Stage theories are based on the idea that elements in systems move through a pattern of distinct stages over time and that these stages can be described based on their distinguishing characteristics. Specifically, stages in cognitive development
have a constant order of succession, later stages integrate the
achievements of earlier stages, and each is characterized by a
particular type of structure of mental processes which is specific to
it. The time of appearance may vary to a certain extent depending upon
environmental conditions.
"Stage theory" can also be applied beyond psychology to describe
phenomena more generally where multiple phases lead to an outcome. The
term "stage theory" can thus be applied to various scientific,
sociological and business disciplines. In these contexts, stages may not
be as rigidly defined, and it is possible for individuals within the
multi-stage process to revert to earlier stages or skip some stages
entirely.
Piaget's theory of cognitive development
Jean Piaget's theory
consists of four stages: Sensorimotor: (birth to 2 years),
Preoperations: (2 to 7 years), Concrete operations: (7 to 11 years), and
Formal Operations: (11 to 16 years). Each stage has at least two
substages, usually called early and fully.
Underlying assumptions
Each stage lays the foundation for the next.
Everyone goes through the stages in the same order.
Each stage is qualitatively different. Meaning it is a change in nature, not just quantity
The child is an active learner. Basically they have to do it on their own, they cannot be told.
Sensorimotor stage (birth to 2 years)
This stage is represented when infants obtain some control over their surroundings by sensory and motor schemes. Infants start to identify their actions and the consequences of their actions.
A child comes into the world knowing almost nothing, but they have the potential that comes in the form of:
Infants use these potentials to explore and gain an understanding about themselves and the environment. They have a lack of object permanence,
which means they have little or no ability to conceive things as
existing outside their immediate vicinity. For example: when you place a
barrier, such as a piece of wood, in front of an object an infant will
believe that the object is nonexistent.
Object permanence
Study
Infants do not grasp the concept of object permanence when they
do not realize that an object exists even when it is not visible at the
moment.
When an object or toy is hidden from an infant they almost
immediately lose interest and fail to search for the toy. This is
common in infants that are eight months or younger.
Children who are around eight months can form a mental
representation of an object in their head proving that they obtain
object permanence (sensory motor stage)
Sensorimotor play
This play does not provide a purpose other than sensation:
Swinging on a swing; enjoys the movement
Singing songs and simply playing with sounds such as 'Tra-la-la." the sound's purpose is only for the satisfaction they bring
Some play includes listening, tasting and smelling
Substages of Piaget's sensorimotor stage
Substage
Age
Piaget's Label
Characteristics
1
Birth-1 month
Reflexes
Use of built-in schemes or reflexes such as sucking or looking; no
imitation; no ability to integrate information from several senses.
2
1-4 months
Primary circular reactions
Accommodation of basic schemes (grasping, looking, sucking), as baby
practices them endlessly. Beginning coordination of schemes from
different senses, such as looking toward a sound; baby does not yet link
bodily actions to some result outside the body.
3
4-8 months
Secondary circular reactions
Baby becomes much more aware of events outside his own body and
makes them happen again, in a kind of trial-and-error learning.
Imitation may occur, but only of schemes already in the baby's
repertoire. Beginning understanding of the "object concept."
4
8-12 months
Coordination of secondary schemes
Clear intentional means-ends behavior. The baby not only goes after
what she wants, but may combine two schemes to do so, such as knocking a
pillow away to reach a toy. Imitation of novel behaviors occurs, as
does transfer of information from one sense to another (cross-modal
transfer).
5
12-18 months
Tertiary circular reactions
"Experimentation" begins, in which the infant tries out new ways of
playing with or manipulating objects. Very active, very purposeful
trial-and-error exploration.
6
18-24 months
Beginning of representational thought
Development of use of symbols to represent objects or events. Child
understands that the symbol is separate from the object. Deferred
imitation first occurs at this stage.
Preoperational stage (2 to 7 years)
Preoperational
intelligence means the young child is capable of mental
representations, but does not have a system for organizing this thinking
(intuitive rather than logical thought).
The child is egocentric – which is they have problems distinguishing
from their own perceptions and perceptions of others.
A classic example is, a preoperational child will cover their eyes so
they can not see someone and think that that person can not see them
either.
The child also has rigid thinking, which involves the following:
Centration – a child will become completely fixed on one point,
not allowing them to see the wider picture. For example, focusing only
on the height of the container rather than both the height and width
when determining what has the biggest volume.
State – can only concentrate on what something looks like at that time.
Appearance – focuses on how something appears rather than reality.
Lack of Reversibility – can not reverse the steps they have taken.
Does not realize that one set of steps can be cancelled by another set
of steps.
Lack of Conservation – realizing that something can have the same properties even if it appears differently.
Concrete operations (7 to 11 years)
Intelligence is now both symbolic and logical.
Acquires ‘operations’ = a set of general rules and strategies.
The most critical part of operations is realizing ‘reversibility’ =
both physical and mental processes can be reversed and cancelled out by
others.
The concrete operational child will overcome the aspects of rigidity apparent in a preoperational child. These are:
lack of reversibility
states
appearance
conservation
The tasks of concrete operations are:
Seriation – putting items (such as toys) in height order.
Classification – the difference between two similar items such as daisies and roses.
Conservation – realising something can have same properties, even if it appears differently.
It is important to realise that operations and conservations do not
develop at the same time. They develop gradually and are not an ‘all or
nothing’ phenomenon. For example, the first to develop is number
conservation followed by mass conservation, area conservation, liquid
conservation and finally solid volume conservation.
Thinking is not abstract. It is limited to concrete phenomena and the
child’s own past experiences.
Formal operations (11 to 16 years)
Child is capable of formulating hypotheses and then testing them against reality.
Thinking is abstract, that is a child/adolescent can formulate all
the possible outcomes before beginning the problem. They are also
capable of deductive reasoning.
Limitations of Piaget's theory
A
popular criticism is that Piaget underestimated the abilities of an
infant. Studies have shown that they have more of a capacity in memory
and understanding of objects than he believed.
Neo-Piagetian and Post-Piagetian stage theories
Juan Pascaual-Leone was the first to propose a neo-Piagetian stage theory. Since that time there have been several neo-Piagetian theories of cognitive development.
