend on specific services due to declining health or diseases. This
period of life is characterized as a period of "immortality vs.
extinction". Immortality is the belief that your life will go on past
death, some examples are an afterlife or living on through one's family.
Extinction refers to feeling as if life has no purpose.
Social theories, or concepts, propose explanations for the distinctive relationships between old people and their societies.
One of the theories is the disengagement theory
proposed in 1961. This theory proposes that in old age a mutual
disengagement between people and their society occurs in anticipation of
death. By becoming disengaged from work and family responsibilities,
according to this concept, people are enabled to enjoy their old age
without stress.
This theory has been subjected to the criticism that old age
disengagement is neither natural, inevitable, nor beneficial.
Furthermore, disengaging from social ties in old age is not across the
board: unsatisfactory ties are dropped and satisfying ones kept.
In opposition to the disengagement theory, the activity theory
of old age argues that disengagement in old age occurs not by desire,
but by the barriers to social engagement imposed by society. This theory
has been faulted for not factoring in psychological changes that occur
in old age as shown by reduced activity, even when available. It has
also been found that happiness in old age is not proportional to
activity.
According to the continuity theory,
in spite of the inevitable differences imposed by their old age, most
people try to maintain continuity in personhood, activities, and
relationships with their younger days.
Socioemotional selectivity theory
also depicts how people maintain continuity in old age. The focus of
this theory is continuity sustained by social networks, albeit networks
narrowed by choice and by circumstances. The choice is for more
harmonious relationships. The circumstances are loss of relationships by
death and distance.
Life expectancy
Life expectancy by nation at birth in the year 2011 ranged from 48 years to 82. Low values indicate high death rates for infants and children.
In most parts of the world women live, on average, longer than
men; even so, the disparities vary between 12 years in Russia to no
difference or higher life expectancy for men in countries such as
Zimbabwe and Uganda.
The number of elderly persons worldwide began to surge in the
second half of the 20th century. Up to that time (and still true in
underdeveloped countries), five or less percent of the population was
over 65. Few lived longer than their 70s and people who attained
advanced age (i.e. their 80s) were rare enough to be a novelty and were
revered as wise sages. The worldwide over-65 population in 1960 was
one-third of the under 5 population. By 2013, the over-65 population had
grown to equal the under 5 population. The over-65 population is
projected to double the under five by 2050.
Before the surge in the over-65 population, accidents and disease
claimed many people before they could attain old age, and health
problems in those over 65 meant a quick death in most cases. If a person
lived to an advanced age, it was due to genetic factors and/or a
relatively easy lifestyle, since diseases of old age could not be
treated before the 20th century.
In October 2016, scientists identified the maximum human lifespan at an average age of 115, with an absolute upper limit of 125 years. However, the concept of a maximum lifespan in humans is still widely debated among the scientific community.
Old age benefits
German chancellor Otto von Bismarck created the world's first comprehensive government social safety net in the 1880s, providing for old age pensions.
In 2003, the age at which a United States citizen became eligible
for full Social Security benefits began to increase gradually, and will
continue to do so until it reaches 67 in 2027. Full retirement age for
Social Security benefits for people retiring in 2012 is age 66.
In the United Kingdom, the state pension age for men and women will
rise to 66 in 2020 with further increases scheduled after that."
Originally, the purpose of old age pensions was to prevent
elderly persons from being reduced to beggary, which is still common in
some underdeveloped countries, but growing life expectancies and older
populations have brought into question the model under which pension
systems were designed. By 1990, the United States was spending 30 per cent of its budget on the elderly, compared with 2 per cent on education.
The dominant perception of the American old age population changed from
"needy" and "worthy" to "powerful" and "greedy," old people getting
more than their share of the nation's resources. However, in 2011, using a Supplemental Poverty Measure (SPM), the old age American poverty rate was measured as 15.9%.
In the United States in 2008, 11 million people aged 65+ lived alone:
5 million or 22% of ages 65–74, 4 million or 34% of ages 75–84, and 2
million or 41% of ages 85+. The 2007 gender breakdown for all people 65+
was men 19% and women 39%.
Many new assistive devices made especially for the home have enabled more old people to care for themselves activities of daily living (ADL). Able Data lists 40,000 assistive technology products in 20 categories.
Some examples of devices are a medical alert and safety system, shower
seat (making it so the person does not get tired in the shower and
fall), a bed cane (offering support to those with unsteadiness getting
in and out of bed) and an ADL cuff (used with eating utensils for people
with paralysis or hand weakness).
A Swedish study found that at age 76, 46% of the subjects used
assistive devices. When they reached age 86, 69% used them. The subjects
were ambivalent regarding the use of the assistive devices: as
"enablers" or as "disablers".
People who view assistive devices as enabling greater independence
accept and use them. Those who see them as symbols of disability reject
them. However, organizations like Love for the Elderly
aim to combat such age-related prejudice by educating the public about
the importance of appreciating growing older, while also providing
services of kindness to elders in senior homes.
Even with assistive devices as of 2006, 8.5 million Americans needed personal assistance because of impaired basic activities of daily living required for personal care or impaired instrumental activities of daily living
(IADL) required for independent living. Projections place this number
at 21 million by 2030 when 40% of Americans over 70 will need
assistance. There are many options for such long term care to those who require it. There is home care
in which a family member, volunteer, or trained professional will aid
the person in need and help with daily activities. Another option is
community services which can provide the person with transportation,
meal plans, or activities in senior centers. A third option is assisted living where 24-hour round-the-clock supervision is given with aid in eating, bathing, dressing, etc. A final option is a nursing home which provides professional nursing care.
Depictions in art
A scholarly literature has emerged, especially in Britain, showing historical trends in the visual depiction of old age.
Developmental psychology examines the influences of nature and
nurture on the process of human development, and processes of change in
context and across time. Many researchers are interested in the
interactions among personal characteristics, the individual's behavior
and environmental factors, including the social context and the built environment. Ongoing debates include biological essentialism vs. neuroplasticity and stages of development vs. dynamic systems of development.
John B. Watson and Jean-Jacques Rousseau are typically cited as providing the foundations for modern developmental psychology. In the mid-18th century Jean Jacques Rousseau described three stages of development: infants (infancy), puer (childhood) and adolescence in Emile: Or, On Education. Rousseau's ideas were taken up strongly by educators at the time.
