Hereditarianism is the doctrine or school of thought that heredity plays a significant role in determining human nature and character traits, such as intelligence and personality. Hereditarians believe in the power of genetics
to explain human character traits and solve human social and political
problems. Hereditarians adopt the view that an understanding of human evolution can extend the understanding of human nature.
Overview
Social scientist Barry Mehler
defines hereditarianism as "the belief that a substantial part of both
group and individual differences in human behavioral traits are caused
by genetic differences". Hereditarianism is sometimes used as a synonym for biological or genetic determinism,
though some scholars distinguish the two terms. When distinguished,
biological determinism is used to mean that heredity is the only factor.
Supporters of hereditarianism reject this sense of biological
determinism for most cases. However, in some cases genetic determinism
is true; for example, Matt Ridley describes Huntington's disease as "pure fatalism, undiluted by environmental variability". In other cases, hereditarians would see no role for genes; for example, the condition of "not knowing a word of Chinese" has nothing to do (directly) with genes.
Hereditarians point to the heritability of cognitive ability, and
the outsized influence that cognitive ability has on life outcomes, as
evidence in favor of the hereditarian viewpoint.
According to Plomin and Van Stumm (2018), "Intelligence is highly
heritable and predicts important educational, occupational and health
outcomes better than any other trait." Estimates for the heritability of intelligence range from 20% in infancy to 80% in adulthood.
History
Francis Galton is generally considered the father of hereditarianism. In his book Hereditary Genius (1869), Galton pioneered research on the heredity of intelligence. Galton continued research into the heredity of human behavior in his later works, including "The History of Twins" (1875) and Inquiries into Human Faculty and Its Development (1883).
The Bell Curve (1994), by psychologist Richard Herrnstein and political scientist Charles Murray,
argued that the heritability of cognitive ability, combined with a
modern American society in which cognitive ability is the leading
determinant of success, was leading to an increasingly rich and
segregated "cognitive elite". Herrnstein and Murray also examined how cognitive ability predicts socially desirable behavior. They also discussed the debate regarding race and intelligence,
concluding that the evidence to date didn't justify an estimate on the
degree of influence of genetics versus environmental causes for average
differences in IQ test performance between racial groups.
Today the scientific consensus is that genetics does not explain such
differences, and that they are rather environmental in origin.
Cognitive psychologist Steven Pinker, in his book The Blank Slate (2002), argues that biology explains much more about human nature than people generally acknowledge.
Competing theories
Theories opposed to hereditarianism include behaviorism, social determinism and environmental determinism. This disagreement and controversy is part of the nature versus nurture debate. But both are based on the assumption that genes and environment have large independent effects.
The dominant view outside psychology among biologists and geneticists
is that both of these are gross oversimplifications and that the
behavioral/psychological phenotype for human beings is determined by a
function of genes and environment which cannot be decomposed into a sum
of functions of the two independently. And this especially because human behavior is uniquely plastic compared to that of other animals. The commonly cited heritability, h2, is meaningful only in the context of the independent effects model.
This model may be a good approximation to the real function given that
the range of genomes and the range of environments is sufficiently
narrow, e.g., white upper middle class Americans living in Chicago.
Ronald C. Bailey argues that hereditarianism is based on five
fallacious assumptions. In a 1997 paper, he also wrote that "...behavior
geneticists will continue to be very limited in their ability to
partition the effects of genes, the environment, and their covariance
and interaction on human behavior and cognitive ability."
Political implications
In 1949, Nicolas Pastore claimed that hereditarians were more likely to be conservative,
that they view social and economic inequality as a natural result of
variation in talent and character. Consequently, they explain class and
race differences as the result of partly genetic group differences.
Pastore contrasted this with the claim that behaviorists were more likely to be liberals or leftists, that they believe economic disadvantage and structural problems in the social order were to blame for group differences.
However, the historical correspondence between hereditarianism
and conservatism has broken down at least among proponents of
hereditarianism. Philosopher Peter Singer describes his vision of a new liberal political view that embraces hereditarianism in his 1999 book, A Darwinian Left.