Only the ones that cover at least infancy through adulthood are
mentioned here. These include the theories of Robbie Case, Grame
Halford, Andreas Demetriou and Kurt W. Fischer. The theory of Michael Commons' model of hierarchical complexity
is also relevant. The description of stages in these theories is more
elaborate and focuses on underlying mechanisms of information processing
rather than on reasoning as such. In fact, development in information
processing capacity is invoked to explain the development of reasoning.
More stages are described (as many as 15 stages), with 4 being added
beyond the stage of Formal operations. Most stage sequences map onto one
another. PostPiagetian stages are free of content and context and are
therefore very powerful and general.
Auguste Comte's Law of three stages in 'Plan de travaux scientifiques nécessaires pour réorganiser la société (Plan of scientific studies necessary for the reorganization of society, 1822).
Kessen,
W., & Kessel F. S., Bornstein M. H., & Sameroff A. J. (1991).
Contemporary constructions of the child: essays in honor of William
Kessen. Hillsdale, NJ: L. Erlbaum Associates.
Cognitive development is a field of study in neuroscience and psychology
focusing on a child's development in terms of information processing,
conceptual resources, perceptual skill, language learning, and other
aspects of the developed adult brain and cognitive psychology.
Qualitative differences between how a child processes their waking
experience and how an adult processes their waking experience are
acknowledged (Such as object permanence,
the understanding of logical relations, and cause-effect reasoning in
school age children). Cognitive development is defined in adult terms as
the emergence of ability to consciously cognize and consciously
understand and articulate their understanding. From an adult point of
view, cognitive development can also be called intellectual development.
Cognitive development is how a person perceives, thinks, and gains
understanding of their world through the relations of genetic and
learning factors. There are four stages to Cognitive Development
information development, reasoning, intelligence, language, and memory.
These stages start when the baby is about 18 months old, they play with
toys, listen to their parents speak, they watch tv, anything that
catches their attention helps build their Cognitive Development.
Jean Piaget was a major force establishing this field, forming his "theory of cognitive development". Piaget proposed four stages of cognitive development: the sensorimotor, preoperational, concrete operational and formal operational period.
Many of Piaget's theoretical claims have since fallen out of favor.
Still, his description of the most prominent changes in cognition with
age, is generally still accepted today (e.g., how early perception moves
from being dependent on concrete, external actions. Later, abstract
understanding of observable aspects of reality can be captured; leading
to, discovery of underlying abstract rules and principles, usually
starting in adolescence)
In recent years, however, alternative models have been advanced, including information-processing theory, neo-Piagetian theories of cognitive development,
which aim to integrate Piaget's ideas with more recent models and
concepts in developmental and cognitive science, theoretical cognitive
neuroscience, and social-constructivist approaches. A major controversy
in cognitive development has been "nature versus nurture",
that is, the question if cognitive development is mainly determined by
an individual's innate qualities ("nature"), or by their personal
experiences ("nurture"). However, it is now recognized by most experts
that this is a false dichotomy:
there is overwhelming evidence from biological and behavioral sciences
that from the earliest points in development, gene activity interacts
with events and experiences in the environment.
Historical origins: The history and theory of cognitive development
Jean
Piaget is inexorably linked to cognitive development. It is clear in
Piaget's writings that there are influences from many historical
predecessors. A few that are worth mentioning are included in the
following Historical Origins chart. It is intended to be a more
inclusive list of researchers who have studied the processes of
acquiring more complex ways of thinking as people grow and develop:
Wrote Emile, or On Education
(1762). He discusses childhood development as happening in three
stages. First stage, up to age 12, the child is guided by their emotions
and impulses. The second stage, ages 12–16, the child's reason starts
to develop. In the third and final stage, age 16 and up, the child
develops into an adult.
Wrote several books on childhood development, including Studies of Childhood (1895) and Children's Ways[6]
(1897). He used a detailed observational study method with the
children. Contemporary research in child development actually repeats
observations, and observational methods, summarized by Sully in Studies of Childhood, such as the mirror technique.
Area of specialty was developmental psychology. Main contribution is the somewhat controversial "zone of proximal development"
(ZPD) which states that play should be children's main activity as this
is their main source of development in terms of emotional, volitional,
and cognitive development. ZPD is the link between children's learning
and cognitive development.
She began her career working with mentally disabled children in
1897, then conducted observation and experimental research in elementary
schools. Wrote The Discovery of the Child (1948). Discussed the Four Planes of Development: birth–6, 6–12, 12–18, and 18–24. The Montessori Method
now has three developmentally-meaningful age groups: 2–2.5, 2.5–6, and
6–12. She was working on human behavior in older children but only
published lecture notes on the subject.
Piaget was the first psychologist and philosopher to brand this type
of study as "cognitive development". Other researchers, in multiple
disciplines, had studied development in children before, but Piaget is
often credited as being the first one to make a systematic study of
cognitive development and gave it its name. His main contribution is the
stage theory of child cognitive development. He also published his
observational studies of cognition in children, and created a series of
simple tests to reveal different cognitive abilities in children.
Wrote the theory of stages of moral development, which extended
Piaget's findings of cognitive development and showed that they continue
through the lifespan. Kohlberg's six stages follow Piaget's
constructivist requirements in that stages can not be skipped and it is
very rare to regress in stages. Notable works: Moral Stages and Moralization: The Cognitive-Development Approach[8] (1976) and Essays on Moral Development (1981)
Piaget's theory of cognitive development
Jean Piaget (1896–1980) believed that people move through stages of development that allow them to think in new, more complex ways.
Sensorimotor stage
The
first stage in Piaget's stages of cognitive development is the
sensorimotor stage. This stage lasts from birth to two years old. During
this stage, behaviors lack a sense of thought and logic. Behaviors
gradually move from acting upon inherited reflexes to interacting with
the environment with a goal in mind and being able to represent the
external world at the end.
The sensorimotor stage has been broken down into six sub stages
that explain the gradual development of infants from birth to age 2.
Once the child gains the ability to mentally represent reality, the
child begins the transition to the preoperational stage of development.
Birth to one month
Each
child is born with inherited reflexes that they use to gain knowledge
and understanding about their environment. Examples of these reflexes
include grasping and sucking.