It generally focuses on how and why certain modifications
throughout an individual’s life-cycle (cognitive, social, intellectual,
personality) and human growth change over time. There are many theorists
that have made a profound contribution to this area of psychology. For
example, Erik Erikson developed a model of eight stages of psychological
development. He believed that humans developed in stages throughout
their lifetimes and this would affect their behaviors. (Similar ideas to
Sigmund Freud.)
In the late 19th century, psychologists familiar with the evolutionary theory of Darwin began seeking an evolutionary description of psychological development; prominent here was the pioneering psychologist G. Stanley Hall, who attempted to correlate ages of childhood with previous ages of humanity. James Mark Baldwin who wrote essays on topics that included Imitation: A Chapter in the Natural History of Consciousness and Mental Development in the Child and the Race: Methods and Processes. Baldwin was heavily involved in the theory of developmental psychology. Sigmund Freud, whose concepts were developmental, significantly affected public perceptions.
Theories
Psychosexual development
Sigmund Freud
believed that we all had a conscious, preconscious, and unconscious
level. In the conscious, we are aware of our mental process. The
preconscious involves information that, though not currently in our
thoughts, can be brought into consciousness. Lastly, the unconscious
includes mental processes we are unaware of.
He believed there is tension between the conscious and
unconscious because the conscious tries to hold back what the
unconscious tries to express. To explain this he developed three
personality structures: the id, ego, and superego. The id, the most
primitive of the three, functions according to the pleasure principle:
seek pleasure and avoid pain.
The superego plays the critical and moralizing role; and the ego is the
organized, realistic part that mediates between the desires of the id
and the superego.
Based on this, he proposed five universal stages of development,
that each is characterized by the erogenous zone that is the source of
the child's psychosexual energy. The first is the oral stage,
which occurs from birth to 12 months of age. During the oral stage, "the
libido is centered in a baby's mouth." The baby is able to suck. The
second is the anal stage, from one to three years of age. During
the anal stage, the child defecates from the anus and is often
fascinated with their defecation. The third is the phallic stage,
which occurs from three to five years of age (most of a person's
personality forms by this age). During the phallic stage, the child is
aware of their sexual organs. The fourth is the latency stage,
which occurs from age five until puberty. During the latency stage, the
child's sexual interests are repressed. Stage five is the genital stage, which takes place from puberty until adulthood. During the genital stage, puberty starts happening.
Stages of moral development
Piaget claimed that logic and morality develop through constructive stages. Expanding on Piaget's work, Lawrence Kohlberg
determined that the process of moral development was principally
concerned with justice, and that it continued throughout the
individual's lifetime.
He suggested three levels of moral reasoning; pre-conventional
moral reasoning, conventional moral reasoning, and post-conventional
moral reasoning. The pre-conventional moral reasoning is typical of
children and is characterized by reasoning that is based on rewards and
punishments associated with different courses of action. Conventional
moral reason occurs during late childhood and early adolescence and is
characterized by reasoning based on rules and conventions of society.
Lastly, post-conventional moral reasoning is a stage during which the
individual sees society's rules and conventions as relative and
subjective, rather than as authoritative.
Kohlberg used the Heinz Dilemma to apply to his stages of moral
development. The Heinz Dilemma involves Heinz's wife dying from cancer
and Heinz having the dilemma to save his wife by stealing a drug.
Preconventional morality, conventional morality, and post-conventional
morality applies to Heinz's situation.
Stages of psychosocial development
German-American psychologist Erik Erikson and his collaborator and wife, Joan Erikson,
conceptualized eight stages of psychosocial development that they
theorized healthy individuals pass through as they develop from infancy
to adulthood.
The first stage is called "Trust vs. Mistrust" takes place in infancy.
The best virtue for the first stage is hope, in the infant learning who
to trust and having hope for a supportive group of people to be there
for him/her. The second stage is "Autonomy vs. Shame and Doubt" with the
best virtue being will. This takes place in early childhood where the
child learns to become more independent by discovering what they are
capable of where if the child is overly controlled, they believe to feel
inadequate on surviving by themselves, which can lead to low
self-esteem and doubt. The third stage is "Initiative vs. Guilt". The
basic virtue that would be gained is the purpose and takes place in the
play age. This is the stage where the child will be curious and have
many interactions with other kids. They will ask many questions as their
curiosity grows. If too much guilt is present, the child may have a
slower and harder time interacting with other children. The fourth stage
is "Industry (competence) vs. Inferiority". The basic virtue for this
stage is competency which happens at the school age. This stage is when
the child will try to win the approval of others and fit in and
understand the value of their accomplishments. The fifth stage is
"Identity vs. Role Confusion". The basic virtue gained is fidelity which
takes place in adolescence. This is where the child will start to find
who he/she is as a person in society. What sex role he/she picks. The
sixth stage is "Intimacy vs. Isolation", which happens in young adults
and the virtue gained is love. This is where the person will start to
share his/her life with someone else intimately and emotionally. In not
doing so, it could lead to isolation. The seventh stage is "Generativity
vs. Stagnation". This happens in adulthood and the virtue gained would
be care. We become stable and start to give back by raising a family and
becoming involved in the community. The eighth stage is "Ego Integrity
vs. Despair". This happens during maturity and wisdom is gained. When
one grows old and they contemplate and look back and see the success or
failure of their life. This is also the stage where one can also have
closure and accept death without fearing anything.
Theories of cognitive development
Jean Piaget, a Swiss theorist, posited that children learn by actively constructing knowledge through hands-on experience.
He suggested that the adult's role in helping the child learn was to
provide appropriate materials that the child can interact with and use
to construct. He used Socratic questioning to get children to reflect on what they were doing, and he tried to get them to see contradictions in their explanations.
Piaget believed that intellectual development takes place through
a series of stages, which he described in his theory on cognitive
development. Each stage consists of steps the child must master before
moving to the next step. He believed that these stages are not separate
from one another, but rather that each stage builds on the previous one
in a continuous learning process. He proposed four stages: sensorimotor, pre-operational, concrete operational, and formal operational.
Though he did not believe these stages occurred at any given age, many
studies have determined when these cognitive abilities should take
place.