Environmental determinism (also known as climatic determinism or geographical determinism) is the study of how the physical environment predisposes societies and states towards particular development trajectories. Jared Diamond, Jeffrey Herbst, Ian Morris,
and other social scientists sparked a revival of the theory during the
late twentieth and early twenty-first centuries. This "neo-environmental
determinism" school of thought examines how geographic and ecological
forces influence state-building, economic development, and institutions. Many scholars underscore that this original approach was used to encourage colonialism and eurocentrism,
and devalued human agency in non-Western societies, whereas modern
figures like Diamond have instead used the approach as an explanation
that rejects racism.
A history of thought
Classical and medieval periods
Early theories of environmental determinism in Ancient China, Ancient Greece, Ancient Rome suggested that environmental features completely determined the physical and intellectual qualities of whole societies. Guan Zhong (720–645 BC), an early
chancellor in China, held that the qualities of major rivers shaped the
character of surrounding peoples. Swift and twisting rivers made people
"greedy, uncouth, and warlike". The ancient Greek philosopher Hippocrates wrote a similar account in his treatise "Airs, Waters, Places".
Writers in the medieval Middle East also produced theories of environmental determinism. The Afro-Arab writer al-Jahiz argued that the skin color of people and livestock were determined by the water, soil, and heat of their environments. He compared the color of black basalt in the northern Najd to the skin color of the peoples living there to support his theory.
Ibn Khaldun, the Arab sociologist and polymath, similarly linked skin color to environmental factors. In his Muqaddimah (1377), he wrote that black skin was due to the hot climate of sub-Saharan Africa and not due to African lineage. He thereby challenged Hamitic theories of race that held that the sons of Ham (son of Noah) were cursed with black skin. Many writings of Ibn Khaldun were translated during the colonial era in order to advance the colonial propaganda machine.
Ibn Khaldun believed that the physical environment influenced
non-physical factors in addition to skin color. He argued that soil,
climate, and food determined whether people were nomadic or sedentary, and what customs and ceremonies they held. His writings may have influenced the later writings of Montesquieu during the 18th century through the traveller Jean Chardin, who travelled to Persia and described theories resembling those of Ibn Khaldun.
Environmental determinism has been widely criticized as a tool to legitimize colonialism, racism, and imperialism in Africa, The Americas, and Asia.
Environmental determinism enabled geographers to scientifically justify
the supremacy of white European races and the naturalness of
imperialism. The scholarship bolstered religious justifications and in some cases superseded them during the late 19th century.
Many writers, including Thomas Jefferson,
supported and legitimized African colonization by arguing that tropical
climates made the people uncivilized. Jefferson argued that tropical
climates encouraged laziness, relaxed attitudes, promiscuity and
generally degenerative societies, while the frequent variability in the
weather of the middle and northern latitudes led to stronger work ethics
and civilized societies. Adolf Hitler also made use of this theory to extol the supremacy of the Nordic race.
Defects of character supposedly generated by tropical climates were believed to be inheritable under the Lamarckian theory of inheritance of acquired characteristics, a discredited precursor to the Darwinian theory of natural selection.
The theory begins with the observation that an organism faced with
environmental pressures may undergo physiological changes during its
lifetime through the process of acclimatization.
Lamarckianism suggested that those physiological changes may be passed
directly to offspring, without the need for offspring to develop the
trait in the same manner.
Geographical societies like the Royal Geographical Society and the Société de géographie supported imperialism by funding explorers and other colonial proponents. Scientific societies acted similarly. Acclimatization societies
directly supported colonial enterprises and enjoyed their benefits. The
writings of Lamarck provided theoretical backing for the
acclimatization doctrines. The Société Zoologique d'Acclimatation was
largely founded by Isidore Geoffroy Saint-Hilaire—son of Étienne Geoffroy Saint-Hilaire, a close colleague and supporter of Lamarck.
Ellen Churchill Semple, a prominent environmental determinism scholar, applied her theories in a case study which focused on the Philippines, where she mapped civilization and wildness onto the topography of the islands.