1–4 months
Children
repeat behaviors that happen unexpectedly because of their reflexes.
For example, a child's finger comes in contact with the mouth and the
child starts sucking on it. If the sensation is pleasurable to the
child, then the child will attempt to recreate the behavior. Infants use their initial reflexes (grasping and sucking) to explore their environment and create schemes. Schemes are groups of similar actions or thoughts that are used repeatedly in response to the environment. Once a child begins to create schemes they use accommodation and assimilation to become progressively adapted to the world. Assimilation
is when a child responds to a new event in a way that is consistent
with an existing schema. For example, an infant may assimilate a new
teddy bear into their putting things in their mouth scheme and use their
reflexes to make the teddy bear go into their mouth. Accommodation
is when a child either modifies an existing scheme or forms an entirely
new schema to deal with a new object or event. For example, an infant
may have to open his or her mouth wider than usual to accommodate the
teddy bear's paw.
5–8 months
Child
has an experience with an external stimulus that they find pleasurable,
so they try to recreate that experience. For example, a child
accidentally hits the mobile above the crib and likes to watch it spin.
When it stops the child begins to grab at the object to make it spin
again. In this stage, habits are formed from general schemes that the
infant has created but there is not yet, from the child's point of view,
any differentiation between means and ends. Children cannot also focus on multiple tasks at once, and only focus on the task at hand.
The child may create a habit of spinning the mobile in its crib, but
they are still trying to find out methods to reach the mobile in order
to get it to spin in the way that they find pleasurable. Once there is
another distraction (say the parent walks in the room) the baby will no
longer focus on the mobile. Toys should be given to infants that respond
to a child's actions to help foster their investigative instincts. For example, a toy plays a song when you push one button, and then a picture pops up if you push another button.
8–12 months
Behaviors will be displayed for a reason rather than by chance. They begin to understand that one action can cause a reaction. They also begin to understand object permanence,
which is the realization that objects continue to exist when removed
from view. For example: The baby wants a rattle but the blanket is in
the way. The baby moves the blanket to get the rattle. Now that the
infant can understand that the object still exists, they can
differentiate between the object, and the experience of the object.
According to psychologist David Elkind, "An internal representation of
the absent object is the earliest manifestation of the symbolic function
which develops gradually during the second year of life whose
activities dominate the next stage of mental growth."
12–18 months
Actions
occur deliberately with some variation. For example, a baby drums on a
pot with a wooden spoon, then drums on the floor, then on the table.
18–24 months
Children
begin to build mental symbols and start to participate in pretend play.
For example, a child is mixing ingredients together but doesn't have a
spoon so they pretend to use one or use another object to replace the
spoon. Symbolic thought
is a representation of objects and events as mental entities or symbols
which helps foster cognitive development and the formation of
imagination.
According to Piaget, the infant begins to act upon intelligence rather
than habit at this point. The end product is established after the
infant has pursued for the appropriate means. The means are formed from
the schemes that are known by the child.
The child is starting to learn how to use what it has learned in the
first two years to develop and further explore their environment.
Preoperational stage
Lasts
from 2 years of age until 6 or 7. It can be characterized in two
somewhat different ways. In his early work, before he had developed his
structuralist theory of cognition, Piaget described the child's thoughts
during this period as being governed by principles such as egocentrism,
animism and other similar constructs. Egocentrism is when a child can
only see a certain situation his or her own way. One cannot comprehend
that other people have other views and perceptions of scenarios. Animism
is when an individual gives a lifeless object human-like qualities. An
individual usually believes that this object has human emotions,
thoughts and intentions. Once he had proposed his structuralist theory,
Piaget characterized the preoperational child as lacking the cognitive
structures possessed by the concrete operational child. The absence of
these structures explains, in part, the behaviors Piaget had previously
described as egocentric and animistic, for example, an inability to
comprehend that another individual may have different emotional
responses to similar experiences.
During this stage children also become increasingly adept at using
symbols as evidenced by the increase in playing and pretending.
Concrete operational stage
Lasts
from 6 or 7 years until about 12 or 13. During this stage, the child's
cognitive structures can be characterized by reality. Piaget argues that
the same general principles can be discerned in a wide range of
behaviors. One of the best-known achievements of this stage is
conservation. In a typical conservation experiment a child is asked to
judge whether or not two quantities are the same – such as two equal
quantities of liquid in a short and tall glass. A preoperational child
will typically judge the taller, thinner glass to contain more, while a
concrete operational child will judge the amounts still to be the same.
The ability to reason in this way reflects the development of a
principle of conservation.
Formal operational stage
This
stage lasts from 12 or 13 until adulthood, when people are advancing
from logical reasoning with concrete examples to abstract examples. The
need for concrete examples is no longer necessary because abstract
thinking can be used instead. In this stage adolescents are also able to
view themselves in the future and can picture the ideal life they would
like to pursue. Some theorists believe the formal operational stage can
be divided into two sub-categories: early formal operational and late
formal operation thought. Early formal operational thoughts may be just
fantasies, but as adolescents advance to late formal operational thought
the life experiences they have encountered changes those fantasy
thoughts to realistic thoughts.
Criticism
Many of Piaget's claims have fallen out of favor. For example, he claimed that young children cannot conserve
numbers. However, further experiments showed that children did not
really understand what was being asked of them. When the experiment is
done with candies, and the children are asked which set they want rather than having to tell an adult which is more, they show no confusion about which group has more items.
Piaget's theory of cognitive development ends at the formal
operational stage that is usually developed in early adulthood. It does
not take into account later stages of adult cognitive development as
described by, for example, Harvard University professor Robert Kegan.
Other theoretical perspectives on cognitive development
Lev Vygotsky's theory
Lev Vygotsky's
(1896-1934) theory is based on social learning as the most important
aspect of cognitive development. In Vygotsky's theory, adults are very
important for young children's development. They help children learn
through mediation, which is modeling and explaining concepts. Together,
adults and children master concepts of their culture and activities.
Vygotsky believed we get our complex mental activities through social
learning. A significant part of Vygotsky's theory is based on the zone
of proximal development, which he believes is when the most effective
learning takes place. The Zone of proximal development is what a child cannot accomplish alone but can accomplish with the help of an MKO (more knowledgeable other). Vygotsky
also believed culture is a very important part of cognitive development
such as the language, writing and counting system used in that culture.