Stages based on the model of hierarchical complexity
Michael Commons
enhanced and simplified of Inhelder and Piaget's developmental and
offers a standard method of examining the universal pattern of
development. The Model of Hierarchical Complexity (MHC) is not based on
the assessment of domain-specific information, It divides the Order of
Hierarchical Complexity of tasks to be addressed from the Stage
performance on those tasks. A stage is the order hierarchical
complexity of the tasks the participant's successfully addresses. He
expanded Piaget's original eight stage (counting the half stages) to
fifteen stages. The stages are : 0 Calculatory; 1 Sensory & Motor; 2
Circular sensory-motor; 3 Sensory-motor; 4 Nominal; 5 Sentential; 6
Preoperational; 7 Primary; 8 Concrete; 9 Abstract; 10 Formal; 11
Systematic; 12 Metasystematic; 13 Paradigmatic; 14 Cross-paradigmatic;
15 Meta-Cross-paradigmatic. The order of hierarchical complexity of
tasks predicts how difficult the performance is with an R ranging from
0.9 to 0.98.
In the MHC, there are three main axioms for an order to meet in
order for the higher order task to coordinate the next lower order task.
Axioms are rules that are followed to determine how the MHC orders
actions to form a hierarchy. These axioms are: a) defined in terms of
tasks at the next lower order of hierarchical complexity task action; b)
defined as the higher order task action that organizes two or more less
complex actions; that is, the more complex action specifies the way in
which the less complex actions combine; c) defined as the lower order
task actions have to be carried out non-arbitrarily.
Ecological systems theory
Bronfenbrenner's ecological systems theory
Ecological systems theory, originally formulated by Urie Bronfenbrenner,
specifies four types of nested environmental systems, with
bi-directional influences within and between the systems. The four
systems are microsystem, mesosystem, exosystem, and macrosystem. Each
system contains roles, norms and rules that can powerfully shape
development. The microsystem is the direct environment in our lives such
as our home and school. Mesosystem is how relationships connect to the
microsystem. Exosystem is a larger social system where the child plays
no role. Macrosystem refers to the cultural values, customs and laws of
society.
The microsystem is the immediate environment surrounding and
influencing the individual (example: school or the home setting). The
mesosystem is the combination of two microsystems and how they influence
each other (example: sibling relationships at home vs. peer
relationships at school). The exosystem is the interaction among two or
more settings that are indirectly linked (example: a father's job
requiring more overtime ends up influencing his daughter's performance
in school because he can no longer help with her homework). The
macrosystem is broader taking into account social economic status,
culture, beliefs, customs and morals (example: a child from a wealthier
family sees a peer from a less wealthy family as inferior for that
reason). Lastly, the chronosystem refers to the chronological nature of
life events and how they interact and change the individual and their
circumstances through transition (example: a mother losing her own
mother to illness and no longer having that support in her life).
Since its publication in 1979, Bronfenbrenner's major statement of this theory, The Ecology of Human Development
has had widespread influence on the way psychologists and others
approach the study of human beings and their environments. As a result
of this conceptualization of development, these environments—from the
family to economic and political structures—have come to be viewed as
part of the life course from childhood through to adulthood.
Zone of proximal development
Lev Vygotsky
was a Russian theorist from the Soviet era, who posited that children
learn through hands-on experience and social interactions with members
of his/her culture.
Unlike Piaget, he claimed that timely and sensitive intervention by
adults when a child is on the edge of learning a new task (called the
"zone of proximal development") could help children learn new tasks.
This adult role is often referred to as the skilled "master," whereas
the child is considered the learning apprentice through an educational
process often termed "cognitive apprenticeship"
Martin Hill stated that "The world of reality does not apply to the
mind of a child." This technique is called "scaffolding," because it
builds upon knowledge children already have with new knowledge that
adults can help the child learn.
Vygotsky was strongly focused on the role of culture in determining the
child's pattern of development, arguing that development moves from the
social level to the individual level.
In other words, Vygotsky claimed that psychology should focus on the
progress of human consciousness through the relationship of an
individual and their environment.
He felt that if scholars continued to disregard this connection, then
this disregard would inhibit the full comprehension of the human
consciousness.
Constructivism
Constructivism is a paradigm in psychology that characterizes
learning as a process of actively constructing knowledge. Individuals
create meaning for themselves or make sense of new information by
selecting, organizing, and integrating information with other knowledge,
often in the context of social interactions. Constructivism can occur
in two ways: individual and social. Individual constructivism is when a
person constructs knowledge through cognitive processes of their own
experiences rather than by memorizing facts provided by others. Social
constructivism is when individuals construct knowledge through an
interaction between the knowledge they bring to a situation and social
or cultural exchanges within that content.
Jean Piaget, a Swiss developmental psychologist, proposed that
learning is an active process because children learn through experience
and make mistakes and solve problems. Piaget proposed that learning
should be whole by helping students understand that meaning is
constructed.
Evolutionary developmental psychology
Evolutionary developmental psychology is a research paradigm that applies the basic principles of Darwinian evolution, particularly natural selection, to understand the development of human behavior and cognition. It involves the study of both the genetic and environmental mechanisms that underlie the development of social and cognitive competencies, as well as the epigenetic (gene-environment interactions) processes that adapt these competencies to local conditions.
EDP considers both the reliably developing, species-typical features of ontogeny (developmental adaptations), as well as individual differences
in behavior, from an evolutionary perspective. While evolutionary views
tend to regard most individual differences as the result of either
random genetic noise (evolutionary byproducts) and/or idiosyncrasies (for example, peer groups, education, neighborhoods, and chance encounters)
rather than products of natural selection, EDP asserts that natural
selection can favor the emergence of individual differences via
"adaptive developmental plasticity."
From this perspective, human development follows alternative
life-history strategies in response to environmental variability, rather
than following one species-typical pattern of development.
EDP is closely linked to the theoretical framework of evolutionary psychology
(EP), but is also distinct from EP in several domains, including
research emphasis (EDP focuses on adaptations of ontogeny, as opposed to
adaptations of adulthood) and consideration of proximate ontogenetic
and environmental factors (i.e., how development happens) in addition to
more ultimate factors (i.e., why development happens), which are the
focus of mainstream evolutionary psychology.
Attachment theory
Attachment theory, originally developed by John Bowlby, focuses on the importance of open, intimate, emotionally meaningful relationships.
Attachment is described as a biological system or powerful survival
impulse that evolved to ensure the survival of the infant. A child who
is threatened or stressed will move toward caregivers who create a sense
of physical, emotional and psychological safety for the individual.
Attachment feeds on body contact and familiarity. Later Mary Ainsworth developed the Strange Situation protocol and the concept of the secure base.