Other scholars argued that climate and topography caused specific
character traits to appear in a given populations. Scholars thereby
imposed racial stereotypes on whole societies. Imperial powers rationalized labor exploitation by claiming that tropical peoples were morally inferior.
The role of environmental determinism in rationalizing and legitimizing racism, ethnocentrism and economic inequality has consequently drawn strong criticism.
David Landes similarly condemns of what he terms the unscientific moral geography of Ellsworth Huntington.
He argues that Huntington undermined geography as a science by
attributing all human activity to physical influences so that he might
classify civilizations hierarchically – favoring those civilizations he
considered best.
Late-20th-century growth of neo-environmental determinism
Environmental determinism was revived in the late-twentieth century as neo-environmental determinism, a new term coined by the social scientist and critic Andrew Sluyter. Sluyter argues that neo-environmental determinism does not sufficiently break with its classical and imperial precursors. Others have argued that in a certain sense a Darwinian approach to determinism is useful in shedding light on human nature.
Neo-environmental determinism examines how the physical
environment predisposes societies and states towards particular
trajectories of economic and political development. It explores how
geographic and ecological forces influence state-building, economic development, and institutions. It also addresses fears surrounding the effects of modern climate change. Jared Diamond was influential in the resurgence of environmental determinism due to the popularity of his book Guns, Germs, and Steel, which addresses the geographic origins of state formation prior to 1500 A.D.
Neo-environmental determinism scholars debate how much the physical environment shapes economic and political institutions. Economic historians Stanley Engerman and Kenneth Sokoloff argue that factor endowments
greatly affected "institutional" development in the Americas, by which
they mean the tendency to more free (democratic, free market) or unfree
(dictatorial, economically restrictive) regimes.
In contrast, Daron Acemoglu, Simon Johnson, and James A. Robinson underscore that the geographic factors most influenced institutional development during early state formation and colonialism.
They argue that geographic differences cannot explain economic growth
disparities after 1500 A.D. directly, except through their effects on
economic and political institutions.
Economists Jeffrey Sachs and John Luke Gallup
have examined the direct impacts of geographic and climatic factors on
economic development, especially the role of geography on the cost of
trade and access to markets, the disease environment, and agricultural
productivity.
In the Pulitzer Prize winning Guns, Germs, and Steel (1999), author Jared Diamond
points to geography as the answer to why certain states were able to
grow and develop faster and stronger than others. His theory cited the
natural environment and raw materials a civilization was blessed with as
factors for success, instead of popular century old claims of racial
and cultural superiority. Diamond says that these natural endowments
began with the dawn of man, and favored Eurasian civilizations due to
their location along similar latitudes, suitable farming climate, and
early animal domestication.
Diamond argues that early states located along the same latitude
lines were uniquely suited to take advantage of similar climates, making
it easier for crops, livestock, and farming techniques to spread. Crops
such as wheat and barley
were simple to grow and easy to harvest, and regions suitable for their
cultivation saw high population densities and the growth of early
cities. The ability to domesticate herd animals, which had no natural
fear of humans, high birth rates, and an innate hierarchy, gave some
civilizations the advantages of free labor, fertilizers, and war
animals. The east–west orientation of Eurasia allowed for knowledge
capital to spread quickly, and writing systems to keep track of advanced
farming techniques gave people the ability to store and build upon a
knowledge base across generations. Craftsmanship flourished as a surplus
of food from farming allowed some groups the freedom to explore and
create, which led to the development of metallurgy
and advances in technology. While the advantageous geography helped to
develop early societies, the close proximity in which humans and their
animals lived led to the spread of disease across Eurasia. Over several
centuries, rampant disease decimated populations, but ultimately led to
disease resistant communities. Diamond suggests that these chains of
causation led to European and Asian civilizations holding a dominant
place in the world today.
Diamond uses the Spanish conquistadors'
conquering of the Americas as a case study for his theory. He argues
that the Europeans took advantage of their environment to build large
and complex states complete with advanced technology and weapons. The Incans
and other native groups were not as blessed, suffering from a
north–south orientation that prevented the flow of goods and knowledge
across the continent. The Americas also lacked the animals, metals, and
complex writing systems of Eurasia which prevented them from achieving
the military or biological protections needed to fight off the European
threat.