Another aspect of Vygotsky’ theory is private speech. Private speech is
when a person talks to themselves in order to help themselves problem
solve. Scaffolding or providing support to a child and then slowly
removing support and allowing the child to do more on their own over
time is also an aspect of Vygotsky’s theory.
Speculated core systems of cognition
Empiricists
study how these skills may be learned in such a short time. The debate
is over whether these systems are learned by general-purpose learning
devices, or domain-specific cognition. Moreover, many modern cognitive
developmental psychologists, recognizing that the term "innate" does not
square with modern knowledge about epigenesis, neurobiological
development, or learning, favor a non-nativist framework. Researchers
who discuss "core systems" often speculate about differences in thinking
and learning between proposed domains.
Researchers who posit a set of so-called "core domains" suggest
that children have an innate sensitivity to specific kinds of patterns
of information. Those commonly cited include:
Number
Infants appear to have two systems for dealing with numbers. One deals with small numbers, often called subitizing. Another deals with larger numbers in an approximate fashion.
Space
Very young
children appear to have some skill in navigation. This basic ability to
infer the direction and distance of unseen locations develops in ways
that are not entirely clear. However, there is some evidence that it
involves the development of complex language skills between 3 and 5
years.
Also, there is evidence that this skill depends importantly on visual
experience, because congenitally blind individuals have been found to
have impaired abilities to infer new paths between familiar locations.
Visual perception
One of the original nativist versus empiricist debates was over depth perception. There is some evidence that children less than 72 hours old can perceive such complex things as biological motion.
However, it is unclear how visual experience in the first few days
contributes to this perception. There are far more elaborate aspects of
visual perception that develop during infancy and beyond.
Essentialism
Young children seem to be predisposed to think of biological entities (e.g., animals and plants) in an essentialistic way.
This means that they expect such entities (as opposed to, e.g.,
artifacts) to have many traits such as internal properties that are
caused by some "essence" (such as, in our modern Western conceptual
framework, the genome).
Language acquisition
A major, well-studied process and consequence of cognitive development is language acquisition.
The traditional view was that this is the result of deterministic,
human-specific genetic structures and processes. Other traditions,
however, have emphasized the role of social experience in language
learning. However, the relation of gene activity, experience, and
language development is now recognized as incredibly complex and
difficult to specify. Language development is sometimes separated into
learning of phonology (systematic organization of sounds), morphology
(structure of linguistic units—root words, affixes, parts of speech,
intonation, etc.), syntax (rules of grammar within sentence structure),
semantics (study of meaning), and discourse or pragmatics (relation
between sentences). However, all of these aspects of language
knowledge—which were originally posited by the linguist Noam Chomsky to be autonomous or separate—are now recognized to interact in complex ways.
Bilingualism
It wasn’t until recently
that bilingualism had been accepted as a contributing factor to
cognitive development. There have been a number of studies showing how
bilingualism contributes to the executive function of the brain, which
is the main center at which cognitive development happens. According to
Bialystok in “Bilingualism and the Development of Executive Function:
The Role of Attention”, children who are bilingual, have to actively
filter through the two different languages to select the one they need
to use, which in turn makes the development stronger in that center.
Whorf's hypothesis
Benjamin Whorf (1897–1941), while working as a student of Edward Sapir,
posited that a person's thinking depends on the structure and content
of their social group's language. In other words, it is the belief that
language determines our thoughts and perceptions. For example, it used
to be thought that the Greeks, who wrote left to right, thought
differently than Egyptians since the Egyptians wrote right to left.
Whorf's theory was so strict that he believed if a word is absent in a
language, then the individual is unaware of the object's existence.
This theory was played out in George Orwell's book, Animal Farm; the
pig leaders slowly eliminated words from the citizen's vocabulary so
that they were incapable of realizing what they were missing.
The Whorfian hypothesis failed to recognize that people can still be
aware of the concept or item, even though they lack efficient coding to
quickly identify the target information.
Quine's bootstrapping hypothesis
Willard Van Orman Quine (1908–2000) argued that there are innate conceptual biases
that enable the acquisition of language, concepts, and beliefs. Quine's
theory follows nativist philosophical traditions, such as the European
rationalist philosophers, for example Immanuel Kant.
Neo-Piagetian theories of cognitive development
Neo-Piagetian theories of cognitive development emphasized the role of
information processing mechanisms in cognitive development, such as
attention control and working memory. They suggested that progression
along Piagetian stages or other levels of cognitive development is a
function of strengthening of control mechanisms and enhancement of
working memory storage capacity.
Lev Vygotsky vs. Jean Piaget
Unlike Jean Piaget,
who believed development comes before learning, Vygotsky believed that
learning comes before development and that one must learn first to be
able to develop into a functioning human being. Vygotsky's theory is
different from Piaget's theory of cognitive development
in four ways. 1. Vygotsky believes culture affects cognitive
development more. Piaget thinks that cognitive development is the same
across the world, while Vygotsky has the idea that culture makes
cognitive development different. 2. Social factors heavily influence
cognitive development under Vygotsky's beliefs. Environment and parents
the child has will play a big role in a child's cognitive development.
The child learns through the Zone of Proximal Development with help from
their parent. 3. Vygotsky believes that language is important in
cognitive development. While Piaget considers thought as an important
role, Vygotsky sees thought and language as different, but eventually
coming together. Vygotsky emphasizes the role of inner speech being the
first thing to cause cognitive development to form. 4. Cognitive
development is strongly influenced by adults. Children observe adults in
their life and gain knowledge about their specific culture based on
things the adults around them do. They do this through mediation and
scaffolding.
Neuroscience
During development, especially the first few years of life, children show interesting patterns of neural development and a high degree of neuroplasticity.
Neuroplasticity, as explained by the World Health Organization, can be
summed up in three points. 1.) Any adaptive mechanism used by the
nervous system to repair itself after injury. 2.) Any means by which the
nervous system can repair individually damaged central circuits. 3.)
Any means by which the capacity of the central nervous system can adapt
to new physiological conditions and environment. The relation of brain
development and cognitive development is extremely complex and, since
the 1990s, has been a growing area of research.