Theorists have proposed four types of attachment styles: secure, anxious-avoidant, anxious-resistant, and disorganized.
Secure attachment is a healthy attachment between the infant and the
caregiver. It is characterized by trust. Anxious-avoidant is an insecure
attachment between an infant and a caregiver. This is characterized by
the infant's indifference toward the caregiver. Anxious-resistant is an
insecure attachment between the infant and the caregiver characterized
by distress from the infant when separated and anger when reunited. Disorganized is an attachment style without a consistent pattern of responses upon return of the parent.
A child can be hindered in its natural tendency to form
attachments. Some babies are raised without the stimulation and
attention of a regular caregiver or locked away under conditions of
abuse or extreme neglect. The possible short-term effects of this
deprivation are anger, despair, detachment, and temporary delay in
intellectual development. Long-term effects include increased
aggression, clinging behavior, detachment, psychosomatic disorders, and
an increased risk of depression as an adult.
Attachment style can affect the relationships between people.
Attachment is established in early childhood and attachment continues
into adulthood. An example of secure attachment continuing in adulthood
would be when the person feels confident and is able to meet their own
needs. An example of anxious attachment during adulthood is when the
adult chooses a partner with anxious-avoidant attachment.
Major debates
Nature vs nurture
A
significant issue in developmental psychology is the relationship
between innateness and environmental influence in regard to any
particular aspect of development. This is often referred to as "nature and nurture" or nativism versus empiricism.
A nativist account of development would argue that the processes in
question are innate, that is, they are specified by the organism's genes.
An empiricist perspective would argue that those processes are
acquired in interaction with the environment. Today developmental
psychologists rarely take such polarised positions with regard to most
aspects of development; rather they investigate, among many other
things, the relationship between innate and environmental influences.
One of the ways this relationship has been explored in recent years is
through the emerging field of evolutionary developmental psychology.
One area where this innateness debate has been prominently portrayed is in research on language acquisition.
A major question in this area is whether or not certain properties of
human language are specified genetically or can be acquired through learning.
The empiricist position on the issue of language acquisition suggests
that the language input provides the necessary information required for
learning the structure of language and that infants acquire language
through a process of statistical learning.
From this perspective, language can be acquired via general learning
methods that also apply to other aspects of development, such as perceptual learning.
The nativist position argues that the input from language is too
impoverished for infants and children to acquire the structure of
language. Linguist Noam Chomsky asserts that, evidenced by the lack of sufficient information in the language input, there is a universal grammar that applies to all human languages and is pre-specified. This has led to the idea that there is a special cognitive module suited for learning language, often called the language acquisition device.
Chomsky's critique of the behaviorist model of language acquisition is
regarded by many as a key turning point in the decline in the prominence
of the theory of behaviorism generally.
But Skinner's conception of "Verbal Behavior" has not died, perhaps in
part because it has generated successful practical applications.
Continuity vs discontinuity
Since
theorists believe that development is a smooth, continuous process,
individuals gradually add more of the same types of skills throughout
their lives. Other theorists, however, think that development takes
place in discontinuous stages. People change rapidly and step up to a
new level, and then change very little for a while. With each new step,
the person shows interest and responds to the world qualitatively.
Stability vs change
This
issue involves the degree to which we become older renditions of our
early experience or whether we develop into something different from who
we were at an earlier point in development. It considers the extent to
which early experiences ( especially infancy) or later experiences are
the key determinants of a person's development.
Most lifespan developmentalists, recognise that extreme positions
are unwise. Therefore, the key to a comprehensive understanding of
development at any stage requires the ·interaction of different factors
and not only one.
Mechanisms of Development
Developmental
psychology is concerned not only with describing the characteristics of
psychological change over time but also seeks to explain the principles
and internal workings underlying these changes. Psychologists have
attempted to better understand these factors by using models. Developmental models are sometimes computational, but they do not need to be.
A model must simply account for the means by which a process takes place. This is sometimes done in reference to changes in the brain
that may correspond to changes in behavior over the course of the
development. Computational accounts of development often use either symbolic, connectionist (neural network), or dynamical systems models to explain the Mechanisms of Development.
Research areas
Cognitive development
Cognitive development is primarily concerned with the ways that
infants and children acquire, develop, and use internal mental
capabilities such as: problem-solving, memory, and language. Major
topics in cognitive development are the study of language acquisition
and the development of perceptual and motor skills. Piaget was one of
the influential early psychologists to study the development of
cognitive abilities. His theory suggests that development proceeds
through a set of stages from infancy to adulthood and that there is an
end point or goal.
Other accounts, such as that of Lev Vygotsky,
have suggested that development does not progress through stages, but
rather that the developmental process that begins at birth and continues
until death is too complex for such structure and finality. Rather,
from this viewpoint, developmental processes proceed more continuously.
Thus, development should be analyzed, instead of treated as a product to
obtain.
K. Warner Schaie
has expanded the study of cognitive development into adulthood. Rather
than being stable from adolescence, Schaie sees adults as progressing
in the application of their cognitive abilities.
Modern cognitive development has integrated the considerations of cognitive psychology and the psychology of individual differences into the interpretation and modeling of development. Specifically, the neo-Piagetian theories of cognitive development showed that the successive levels or stages of cognitive development are associated with increasing processing efficiency and working memory
capacity. These increases explain differences between stages,
progression to higher stages, and individual differences of children who
are the same-age and of the same grade-level. However, other theories
have moved away from Piagetian stage theories, and are influenced by
accounts of domain-specific
information processing, which posit that development is guided by
innate evolutionarily-specified and content-specific information
processing mechanisms.
Social and emotional development
Developmental psychologists who are interested in social development
examine how individuals develop social and emotional competencies. For
example, they study how children form friendships, how they understand
and deal with emotions, and how identity develops. Research in this area
may involve study of the relationship between cognition or cognitive
development and social behavior.
Emotional regulation
or ER refers to an individual's ability to modulate emotional responses
across a variety of contexts. In young children, this modulation is in
part controlled externally, by parents and other authority figures. As
children develop, they take on more and more responsibility for their
internal state. Studies have shown that the development of ER is
affected by the emotional regulation children observe in parents and
caretakers, the emotional climate in the home, and the reaction of
parents and caretakers to the child's emotions.
Music also has an influence on stimulating and enhancing the senses of a child through self-expression.