Diamond's theory has not gone without criticism.
It was notably attacked for not providing enough detail
regarding causation of environmental variables, and for leaving logical
gaps in reasoning. Geographer Andrew Sluyter argued that Diamond was
just as ignorant as the racists of the 19th century. Sluyter challenged
Diamond's theory since it seemed to suggest that environmental
conditions lead to gene selection, which then lead to wealth and power
for certain civilizations. Sluyter also attacks environmental
determinism by condemning it as a highly studied and popular field based
entirely on Diamond's "quick and dirty" combination of natural and
social sciences.
Daron Acemoglu and James A. Robinson similarly criticized Diamond's work in their book Why Nations Fail.
They contend that the theory is outdated and can not effectively
explain differences in economic growth after 1500 or the reasons why
states that are geographically close can exhibit vast differences in
wealth. They instead favored an institutional approach in which a
society's success or failure is based on the underlying strength of its
institutions.
Writing in response to institutional arguments, Diamond agreed that
institutions are an important cause, but argued that their development
is often heavily influenced by geography, such as the clear regional
pattern in Africa where the northern and southern countries are
wealthier than those in the tropical regions.
Geography and pre-colonial African state-building
The effects of climate and land abundance on the development of state systems
In his book States and Power in Africa, political scientist Jeffrey Herbst
argues that environmental conditions help explain why, in contrast to
other parts of the world such as Europe, many pre-colonial societies in
Africa did not develop into dense, settled, hierarchical societies with
strong state control that competed with neighboring states for people
and territory.
Herbst argues that the European state-building experience was
highly idiosyncratic because it occurred under systemic geographic
pressures that favored wars of conquest – namely, passable terrain, land scarcity, and high-population densities.
Faced with the constant threat of war, political elites sent
administrators and armed forces from the urban centers into rural
hinterlands to raise taxes, recruit soldiers, and fortify buffer zones.
European states consequently developed strong institutions and
capital-periphery linkages.
By contrast, geographic and climatic factors in pre-colonial
Africa made establishing absolute control over particular pieces of land
prohibitively costly.
For example, because African farmers relied on rain-fed agriculture and
consequently invested little in particular pieces of land, they could
easily flee rulers rather than fight.
Some early African empires, like the Ashanti Empire, successfully projected power over large distances by building roads. The largest pre-colonial polities arose in the Sudanian Savanna
belt of West Africa because the horses and camels could transport
armies over the terrain. In other areas, no centralized political
organizations existed above the village level.
African states did not develop more responsive institutions under colonial rule or post-independence.
Colonial powers had little incentive to develop state institutions to
protect their colonies against invasion, having divided up Africa at the
Berlin Conference. The colonizers instead focused on exploiting natural resources and exploitation colonialism.
Dr. Marcella Alsan argues the prevalence of the tsetse fly hampered early state formation in Africa.
Because the tsetse virus was lethal to cows and horses, communities
afflicted by the insect could not rely on the agricultural benefits
provided by livestock.
African communities were prevented from stockpiling agricultural
surplus, working the land, or eating meat. Because the disease
environment hindered the formation of farming communities, early African
societies resembled small hunter-gatherer groups and not centralized states.
The relative availability of livestock animals enabled European
societies to form centralized institutions, develop advanced
technologies, and create an agricultural network. They could rely on their livestock to reduce the need for manual labor. Livestock also diminished the comparative advantage of owning slaves.
African societies relied on the use of rival tribesman as slave labor
where the fly was prevalent, which impeded long-term societal
cooperation.
Alsan argues that her findings support the view of Kenneth Sokoloff and Stanley Engerman that factor endowments shape state institutions.
Carl Troll has argued that the development of the Inca state in the central Andes was aided by conditions that allow for the elaboration of the staple foodchuño. Chuño, which can be stored for long times, is made of potato dried at freezing temperatures that are common at nighttime in the southern Peruvian highlands. Contradicting the link between the Inca state and dried potato is that other crops such as maize can also be preserved with only sun. Troll also argued that llamas, the Incas' pack animal, can be found in their largest numbers in this very same region. It is worth considering that the maximum extent of the Inca Empire coincided with the greatest distribution of alpacas and llamas. As a third point Troll pointed out irrigation technology as advantageous to the Inca state-building.