Cognitive development and motor development may also be closely
interrelated. When a person experiences a neurodevelopmental disorder
and their cognitive development is disturbed, we often see adverse
effects in motor development as well. Cerebellum, which is the part of
brain that is most responsible for motor skills, has been shown to have
significant importance in cognitive functions in the same way that
prefrontal cortex has important duties in not only cognitive abilities
but also development of motor skills. To support this, there is evidence
of close co-activation of neocerebellum and dorsolateral prefrontal
cortex in functional neuroimaging as well as abnormalities seen in both
cerebellum and prefrontal cortex in the same developmental disorder. In
this way, we see close interrelation of motor development and cognitive
development and they cannot operate in their full capacity when either
of them are impaired or delayed.
Cultural influences
From
cultural psychologists' view, minds and culture shape each other. In
other words, culture can influence brain structures which then influence
our interpretation of the culture.
These examples reveal cultural variations in neural responses:
Figure-line task (Hedden et al., 2008)
Behavioral
research has shown that one's strength in independent or interdependent
tasks differ based on their cultural context. In general, East Asian
cultures are more interdependent whereas Western cultures are more
independent.
Hedden et al. assessed functional magnetic resonance imaging (fMRI)
responses of East Asians and Americans while they performed independent
(absolute) or interdependent (relative) tasks. The study showed that
participants used regions of the brain associated with attentional
control when they had to perform culturally incongruent tasks. In other
words, neural paths used for the same task were different for Americans
and East Asians (Hedden et al., 2008).
Transcultural neuroimaging studies (Han s. and Northoff G., 2008)
New
studies in transcultural neuroimaging studies have demonstrated that
one’s cultural background can influence the neural activity that
underlies both high (for example, social cognition) and low (for
example, perception) level cognitive functions. Studies demonstrated
that groups that come from different cultures or that have been exposed
to culturally different stimuli have differences in neural activity. For
example, differences were found in that of the pre motor cortex during
mental calculation and that of the VMPFC during trait judgements of
one’s mother from people with different cultural backgrounds. In
conclusion, since differences were found in both high-level and
low-level cognition one can assume that our brain’s activity is strongly
and, at least in part, constitutionally shaped by its sociocultural
context (Han s. and Northoff G., 2008).
Kobayashi et al., 2007
Kobayashi
et al. compared American-English monolingual and Japanese-English
bilingual children's brain responses in understanding others' intentions
through false-belief story and cartoon tasks. They found universal activation of the region bilateral ventromedial prefrontal cortex in theory of mind
tasks. However, American children showed greater activity in the left
inferior frontal gyrus during the tasks whereas Japanese children had
greater activity in the right inferior frontal gyrus during the Japanese
Theory of Mind tasks. In conclusion, these examples suggest that the
brain's neural activities are not universal but are culture dependent.
The theory of recapitulation, also called the biogenetic law or embryological parallelism—often expressed using Ernst Haeckel's phrase "ontogeny recapitulates phylogeny"—is a historical hypothesis that the development of the embryo of an animal, from fertilization to gestation or hatching (ontogeny), goes through stages resembling or representing successive adult stages in the evolution of the animal's remote ancestors (phylogeny). It was formulated in the 1820s by Étienne Serres based on the work of Johann Friedrich Meckel, after whom it is also known as Meckel–Serres law.
Since embryos also evolve in different ways,
the shortcomings of the theory had been recognized by the early 20th
century, and it had been relegated to "biological mythology" by the mid-20th century.
Analogies to recapitulation theory have been formulated in other fields, including cognitive development and art criticism.
The embryological theory was formalised by Serres in 1824–26,
based on Meckel's work, in what became known as the "Meckel-Serres Law".
This attempted to link comparative embryology with a "pattern of unification" in the organic world. It was supported by Étienne Geoffroy Saint-Hilaire,
and became a prominent part of his ideas. It suggested that past
transformations of life could have been through environmental causes
working on the embryo, rather than on the adult as in Lamarckism. These naturalistic ideas led to disagreements with Georges Cuvier. The theory was widely supported in the Edinburgh and London schools of higher anatomy around 1830, notably by Robert Edmond Grant, but was opposed by Karl Ernst von Baer's ideas of divergence, and attacked by Richard Owen in the 1830s.
Ernst Haeckel (1834–1919) attempted to synthesize the ideas of Lamarckism and Goethe's Naturphilosophie with Charles Darwin's
concepts. While often seen as rejecting Darwin's theory of branching
evolution for a more linear Lamarckian view of progressive evolution,
this is not accurate: Haeckel used the Lamarckian picture to describe
the ontogenetic and phylogenetic history of individual species, but
agreed with Darwin about the branching of all species from one, or a
few, original ancestors. Since early in the twentieth century, Haeckel's "biogenetic law" has been refuted on many fronts.
Haeckel formulated his theory as "Ontogeny recapitulates
phylogeny". The notion later became simply known as the recapitulation
theory. Ontogeny is the growth (size change) and development (structure change) of an individual organism; phylogeny is the evolutionary
history of a species. Haeckel claimed that the development of advanced
species passes through stages represented by adult organisms of more
primitive species.
Otherwise put, each successive stage in the development of an
individual represents one of the adult forms that appeared in its
evolutionary history.
For example, Haeckel proposed that the pharyngeal grooves between the pharyngeal arches
in the neck of the human embryo not only roughly resembled gill slits
of fish, but directly represented an adult "fishlike" developmental
stage, signifying a fishlike ancestor. Embryonic pharyngeal slits, which
form in many animals when the thin branchial plates separating
pharyngeal pouches and pharyngeal grooves perforate, open the pharynx to the outside. Pharyngeal arches appear in all tetrapod embryos: in mammals, the first pharyngeal arch develops into the lower jaw (Meckel's cartilage), the malleus and the stapes.
Haeckel produced several embryo drawings
that often overemphasized similarities between embryos of related
species. Modern biology rejects the literal and universal form of
Haeckel's theory, such as its possible application to behavioural
ontogeny, i.e. the psychomotor development of young animals and human
children.
Contemporary criticism
Drawing by Wilhelm His of chick brain compared to folded rubber tube, 1874. Ag (Anlage) = Optic lobes, matching bulges in rubber tube.