A child's social and emotional development can be disrupted by
motor coordination problems as evidenced by the environmental stress
hypothesis. The environmental hypothesis explains how children with
coordination problems and developmental coordination disorder are exposed to several psychosocial consequences which act as secondary stressors, leading to an increase in internalizing symptoms such as depression and anxiety.
Motor coordination problems affect fine and gross motor movement as
well as perceptual-motor skills. Secondary stressors commonly
identified include the tendency for children with poor motor skills to
be less likely to participate in organized play with other children and
more likely to feel socially isolated.
Social and emotional development focuses on 5 keys areas:
Self-Awareness, Self Management, Social Awareness, Relationship Skills
and Responsible Decision Making.
Physical development
Physical
development concerns the physical maturation of an individual's body
until it reaches the adult stature. Although physical growth is a highly
regular process, all children differ tremendously in the timing of
their growth spurts.
Studies are being done to analyze how the differences in these timings
affect and are related to other variables of developmental psychology
such as information processing speed. Traditional measures of physical
maturity using x-rays are less in practice nowadays, compared to simple
measurements of body parts such as height, weight, head circumference,
and arm span.
A few other studies and practices with physical developmental
psychology are the phonological abilities of mature 5- to 11-year-olds,
and the controversial hypotheses of left-handers being maturationally
delayed compared to right-handers. A study by Eaton, Chipperfield,
Ritchot, and Kostiuk in 1996 found in three different samples that there
was no difference between right- and left-handers.
Memory development
Researchers interested in memory development look at the way our memory develops from childhood and onward. According to Fuzzy-trace theory,
we have two separate memory processes: verbatim and gist. These two
traces begin to develop at different times as well as at a different
pace. Children as young as 4 years-old have verbatim memory, memory for
surface information, which increases up to early adulthood, at which
point it begins to decline. On the other hand, our capacity for gist
memory, memory for semantic information, increases up to early
adulthood, at which point it is consistent through old age. Furthermore,
our reliance on gist memory traces increases as we age.
Research methods and designs
Main research methods
Developmental psychology employs many of the research methods
used in other areas of psychology. However, infants and children cannot
be tested in the same ways as adults, so different methods are often
used to study their development.
Developmental psychologists have a number of methods to study
changes in individuals over time. Common research methods include
systematic observation, including naturalistic observation or structured observation; self-reports, which could be clinical interviews or structured interviews; clinical or case study method; and ethnography or participant observation.
These methods differ in the extent of control researchers impose on
study conditions, and how they construct ideas about which variables to
study. Every developmental investigation can be characterized in terms of whether its underlying strategy involves the experimental, correlational, or case study approach. The experimental method involves "actual manipulation of various treatments, circumstances, or events to which the participant or subject is exposed; the experimental design points to cause-and-effect relationships. This method allows for strong inferences to be made of causal relationships between the manipulation of one or more independent variables and subsequent behavior, as measured by the dependent variable. The advantage of using this research method is that it permits determination of cause-and-effect relationships among variables. On the other hand, the limitation is that data obtained in an artificial environment may lack generalizability.
The correlational method explores the relationship between two or more
events by gathering information about these variables without researcher
intervention.
The advantage of using a correlational design is that it estimates the
strength and direction of relationships among variables in the natural
environment; however, the limitation is that it does not permit determination of cause-and-effect relationships among variables. The case study approach allows investigations to obtain an in-depth understanding of an individual participant by collecting data based on interviews, structured questionnaires, observations, and test scores.
Each of these methods have its strengths and weaknesses but the
experimental method when appropriate is the preferred method of
developmental scientists because it provides a controlled situation and
conclusions to be drawn about cause-and-effect relationships.
Research designs
Most
developmental studies, regardless of whether they employ the
experimental, correlational, or case study method, can also be
constructed using research designs. Research designs are logical frameworks used to make key comparisons within research studies such as:
In a longitudinal study, a researcher observes many individuals born at or around the same time (a cohort)
and carries out new observations as members of the cohort age. This
method can be used to draw conclusions about which types of development
are universal (or normative)
and occur in most members of a cohort. As an example a longitudinal
study of early literacy development examined in detail the early
literacy experiences of one child in each of 30 families.
Researchers may also observe ways that development varies between
individuals, and hypothesize about the causes of variation in their
data. Longitudinal studies often require large amounts of time and
funding, making them unfeasible in some situations. Also, because
members of a cohort all experience historical events unique to their
generation, apparently normative developmental trends may, in fact, be
universal only to their cohort.
In a cross-sectional study,
a researcher observes differences between individuals of different ages
at the same time. This generally requires fewer resources than the
longitudinal method, and because the individuals come from different
cohorts, shared historical events are not so much of a confounding factor.
By the same token, however, cross-sectional research may not be the
most effective way to study differences between participants, as these
differences may result not from their different ages but from their
exposure to different historical events.
A third study design, the sequential design,
combines both methodologies. Here, a researcher observes members of
different birth cohorts at the same time, and then tracks all
participants over time, charting changes in the groups. While much more
resource-intensive, the format aids in a clearer distinction between
what changes can be attributed to an individual or historical
environment from those that are truly universal.
Because every method has some weaknesses, developmental
psychologists rarely rely on one study or even one method to reach
conclusions by finding consistent evidence from as many converging
sources as possible.
Life stages of psychological development
Prenatal development
Prenatal development is of interest to psychologists investigating
the context of early psychological development. The whole prenatal
development involves three main stages: germinal stage, embryonic stage
and fetal stage. Germinal stage begins at conception until 2 weeks;
embryonic stage means the development from 2 weeks to 8 weeks; fetal
stage represents 9 weeks until birth of the baby.
The senses develop in the womb itself: a fetus can both see and hear by
the second trimester (13 to 24 weeks of age). The sense of touch
develops in the embryonic stage (5 to 8 weeks). Most of the brain's billions of neurons also are developed by the second trimester. Babies are hence born with some odor, taste and sound preferences, largely related to the mother's environment.
Some primitive reflexes
too arise before birth and are still present in newborns. One
hypothesis is that these reflexes are vestigial and have limited use in
early human life. Piaget's theory of cognitive development suggested that some early reflexes are building blocks for infant sensorimotor development. For example, the tonic neck reflex may help development by bringing objects into the infant's field of view.