While Troll theorized environmental influences on the Inca Empire, he
opposed environmental determinism, arguing that culture lay at the core
of the Inca civilization.
Effects of geography on political regimes
Numerous scholars have argued that geographic and environmental factors affect the types of political regime that societies develop, and shape paths towards democracy versus dictatorship.
Daron Acemoglu, Simon Johnson, and James A. Robinson
have achieved notoriety for demonstrating that diseases and terrain
have helped shape tendencies towards democracy versus dictatorship, and
through these economic growth and development. In their book Why Nations Fail, as well as a paper titled The Colonial Origins of Comparative Development: An Empirical Investigation,
the authors show that the colonial disease environment shaped the
tendency for Europeans to settle the territory or not, and whether they
developed systems of agriculture and labor markets that were free and
egalitarian versus exploitative and unequal. These choices of political
and economic institutions, they argue, shaped tendencies to democracy or
dictatorship over the following centuries.
In order to understand the impact and creation of institutions during early state formation, economic historians Stanley Engerman and Kenneth Sokoloff examined the economic development of the Americas during colonization. They found that the beginnings of the success or failure of American colonies were based on the specific factor endowments
available to each colony. These endowments included the climate, soil
profitability, crop potential, and even native population density.
Institutions formed to take advantage of these factor endowments. Those
that were most successful developed an ability to change and adapt to
new circumstances over time. For example, the development of economic
institutions, such as plantations, was caused by the need for a large property and labor force to harvest sugar and tobacco, while smallholder
farms thrived in areas where scale economies were absent. Though
initially profitable, plantation colonies also suffered from large
dependent populations over time as slaves and natives were given few
rights, limiting the population available to drive future economic
progress and technological development.
Factor endowments also influenced political institutions. This is
demonstrated by the plantation owning elite using their power to secure
long lasting government institutions and pass legislation that leads to
the persistence of inequality in society. Engerman and Sokoloff found
smallholder economies to be more equitable since they discouraged an
elite class from forming, and distributed political power democratically
to most land-owning males. These differences in political institutions
were also highly influential in the development of schools, as more
equitable societies demanded an educated population to make political
decisions. Over time these institutional advantages had exponential
effects, as colonies with educated and free populations were better
suited to take advantage of technological change during the industrial
revolution, granting country wide participation into the booming
free-market economy.
Engerman and Sokoloff conclude that while institutions heavily
influenced the success of each colony, no individual type of institution
is the source of economic and state growth. Other variables such as
factor endowments, technologies, and the creation of property rights are
just as crucial in societal development. To encourage state success an
institution must be adaptable and suited to find the most economical
source of growth. The authors also argue that while not the only means
for success, institutional development has long lasting-economic and
social effects on the state.
Other prominent scholars contest the extent to which factor endowments determine economic and political institutions.
American economists William Easterly and Ross Levine
argue that economic development does not solely depend on geographic
endowments—like temperate climates, disease-resistant climates, or soil
favorable to cash crops. They stress that there is no evidence that geographic endowments influence country incomes other than through institutions. They observe that states like Burundi
are poor—despite favorable environmental conditions like abundant
rainfall and fertile soil—because of the damage wrought by colonialism.
Other states like Canada with fewer endowments are more stable and have higher per capita incomes.
Easterly and Levine further observe that studies of how the
environment directly influences land and labor were tarred by racist
theories of underdevelopment, but that does not mean that such theories
can be automatically discredited. They argue that Diamond correctly
stresses the importance of germs and crops in the very long-run of
societal technological development. They find that regression results support the findings of Jared Diamond and David Landes
that factor endowments influence GDP per capita. However, Easterly and
Levine's findings most support the view that long-lasting institutions
most shape economic development outcomes. Relevant institutions include
private property rights and the rule of law.