Haeckel's drawings misrepresented observed human embryonic
development to such an extent that he attracted the opposition of
several members of the scientific community, including the anatomist Wilhelm His, who had developed a rival "causal-mechanical theory" of human embryonic development.
His's work specifically criticised Haeckel's methodology, arguing that
the shapes of embryos were caused most immediately by mechanical
pressures resulting from local differences in growth. These differences
were, in turn, caused by "heredity". His compared the shapes of
embryonic structures to those of rubber tubes that could be slit and
bent, illustrating these comparisons with accurate drawings. Stephen Jay Gould noted in his 1977 book Ontogeny and Phylogeny
that His's attack on Haeckel's recapitulation theory was far more
fundamental than that of any empirical critic, as it effectively stated
that Haeckel's "biogenetic law" was irrelevant.
Darwin proposed that embryos resembled each other since they shared a
common ancestor, which presumably had a similar embryo, but that
development did not necessarily recapitulate phylogeny: he saw no reason
to suppose that an embryo at any stage resembled an adult of any
ancestor. Darwin supposed further that embryos were subject to less
intense selection pressure than adults, and had therefore changed less.
Modern status
Modern evolutionary developmental biology
(evo-devo) follows von Baer, rather than Darwin, in pointing to active
evolution of embryonic development as a significant means of changing
the morphology of adult bodies. Two of the key principles of evo-devo, namely that changes in the timing (heterochrony) and positioning (heterotopy)
within the body of aspects of embryonic development would change the
shape of a descendant's body compared to an ancestor's, were however
first formulated by Haeckel in the 1870s. These elements of his thinking
about development have thus survived, whereas his theory of
recapitulation has not.
The Haeckelian form of recapitulation theory is considered defunct.
Embryos do undergo a period where their morphology is strongly shaped
by their phylogenetic position, rather than selective pressures, but
that means only that they resemble other embryos at that stage, not
ancestral adults as Haeckel had claimed. The modern view is summarised by the University of California Museum of Paleontology:
Embryos do reflect the course of
evolution, but that course is far more intricate and quirky than Haeckel
claimed. Different parts of the same embryo can even evolve in
different directions. As a result, the Biogenetic Law was abandoned, and
its fall freed scientists to appreciate the full range of embryonic
changes that evolution can produce—an appreciation that has yielded
spectacular results in recent years as scientists have discovered some
of the specific genes that control development.
Applications to other areas
The idea that ontogeny recapitulates phylogeny has been applied to some other areas.
Cognitive development
English philosopher Herbert Spencer
was one of the most energetic proponents of evolutionary ideas to
explain many phenomena. In 1861, five years before Haeckel first
published on the subject, Spencer proposed a possible basis for a
cultural recapitulation theory of education with the following claim:
If
there be an order in which the human race has mastered its various
kinds of knowledge, there will arise in every child an aptitude to
acquire these kinds of knowledge in the same order... Education is a
repetition of civilization in little.
— Herbert Spencer
G. Stanley Hall
used Haeckel's theories as the basis for his theories of child
development. His most influential work, "Adolescence: Its Psychology and
Its Relations to Physiology, Anthropology, Sociology, Sex, Crime,
Religion and Education" in 1904
suggested that each individual's life course recapitulated humanity's
evolution from "savagery" to "civilization". Though he has influenced
later childhood development theories, Hall's conception is now generally
considered racist.
Developmental psychologist Jean Piaget favored a weaker version of the formula, according to which ontogeny parallels phylogeny because the two are subject to similar external constraints.
The Austrian pioneer of psychoanalysis, Sigmund Freud,
also favored Haeckel's doctrine. He was trained as a biologist under
the influence of recapitulation theory during its heyday, and retained a
Lamarckian outlook with justification from the recapitulation theory.
Freud also distinguished between physical and mental recapitulation,
in which the differences would become an essential argument for his theory of neuroses.
In the late 20th century, studies of symbolism and learning in
the field of cultural anthropology suggested that "both biological
evolution and the stages in the child's cognitive development follow
much the same progression of evolutionary stages as that suggested in
the archaeological record".
Art criticism
The musicologist Richard Taruskin
in 2005 applied the phrase "ontogeny becomes phylogeny" to the process
of creating and recasting art history, often to assert a perspective or
argument. For example, the peculiar development of the works by
modernist composer Arnold Schoenberg
(here an "ontogeny") is generalized in many histories into a
"phylogeny" – a historical development ("evolution") of Western music
toward atonal styles of which Schoenberg is a representative. Such historiographies
of the "collapse of traditional tonality" are faulted by art historians
as asserting a rhetorical rather than historical point about tonality's
"collapse".
Taruskin also developed a variation of the motto into the pun
"ontogeny recapitulates ontology" to refute the concept of "absolute
music" advancing the socio-artistic theories of the musicologist Carl Dahlhaus. Ontology
is the investigation of what exactly something is, and Taruskin asserts
that an art object becomes that which society and succeeding
generations made of it. For example, Johann Sebastian Bach's St. John Passion, composed in the 1720s, was appropriated by the Nazi regime in the 1930s for propaganda. Taruskin claims the historical development of the St John Passion (its ontogeny) as a work with an anti-Semitic
message does, in fact, inform the work's identity (its ontology), even
though that was an unlikely concern of the composer. Music or even an
abstract visual artwork can not be truly autonomous ("absolute") because
it is defined by its historical and social reception.
Craniometry is measurement of the cranium (the main part of the skull), usually the human cranium. It is a subset of cephalometry, measurement of the head, which in humans is a subset of anthropometry, measurement of the human body. It is distinct from phrenology, the pseudoscience that tried to link personality and character to head shape, and physiognomy,
which tried the same for facial features. However, these fields have
all claimed the ability to predict traits or intelligence.
More direct measurements involve examinations of brains from corpses, or more recently, imaging techniques such as MRI, which can be used on living persons. Such measurements are used in research on neuroscience and intelligence.
The cephalic index
Swedish professor of anatomy Anders Retzius (1796–1860) first used the cephalic index in physical anthropology
to classify ancient human remains found in Europe. He classified brains
into three main categories, "dolichocephalic" (from the Ancient Greekkephalê, head, and dolikhos, long and thin), "brachycephalic" (short and broad) and "mesocephalic" (intermediate length and width).