Other reflexes, such as the walking reflex
appear to be replaced by more sophisticated voluntary control later in
infancy. This may be because the infant gains too much weight after
birth to be strong enough to use the reflex, or because the reflex and
subsequent development are functionally different. It has also been suggested that some reflexes (for example the moro and walking reflexes) are predominantly adaptations to life in the womb with little connection to early infant development. Primitive reflexes reappear in adults under certain conditions, such as neurological conditions like dementia or traumatic lesions.
Ultrasound has shown that infants are capable of a range of movements in the womb, many of which appear to be more than simple reflexes.
By the time they are born, infants can recognize and have a preference
for their mother's voice suggesting some prenatal development of
auditory perception. Prenatal development and birth complications may also be connected to neurodevelopmental disorders, for example in schizophrenia. With the advent of cognitive neuroscience, embryology and the neuroscience of prenatal development is of increasing interest to developmental psychology research.
Several environmental agents—teratogens—can
cause damage during the prenatal period. These include prescription and
nonprescription drugs, illegal drugs, tobacco, alcohol, environmental
pollutants, infectious disease agents such as the rubella virus and the toxoplasmosis parasite, maternal malnutrition, maternal emotional stress, and Rh factor blood incompatibility between mother and child.
There are many statistics which prove the effects of the aforementioned
substances. A leading example of this would be that, in America alone,
approximately 100,000-375,000 'cocaine babies' are born on an annual
basis. This is a result of an expectant mother abusing the drug while
pregnant. 'Cocaine babies' are proven to have quite severe and lasting
difficulties which persist throughout infancy and right throughout
childhood. The drug also encourages behavioural problems in the affected
children, as well as defects of various vital organs.
Infancy
From birth until the first year, the child is referred to as an infant.
Developmental psychologists vary widely in their assessment of infant
psychology, and the influence the outside world has upon it, but certain
aspects are relatively clear.
The majority of a newborn infant's time is spent in sleep. At
first, this sleep is evenly spread throughout the day and night, but
after a couple of months, infants generally become diurnal.
Infants can be seen to have six states, grouped into pairs:
Infant
perception is what a newborn can see, hear, smell, taste, and touch.
These five features are better known as one's "five senses". Infants respond to stimuli differently in these different states.
Vision
is significantly worse in infants than in older children. Infant sight
tends to be blurry in early stages but improves over time. Color
perception similar to that seen in adults has been demonstrated in
infants as young as four months, using habituation methods. Infants get to adult-like vision in about six months.
Hearing
is well-developed prior to birth, unlike vision. Newborns prefer
complex sounds to pure tones, human speech to other sounds, mother's
voice to other voices, and the native language to other languages.
Scientist believe these features are probably learned in the womb.
Infants are fairly good at detecting the direction a sound comes from,
and by 18 months their hearing ability is approximately equal to an
adult's.
Smell and taste
are present, with infants showing different expressions of disgust or
pleasure when presented with pleasant odors (honey, milk, etc.) or
unpleasant odors (rotten egg) and tastes (e.g. sour taste). Newborns are
born with odor and taste preferences acquired in the womb from the
smell and taste of amniotic fluid, in turn influenced by what the mother
eats. Both breast- and bottle-fed babies around 3 days old prefer the
smell of human milk to that of formula, indicating an innate preference. There is good evidence for older infants preferring the smell of their mother to that of others.
Touch and feel is one of the better-developed senses at birth considering it's one of the first senses to develop inside the womb. This is evidenced by the primitive reflexes described above, and the relatively advanced development of the somatosensory cortex.
Pain:
Infants feel pain similarly, if not more strongly than older children
but pain-relief in infants has not received so much attention as an area
of research. Glucose is known to relieve pain in newborns.
Language
Babies are born with the ability to discriminate virtually all sounds of all human languages. Infants of around six months can differentiate between phonemes in their own language, but not between similar phonemes in another language. At this stage infants also start to babble, producing phonemes.
Infant cognition: the Piagetian era
Piaget
suggested that an infant's perception and understanding of the world
depended on their motor development, which was required for the infant
to link visual, tactile and motor representations of objects. According to this view, it is through touching and handling objects that infants develop object permanence, the understanding that objects are solid, permanent, and continue to exist when out of sight.
Special methods are used in the psychological study of infants
Piaget's sensorimotor stage comprised six sub-stages (see sensorimotor stages for more detail). In the early stages, development arises out of movements caused by primitive reflexes. Discovery of new behaviors results from classical and operant conditioning, and the formation of habits. From eight months the infant is able to uncover a hidden object but will persevere when the object is moved.
Piaget came to his conclusion that infants lacked a complete
understanding of object permanence before 18 months after observing
infants' failure before this age to look for an object where it was last
seen. Instead, infants continue to look for an object where it was
first seen, committing the "A-not-B error."
Some researchers have suggested that before the age of eight to nine
months, infants' inability to understand object permanence extends to
people, which explains why infants at this age do not cry when their
mothers are gone ("Out of sight, out of mind").
Recent findings in infant cognition
In
the 1980s and 1990s, researchers have developed many new methods of
assessing infants' understanding of the world with far more precision
and subtlety than Piaget was able to do in his time. Since then, many
studies based on these methods suggest that young infants understand far
more about the world than first thought.
Based on recent findings, some researchers (such as Elizabeth Spelke and Renee Baillargeon)
have proposed that an understanding of object permanence is not learned
at all, but rather comprises part of the innate cognitive capacities of
our species.
Other research has suggested that young infants in their first
six months of life may possess an understanding of numerous aspects of
the world around them, including:
an early numerical cognition, that is, an ability to represent number and even compute the outcomes of addition and subtraction operations;
an ability to infer the goals of people in their environment;
an ability to engage in simple causal reasoning.
Critical periods of development
There are critical periods
in infancy and childhood during which development of certain
perceptual, sensorimotor, social and language systems depends crucially
on environmental stimulation. Feral children such as Genie,
deprived of adequate stimulation, fail to acquire important skills and
are unable to learn in later childhood. The concept of critical periods
is also well-established in neurophysiology, from the work of Hubel and Wiesel among others.
Developmental delays
Children
with developmental delays (DD) are at heightened risk for developing
clinically significant behavioral and emotional difficulties as compared
to children with typical development (TD). However, nearly all studies
comparing psychopathology in youth with DD employ TD control groups of
the same chronological age (CA).This comorbidity of DD and a mental
disorder is often referred to as dual diagnosis. Epidemiological studies
indicate that 30–50% of youth with DD meet the clinical cutoff for
behavioral and emotional problems and/or diagnosable mental disorder.