Jeffrey B. Nugent and James A. Robinson similarly challenge scholars like Barrington Moore who hold that certain factor endowments and agricultural preconditions necessarily lead to particular political and economic organizations. Nugent and Robinson show that coffee economies in South America pursued radically different paths of political and economic development during the nineteenth century.
Some coffee states, like Costa Rica and Colombia, passed laws like the Homestead Act of 1862. They favored smallholders, held elections, maintained small militaries, and fought fewer wars. Smallholder arrangements prompted widespread government investment in education. Other states like El Salvador and Guatemala
produced coffee on plantations, where individuals were more
disenfranchised. Whether a state became a smallholder or plantation
state depended not on factor endowments but on norms established under colonialism—namely,
legal statutes determining access to land, the background of the
governing elites, and the degree of permitted political competition. Nugent and Robinson thereby conclude that factor endowments alone do not determine economic or political institutions.
Direct effects of geography on economic development
Effects of terrain on trade and productivity
Historians
have also noted population densities seem to concentrate on coastlines
and that states with large coasts benefit from higher average incomes
compared to those in landlocked countries. Coastal living has proven
advantageous for centuries as civilizations relied on the coastline and
waterways for trade, irrigation, and as a food source.
Conversely, countries without coastlines or navigable waterways are
often less urbanized and have less growth potential due to the slow
movement of knowledge capital, technological advances, and people. They
also have to rely on costly and time-consuming over-land trade, which
usually results in lack of access to regional and international markets,
further hindering growth. Additionally, interior locations tend to have
both lower population densities and labor-productivity levels. However,
factors including fertile soil, nearby rivers, and ecological systems
suited for rice or wheat cultivation can give way to dense inland
populations.
Nathan Nunn
and Diego Puga note that though rugged terrain usually makes farming
difficult, prevents travel, and limits societal growth, early African
states used harsh terrain to their advantage.
The authors used a terrain ruggedness index to quantify topographic
heterogeneity across several regions of Africa, while simultaneously
controlling for variables such as diamond availability and soil
fertility. The results suggest that historically, ruggedness is strongly
correlated with decreased income levels across the globe and has
negatively impacted state growth over time. They note that harsh terrain
limited the flow of trade goods and decreased crop availability, while
isolating communities from developing knowledge capital. However, the
study also demonstrated that the terrain had positive effects on some
African communities by protecting them from the slave trade. Communities
that were located in areas with rugged features could successfully hide
from slave traders and protect their homes from being destroyed. The
study found that in these areas rugged topography produced long-term
economic benefits and aided post-colonial state formation.
Effects of climate on productivity
The
impact that climate and water navigability have on economic growth and
GDP per capita was studied by notable scholars including Paul Krugman, Jared Diamond, and Jeffrey Sachs.
By using variables to measure environmental determinism, such as
climate, land composition, latitude, and the presence of infectious
disease, they account for trends in worldwide economic development on
local, regional and global scales. To do so, they measure economic
growth with GDP per capita adjusted to purchasing power parity (PPP),
while also taking into consideration population density and labor
productivity.
Economic historians have found that societies in the Northern Hemisphere
experience higher standards of living, and that as latitude increases
north or south from the equator, levels of real GDP per capita also
increases. Climate is closely correlated with agricultural production
since without ideal weather conditions, agriculture alone will not
produce the surplus supply needed to build and maintain economies.
Locations with hot tropical climates often suffer underdevelopment due
to low fertility of soils, excessive plant transpiration, ecological
conditions favoring infectious diseases, and unreliable water supply.
These factors can cause tropical zones to suffer a 30% to 50% decrease
in productivity relative to temperate climate zones.
Tropical infectious diseases that thrive in hot and moist equatorial
climates cause thousands of deaths each year. They are also an economic
drain on society due to high medical costs, and the unwillingness of
foreign capital to invest in a sickly state. Because infectious diseases
like malaria often need a warm ecology for growth, states in the mid to
high latitudes are naturally protected from the devastating effects of
disease.