These terms were then used by Georges Vacher de Lapouge (1854–1936), one of the pioneers of scientific theories in this area and a theoretician of eugenics, who in L'Aryen et son rôle social (1899 – "The Aryan and his social role") divided humanity into various, hierarchized, different "races", spanning from the "Aryan white race, dolichocephalic", to the "brachycephalic" "mediocre and inert" race, best represented by the "Jew [sic]."
In 1784, Louis-Jean-Marie Daubenton, who wrote many comparative anatomy memoirs for the Académie française, published the Mémoire sur les différences de la situation du grand trou occipital dans l’homme et dans les animaux (which translates as Memoir on the Different Positions of the Occipital Foramen in Man and Animals).
Six years later, Pieter Camper
(1722–1789), distinguished both as an artist and as an anatomist,
published some lectures containing an account of his craniometrical
methods. These laid the foundation of all subsequent work.
Pieter Camper invented the "facial angle", a measure meant to determine intelligence
among various species. According to this technique, a "facial angle"
was formed by drawing two lines: one horizontally from the nostril to the ear; and the other perpendicularly from the advancing part of the upper jawbone to the most prominent part of the forehead.
Camper claimed that antique statues presented an angle of 90°,
Europeans of 80°, Black people of 70° and the orangutan of 58°, thus
displaying a hierarchic view of mankind, based on a decadent conception of history. This scientific research was continued by Étienne Geoffroy Saint-Hilaire (1772–1844) and Paul Broca (1824–1880).
In 1856, workers found in a limestone quarry the skull of a Neanderthal man, thinking it to be the remains of a bear. They gave the material to amateur naturalist Johann Karl Fuhlrott, who turned the fossils over to anatomist Hermann Schaaffhausen. The discovery was jointly announced in 1857, giving rise to paleoanthropology.
Measurements were first made to compare the skulls of men with
those of other animals. This wide comparison constituted the first
subdivision of craniometric studies. The artist-anatomist Camper's
developed a theory to measure the facial angle, for which he is chiefly
known in later anthropological literature.
Camper's work followed 18th-century scientific theories. His
measurements of facial angle were used to liken the skulls of
non-Europeans to those of apes.
"Craniometry" also played a role in the foundation of the United
States and the ideologies or racism that would become ingrained in the
American psyche. As John Jeffries articulates in The Collision of Culture
the Anglo-Saxon hegemony present in America during the eighteenth and
nineteenth century helped establish "The American School of Craniometry"
which helped establish the American and Western concept of race.
As Jeffries points out the rigid establishment of race in
eighteenth-century American society came from a new school of sciences
which sought to distance Anglo-Saxons
from the African American population. The distancing of the African
population in American society through craniometry helped greatly in the
efforts to scientifically prove they were inferior. The ideologies set
forth by this new "American School" of thought were then used to justify
maintaining an enslaved population to sustain the increasing number of
slave plantations in the American South during the eighteenth and nineteenth centuries.
In the 19th century the names of notable contributors to the
literature of craniometry quickly increased in number. While it is
impossible to analyse each contribution, or even record a complete list
of the names of the authors, notable researchers who used craniometric
methods to compare humans to other animals included Paul Broca (1824–1880), founder of the Anthropological Society in 1859 in France; and T. H. Huxley (1825–1895) of England.
Ernst Haeckel (1834–1919) became famous for his now outdated "recapitulation theory",
according to which each individual mirrored the evolution of the whole
species during his life. Although outdated, his work contributed then to
the examination of human life.
These researches on skulls and skeletons helped liberate 19th-century European science from its ethnocentric biases. In particular, Eugène Dubois' (1858–1940) discovery in 1891 in Indonesia of the "Java Man", the first specimen of Homo erectus to be discovered, demonstrated mankind's deep ancestry outside Europe.
Cranial capacity, races and 19th–20th-century scientific ideas
Samuel George Morton (1799–1851), one of the inspirers of physical anthropology,
collected hundreds of human skulls from all over the world and started
trying to find a way to classify them according to some logical
criterion. Influenced by the common theories of his time, he claimed
that he could judge the intellectual capacity of a race by the cranial capacity (the measure of the volume of the interior of the skull).
After inspecting three mummies from ancient Egyptian catacombs,
Morton concluded that Caucasians and other races were already distinct
three thousand years ago. Since the bible indicated that Noah's Ark had washed up on Mount Ararat,
only a thousand years ago before this, Morton claimed that Noah's sons
could not possibly account for every race on earth. According to Mortons
theory of polygenism, races have been separate since the start.
Morton claimed that he could judge the intellectual capacity of a race by the skull
size. A large skull meant a large brain and high intellectual capacity,
and a small skull indicated a small brain and decreased intellectual
capacity. Morton collected hundreds of human skulls from all over the
world. By studying these skulls he claimed that each race had a separate
origin. Morton had many skulls from ancient Egypt, and concluded that
the ancient Egyptians were not African, but were White. His two major monographs were the Crania Americana (1839), An Inquiry into the Distinctive Characteristics of the Aboriginal Race of America and Crania Aegyptiaca (1844).
Based on craniometry data, Morton claimed in Crania Americana
that the Caucasians had the biggest brains, averaging 87 cubic inches,
Indians were in the middle with an average of 82 cubic inches and
Negroes had the smallest brains with an average of 78 cubic inches.
Stephen Jay Gould (1941–2002), an American paleontologist, evolutionary biologist and historian of science, studied these craniometric works in The Mismeasure of Man
(1981) and claimed Samuel Morton had fudged data and "overpacked" the
skulls with filler in order to justify his preconceived notions on
racial differences. A subsequent study by the anthropologist
John Michael found Morton's original data to be more accurate than
Gould describes, concluding that "[c]ontrary to Gould's
interpretation... Morton's research was conducted with integrity."
In 2011, physical anthropologists at the University of
Pennsylvania, which owns Morton's collection, published a study that
concluded that almost every detail of Gould's analysis was wrong and
that "Morton did not manipulate his data to support his preconceptions,
contra Gould." They identified and remeasured half of the skulls used
in Morton's reports, finding that in only 2% of cases did Morton's
measurements differ significantly from their own and that these errors
either were random or gave a larger than accurate volume to African
skulls, the reverse of the bias that Gould imputed to Morton.