Studies that include comparison samples of children with typical
development (TD) highlight the considerable difference in risk for
psychopathology, with the relative risk for youth with DD (to youth with
TD) ranging from 2.8–4.1 to 1.
Toddler-hood
Infants shift between ages of one and two to a developmental stage
known as toddlerhood. In this stage, an infant's transition into
toddlerhood is highlighted through self-awareness, developing maturity
in language use, and presence of memory and imagination.
During toddlerhood, babies begin learning how to walk, talk, and make decisions for themselves. An important characteristic of this age period is the development of language,
where children are learning how to communicate and express their
emotions and desires through the use of vocal sounds, babbling, and
eventually words.
Self-control also begins to develop. At this age, children take
initiative to explore, experiment and learn from making mistakes.
Caretakers who encourage toddlers to try new things and test their
limits, help the child become autonomous, self-reliant, and confident. If the caretaker is overprotective or disapproving of independent
actions, the toddler may begin to doubt their abilities and feel ashamed
of the desire for independence. The child's autonomic development is
inhibited, leaving them less prepared to deal with the world in the
future. Toddlers also begin to identify themselves in gender roles, acting according to their perception of what a man or woman should do.
Socially, the period of toddler-hood is commonly called the "terrible twos".
Toddlers often use their new-found language abilities to voice their
desires, but are often misunderstood by parents due to their language
skills just beginning to develop. A person at this stage testing their
independence is another reason behind the stage's infamous label.
Tantrums in a fit of frustration are also common.
Childhood
Erik Erikson divides childhood into four stages, each with its distinct social crisis:
Stage 1: Infancy (0 to 1½) in which the psychosocial crisis is Trust vs. Mistrust
Stage 2: Early childhood (2½ to 3) in which the psychosocial crisis is Autonomy vs. Shame and doubt
Stage 3: Play age (3 to 5) in which the psychosocial crisis is
Initiative vs. Guilt. (This stage is also called the "pre-school age,"
"exploratory age" and "toy age.")
Stage 4: School age (5 to 12) in which the psychosocial crisis is Industry vs. Inferiority
Play (or preschool) ages 3–5.
In the earliest years, children are "completely dependent on the care of
others." Therefore, they develop a "social relationship" with their
care givers and, later, with family members. During their preschool
years (3-5), they "enlarge their social horizons" to include people
outside the family.
Preoperational and then operational thinking develops, which means actions are reversible, and egocentric thought diminishes.
The motor skills of preschoolers increase so they can do more
things for themselves. They become more independent. No longer
completely dependent on the care of others, the world of this age group
expands. More people have a role in shaping their individual
personalities. Preschoolers explore and question their world. For Jean Piaget, the child is "a little scientist exploring and reflecting on these explorations to increase competence" and this is done in "a very independent way."
Play is a major activity for ages 3–5. For Piaget, through play "a child reaches higher levels of cognitive development."
In their expanded world, children in the 3-5 age group attempt to
find their own way. If this is done in a socially acceptable way, the
child develops the initiative. If not, the child develops guilt. Children who develop "guilt" rather than "initiative" have failed Erikson's psychosocial crisis for the 3-5 age group.
Middle childhood ages 6–12.
For Erik Erikson, the psychosocial crisis during middle childhood is
Industry vs. Inferiority which, if successfully met, instills a sense of
Competency in the child.
In all cultures, middle childhood is a time for developing "skills that will be needed in their society."
School offers an arena in which children can gain a view of themselves
as "industrious (and worthy)." They are "graded for their school work
and often for their industry." They can also develop industry outside of
school in sports, games, and doing volunteer work. Children who achieve "success in school or games might develop a feeling of competence."
The "peril during this period is that feelings of inadequacy and inferiority will develop.
Parents and teachers can "undermine" a child's development by failing
to recognize accomplishments or being overly critical of a child's
efforts.
Children who are "encouraged and praised" develop a belief in their
competence. Lack of encouragement or ability to excel lead to "feelings
of inadequacy and inferiority".
The Centers for Disease Control
(the CDC) divides Middle Childhood into two stages, 6–8 years and 9–11
years, and gives "developmental milestones for each stage."
Middle Childhood (7-10).
Entering elementary school, children in this age group begin to thinks
about the future and their "place in the world." Working with other
students and wanting their friendship and acceptance become more
important. This leads to "more independence from parents and family." As
students, they develop the mental and verbal skills "to describe
experiences and talk about thoughts and feelings". They become less
self-centered and show "more concern for others".
Middle Childhood (9-11).
For children ages 9–11 "friendships and peer relationships" increase in
strength, complexity, and importance. This results in greater "peer
pressure." They grow even less dependent on their families and they are
challenged academically. To meet this challenge, they increase their
attention span and learn to see other points of view.
Adolescence
Adolescence is the period of life between the onset of puberty and
the full commitment to an adult social role, such as worker, parent,
and/or citizen. It is the period known for the formation of personal and
social identity (see Erik Erikson) and the discovery of moral purpose (see William Damon). Intelligence is demonstrated through the logical use of symbols related
to abstract concepts and formal reasoning. A return to egocentric
thought often occurs early in the period. Only 35% develop the capacity
to reason formally during adolescence or adulthood. (Huitt, W. and
Hummel, J. January 1998)
It is divided into three parts, namely:
Early Adolescence: 9 to 13 years
Mid Adolescence: 13 to 15 years and
Late Adolescence: 15 to 18 years
The adolescent unconsciously explores questions such as "Who am I?
Who do I want to be?" Like toddlers, adolescents must explore, test
limits, become autonomous, and commit to an identity, or sense of self. Different roles, behaviors and ideologies
must be tried out to select an identity. Role confusion and inability
to choose vocation can result from a failure to achieve a sense of
identity through, for example, friends.
Early adulthood
Early adulthood generally refers to the period between ages 18 to 25,
and according to theorists such as Erik Erikson, is a stage where
development is mainly focused on maintaining relationships. Examples include creating bond of intimacy, sustaining friendships,
and ultimately making a family. Some theorists state that development of
intimacy skills rely on the resolution of previous developmental
stages. A sense of identity gained in the previous stages is also
necessary for intimacy to develop. If this skill is not learned the
alternative is alienation, isolation, a fear of commitment, and the
inability to depend on others.