Climatic determinism and colonization
Climatic determinism, otherwise referred to as the equatorial paradox, is an aspect of economic geography. According to this theory, about 70% of a country's economic development can be predicted by the distance between that country and the equator,
and that the further from the equator a country is located, the more
developed it tends to be. The theory is the central argument of Philip M. Parker's Physioeconomics: The Basis for Long-Run Economic Growth,
in which he argues that since humans originated as tropical mammals,
those who relocated to colder climates attempt to restore their
physiological homeostasis through wealth-creation. This act includes
producing more food, better housing, heating, warm clothes, etc.
Conversely, humans that remained in warmer climates are more
physiologically comfortable simply due to temperature, and so have less
incentive to work to increase their comfort levels. Therefore, according
to Parker GDP is a direct product of the natural compensation of humans to their climate.
Political geographers have used climatic determinism ideology to
attempt to predict and rationalize the history of civilization, as well
as to explain existing or perceived social and cultural divides between
peoples. Some argue that one of the first attempts geographers made to
define the development of human geography across the globe was to relate
a country's climate to human development. Using this ideology, many
geographers believed they were able "to explain and predict the progress
of human societies".
This led to warmer climate zones being "seen as producing less
civilized, more degenerate peoples, in need of salvation by western
colonial powers."
Ellsworth Huntington
also travelled continental Europe in hopes of better understanding the
connection between climate and state success, publishing his findings in
The Pulse of Asia, and further elaborating in Civilization and Climate.
Like the political geographers, a crucial component of his work was the
belief that the climate of North-western Europe was ideal, with areas
further north being too cold, and areas further south being too hot,
resulting in lazy, laid-back populations. These ideas were powerful connections to colonialism, and may have played a role in the creation of the 'other' and the literature that many used to justify taking advantage of less advanced nations.
Huntington also argued that climate can lead to the demise of even
advanced civilizations through drought, food insecurity, and damages to
economic production.
Race and health refers to how being identified with a specific race influences health. Race is a complex concept that has changed across chronological eras and depends on both self-identification and social recognition. In the study of race and health, scientists organize people in racial categories depending on different factors such as: phenotype, ancestry, social identity, genetic makeup and lived experience. "Race" and ethnicity often remain undifferentiated in health research.
Differences in health status, health outcomes, life expectancy, and many other indicators of health in different racial and ethnic groups are well documented. Epidemiological data indicate that racial groups are unequally affected by diseases, in terms or morbidity and mortality. Some individuals in certain racial groups receive less care, have less access to resources, and live shorter lives in general. Overall, racial health disparities appear to be rooted in social disadvantages associated with race such as implicit stereotyping and average differences in socioeconomic status.
Health disparities are defined as "preventable differences in the
burden of disease, injury, violence, or opportunities to achieve
optimal health that are experienced by socially disadvantaged
populations". According to the U.S. Centers for Disease Control and Prevention,
they are intrinsically related to the "historical and current unequal
distribution of social, political, economic and environmental
resources".
The relationship between race and health has been studied from multidisciplinary perspectives, with increasing focus on how racism influences health disparities, and how environmental and physiological factors respond to one another and to genetics.
Racial health disparities
Health disparities refer to gaps in the quality of health and health care across racial and ethnic groups. The US Health Resources and Services Administration
defines health disparities as "population-specific differences in the
presence of disease, health outcomes, or access to health care". Health is measured through variables such as life expectancy and incidence of diseases.
For racial and ethnic minorities in the United States, health
disparities take on many forms, including higher rates of chronic
disease, premature death, and maternal mortality
compared to the rates among whites. It is important to note that this
pattern is not universal. Some minority groups—most notably, Hispanic
immigrants—may have better health outcomes than whites when they arrive
in the United States. However this appears to diminish with time spent
in the United States.
For other indicators, disparities have shrunk, not because of
improvements among minorities but because of declines in the health of
majority groups.