Morton's followers, particularly Josiah C. Nott and George Gliddon in their monumental tribute to Morton's work, Types of Mankind (1854), carried Morton's ideas further and backed up his findings which supported the notion of polygenism.
Furthermore, Josiah Nott was the translator of Arthur de Gobineau's An Essay on the Inequality of the Human Races
(1853–1855), which is one of the founding works of the group of studies
that segregates society based on "race", in contrast to Boulainvilliers' (1658–1722) theory of races. Henri de Boulainvilliers opposed the Français (French people), alleged descendants of the Nordic Franks, and members of the aristocracy, to the Third Estate, considered to be indigenous Gallo-Roman people who were subordinated by the Franks by right of conquest.
Gobineau, meanwhile, made three main divisions between races, based not
on colour but on climatic conditions and geographic location, and which
privileged the "Aryan" race.
In 1873, Paul Broca (1824–1880) found the same pattern described by Samuel Morton's Crania Americana by weighing brains at autopsy.
Other historical studies alleging a Black-White difference in brain
size include Bean (1906), Mall, (1909), Pearl, (1934) and Vint (1934).
Furthermore, Georges Vacher de Lapouge's racial classification ("Teutonic", "Alpine" and "Mediterranean") was re-used by William Z. Ripley (1867–1941) in The Races of Europe (1899), who even made a map of Europe according to the alleged cephalic index of its inhabitants.
In Germany, Rudolf Virchow launched a study of craniometry, which gave surprising results according to contemporary theories on the "Aryan race", leading Virchow to denounce the "Nordic mysticism" in the 1885 Anthropology Congress in Karlsruhe.
Josef Kollmann,
a collaborator of Virchow, stated in the same congress that the people
of Europe, be them German, Italian, English or French, belonged to a
"mixture of various races," furthermore declaring that the "results of
craniology" led to "struggle against any theory concerning the
superiority of this or that European race" on others.
Virchow later rejected measure of skulls as legitimate means of taxinomy. Paul Kretschmer quoted an 1892 discussion with him concerning these criticisms, also citing Aurel von Törok's 1895 work, who basically proclaimed the failure of craniometry.
Craniometry, phrenology and physiognomy
Craniometry was also used in phrenology,
which purported to determine character, personality traits, and
criminality on the basis of the shape of the head and thus of the skull.
At the turn of the 19th century, Franz Joseph Gall (1758–1822) developed "cranioscopy" (Ancient Greek kranion: skull, scopos:
vision), a method to determine the personality and development of
mental and moral faculties on the basis of the external shape of the
skull.
Cranioscopy was later renamed to phrenology (phrenos: mind, logos: study) by his student Johann Spurzheim (1776–1832), who wrote extensively on the "Drs. Gall and Spurzheim's physiognomical System." Physiognomy claimed a correlation between physical features (especially facial features) and character traits.
It was made famous by Cesare Lombroso (1835–1909), the founder of anthropological criminology,
who claimed to be able to scientifically identify links between the
nature of a crime and the personality or physical appearance of the
offender. The originator of the concept of a "born criminal" and arguing in favor of biological determinism, Lombroso tried to recognize criminals by measurements of their bodies.
He concluded that skull and facial features were clues to genetic
criminality, and that these features could be measured with
craniometers and calipers with the results developed into quantitative
research. A few of the 14 identified traits of a criminal included large
jaws, forward projection of jaw, low sloping forehead; high cheekbones, flattened or upturned nose; handle-shaped ears; hawk-like noses or fleshy lips; hard shifty eyes; scanty beard or baldness; insensitivity to pain; long arms, and so on.
Criticisms and revival of past cranial theories in the 20th century
An 1839 drawing by Samuel George Morton of "a Negro head… a Caucasian skull… a Mongol head."
After being a main influence of US white supremacists, William Ripley's The Races of Europe (1899) was eventually rewritten in 1939, just before World War II, by Harvard physical anthropologist Carleton S. Coon.
J. Philippe Rushton, psychologist and author of the controversial work Race, Evolution and Behavior (1995), reanalyzed Gould's retabulation in 1989, and argued that Samuel Morton, in his 1839 book Crania Americana, had shown a pattern of decreasing brain size proceeding from East Asians, Europeans, and Africans.
In his 1995 book Race, Evolution, and Behavior, he alleged an average endocranial volume of 1,364 cm3 for East Asians, 1,347 for white caucasians and 1,268 for black Africans.
Other similar claims were previously made by Ho et al. (1980), who
measured 1,261 brains at autopsy, and Beals et al. (1984), who measured
approximately 20,000 skulls, finding the same East Asian → European → African
pattern. However, in the same article Beals explicitly warns against
using the findings as indicative of racial traits, "If one merely lists
such means by geographical region or race, causes of similarity by
genogroup and ecotype are hopelessly confounded".
Rushton's findings have also been criticized for questionable
methodology. Such as lumping in African-Americans with equatorial
Africans, who generally have smaller crania as people from hot climates
often have slightly smaller crania,
in craniometry studies. He has also compared equatorial Africans from
the poorest and least educated areas of Africa against Asians from the
wealthiest and most educated areas of Asia and areas with colder
climates which generally induce larger cranium sizes in evolution. According to Zack Cernovsky, from one of Rushton's own study
emerges that the average cranial capacity for North American blacks is
similar to the average for Caucasians from comparable climatic zones,
however a previous work by Rushton showed appreciable differences in
cranial capacity between North Americans of different race.
This is consistent with the findings of Z. Z. Cernovsky that people
from different climates tend to have minor differences in brain size.
Though differences in size does not necessarily imply differences in
intelligence. Though women tend to have smaller brains than men they
also have more neural complexity and loading in certain areas of the
brain than men.
Modern use
More direct measurements involve examinations of brains from corpses, or more recently, imaging techniques such as MRI, which can be used on living persons. Such measurements are used research on neuroscience and intelligence.
Brain volume data and other craniometric data are used in
mainstream science to compare modern-day animal species, and to analyze
the evolution of the human species in archaeology.
Measurements of the skull based on specific anatomical reference
points are used in both forensic facial reconstruction and portrait
sculpture.