A related framework for studying this part of the lifespan is that of emerging adulthood.
Scholars of emerging adulthood, such as Jeffrey Arnett, are not
necessarily interested in relationship development. Instead, this
concept suggests that people transition after their teenage years into a
period not characterized as relationship building and an overall sense
of constancy with life, but with years of living with parents, phases of
self-discovery, and experimentation.
Middle adulthood
Middle adulthood generally refers to the period between ages 25 to
69. During this period, middle-aged adults experience a conflict between
generativity and stagnation. They may either feel a sense of
contributing to society, the next generation, or their immediate
community; or develop a sense of purposelessness.
Physically, the middle-aged experience a decline in muscular
strength, reaction time, sensory keenness, and cardiac output. Also,
women experience menopause and a sharp drop in the hormone estrogen. Men experience an equivalent endocrine system event to menopause. Andropause
in males is a hormone fluctuation with physical and psychological
effects that can be similar to those seen in menopausal females. As men
age lowered testosterone levels can contribute to mood swings and a
decline in sperm count. Sexual responsiveness can also be affected, including delays in erection and longer periods of penile stimulation required to achieve ejaculation.
Old age
The World Health Organization finds "no general agreement on the age at which a person becomes old." Most "developed countries" set the age as 60 or 65. However, in developing countries inability to make "active contribution" to society, not chronological age, marks the beginning of old age. According to Erikson's stages of psychosocial development,
old age is the stage in which individuals assess the quality of their
lives. In reflecting on their lives, people in this age group develop a
feeling of integrity if deciding that their lives were successful or a
feeling of despair if evaluation of one's life indicates a failure to
achieve goals.
Physically, older people experience a decline in muscular
strength, reaction time, stamina, hearing, distance perception, and the
sense of smell. They also are more susceptible to diseases such as cancer and pneumonia due to a weakened immune system.
Programs aimed at balance, muscle strength, and mobility have been
shown to reduce disability among mildly (but not more severely) disabled
elderly.
Sexual expression depends in large part upon the emotional and
physical health of the individual. Many older adults continue to be
sexually active and satisfied with their sexual activity.
Mental disintegration may also occur, leading to dementia or ailments such as Alzheimer's disease. It is generally believed that crystallized intelligence increases up to old age, while fluid intelligence decreases with age. Whether or not normal intelligence increases or decreases with age depends on the measure and study. Longitudinal studies show that perceptual speed, inductive reasoning, and spatial orientation decline. An article on adult cognitive development reports that cross-sectional studies show that "some abilities remained stable into early old age."
Parenting
Parenting variables alone have typically accounted for 20 to 50 percent of the variance in child outcomes.
All parents have their own parenting styles. Parenting styles,
according to Kimberly Kopoko, are "based upon two aspects of parenting
behavior; control and warmth. Parental control refers to the degree to
which parents manage their children's behavior. Parental warmth refers
to the degree to which parents are accepting and responsive to their
children's behavior."
Parenting styles
The following parenting styles have been described in the child development literature:
Authoritative parenting is characterized as parents who have
high parental warmth, responsiveness, and demandingness, but rate low in
negativity and conflict. These parents are assertive but not intrusive or overly restrictive.
This method of parenting is associated with more positive social and
academic outcomes. The beneficial outcomes of authoritative parenting
are not necessarily universal. Among African American adolescents,
authoritative parenting is not associated with academic achievement
without peer support for achievement.
Children who are raised by authoritative parents are "more likely to
become independent, self-reliant, socially accepted, academically
successful, and well-behaved. They are less likely to report depression
and anxiety, and less likely to engage in antisocial behavior like
delinquency and drug use."
Authoritarian parenting is characterized by low levels of warmth and
responsiveness with high levels of demandingness and firm control. These parents focus on obedience and they monitor their children regularly.
In general, this style of parenting is associated with maladaptive
outcomes. The outcomes are more harmful for middle class boys than
girls, preschool white girls than preschool black girls, and for white
boys than Hispanic boys. Furthermore, the negative effects of authoritarian parenting among Asian Americans can be offset by positive peer support.
Finally, among African Americans, some elements of authoritarian
parenting such as firm control and physical discipline do not serve as
predictive factors for negative outcomes.
Permissive parenting is characterized by high levels of responsiveness combined with low levels of demandingness. These parents are lenient and do not necessarily require mature behavior. They allow for a high degree of self-regulation and typically avoid confrontation.Compared to children raised using the authoritative style, preschool girls raised in permissive families are less assertive.
Additionally, preschool children of both sexes are less cognitively
competent than those children raised under authoritative parenting
styles.
Rejecting or neglectful parenting is the final category. This is
characterized by low levels of demandingness and responsiveness. These
parents are typically disengaged in their child's lives, lacking
structure in their parenting styles and are unsupportive. Children in this category are typically the least competent of all the categories.
Mother and father factors
Parenting
roles in child development have typically focused on the role of the
mother. Recent literature, however, has looked toward the father as
having an important role in child development. Affirming a role for
fathers, studies have shown that children as young as 15 months benefit
significantly from substantial engagement with their father.
In particular, a study in the U.S. and New Zealand found the presence
of the natural father was the most significant factor in reducing rates
of early sexual activity and rates of teenage pregnancy in girls.
Furthermore, another argument is that neither a mother nor a father is
actually essential in successful parenting, and that single parents as
well as homosexual couples can support positive child outcomes.
According to this set of research, children need at least one
consistently responsible adult with whom the child can have a positive
emotional connection. Having more than one of these figures contributes
to a higher likelihood of positive child outcomes.
Divorce
Another
parental factor often debated in terms of its effects on child
development is divorce. Divorce in itself is not a determining factor
of negative child outcomes. In fact, the majority of children from
divorcing families fall into the normal range on measures of
psychological and cognitive functioning. A number of mediating factors play a role in determining the effects
divorce has on a child, for example, divorcing families with young
children often face harsher consequences in terms of demographic,
social, and economic changes than do families with older children.
Positive coparenting after divorce is part of a pattern associated with
positive child coping, while hostile parenting behaviors lead to a
destructive pattern leaving children at risk.
Additionally, direct parental relationship with the child also affects
the development of a child after a divorce. Overall, protective factors
facilitating positive child development after a divorce are maternal
warmth, positive father-child relationship, and cooperation between
parents.