In the U.S., more than 133 million Americans (45% of the
population) have one or more chronic diseases. One study has shown that
between the ages of 60 to 70, racial/ethnic minorities are 1.5 to 2.0
times more likely than whites (Hispanic and non Hispanic) to have one of
the four major chronic diseases specifically Diabetes, cancer,
cardiovascular disease (CVD), and chronic lung disease. However, the
greatest differences only occurred among people with single chronic
diseases. Racial/ethnic differences were less distinct for some
conditions including multiple diseases. Non-Hispanic whites trended
toward a high prevalence for dyads of cardiovascular disease (CVD) with
cancer or lung disease. Hispanics and African Americans had the greatest
prevalence of diabetes, while non-Hispanic blacks had higher odds of
having heart disease with cancer or chronic lung disease than
non-Hispanic whites. Among non-Hispanic whites the prevalence of multimorbidities
that include diabetes was low; however, non-Hispanic whites had a very
high prevalence of multimorbidities that exclude diabetes. Non-Hispanic
whites had the highest prevalence of cancer only or lung disease only.
Between 1960 and 2005 the percentage of children with a chronic
disease in the United States quadrupled with minority having higher
likelihood for these disease. The most common major chronic biases of
youth in the United States are asthma, diabetes mellitus, obesity, hypertension, dental disease, attention deficit hyperactivity disorder (ADHD), mental illness, cancers and others. This results in Black and Latinx
adult patients facing a disproportionate amount of health concerns,
such as asthma, with treatment and management guidelines not developed
with studies based on their populations and healthcare needs.
Although individuals from different environmental, continental,
socioeconomic, and racial groups etc. have different levels of health,
yet not all of these differences are always categorized or defined as
health disparities. Some researchers separate definitions of health inequality
from health disparity by preventability. Health inequalities are often
categorized as being unavoidable i.e. due to age, while preventable
unfair health outcomes are categorized as health inequities. These are
seen as preventable because they are usually associated with income,
education, race, ethnicity, gender, and more.
Definitions of race are ambiguous due to the various paradigms used
to discuss race. These definitions are a direct result of biological and
social views. Definitions have changed throughout history to yield a
modern understanding of race that is complex and fluid. Moreover, there
is no one definition that stands, as there are many competing and
interlocking ways to look at race.
Due to its ambiguity, terms such as race, genetic population,
ethnicity, geographic population, and ancestry are used interchangeably
in everyday discourse involving race. Some researchers critique this
interchangeability noting that the conceptual differences between race
and ethnicity are not widely agreed upon.
Even though there is a broad scientific agreement that essentialist and typological conceptions of race are untenable, scientists around the world continue to conceptualize race in widely differing ways.
Historically, biological definitions of race have encompassed both
essentialist and anti-essentialist views. Essentialists have sought to
show that racial groups are genetically distinct populations, describing
"races as groups of people who share certain innate, inherited
biological traits".
In contrast, anti-essentialists have used biological evidence to
demonstrate that "race groupings do not reflect patterns of human
biological variation, countering essentialist claims to the contrary".
Over the past 20 years, a consensus has emerged that, while race
is partially based on physical similarities within groups, it does not
have an inherent physical or biological meaning. In response, researchers and social scientists have begun examining notions of race as constructed.
Racial groups are "constructed" from differing historical, political,
and economic contexts, rather than corresponding to inherited,
biological variations. Proponents of the constructionist view claim that
biological definitions have been used to justify racism in the past and
still have the potential to be used to encourage racist thinking in the
future.
Since race is changing and often so loosely characterized on arbitrary
phenotypes, and because it has no genetic basis, the only working
definition we can assign it is a social construct. This is not to say
race is imaginary or non-existent. It is an important social reality.
However to say that the concept of race has any scientific merit or has a
scientific foundation can lead to many issues in scientific research,
and it may also lead to inherent racial bias.
Social views also better explain the ambiguity of racial
definitions. An individual may self-identify as one race based on one
set of determinants (for example, phenotype, culture, ancestry) while
society may ascribe the person otherwise based on external forces and
discrete racial standards. Dominant racial conceptions influence how
individuals label both themselves and others within society.
Modern human populations are becoming more difficult to define within
traditional racial boundaries due to racial admixture. Most scientific
studies, applications, and government documents ask individuals to
self-identify race from a limited assortment of common racial
categories.
The conflict between self-identification and societal ascription
further complicates biomedical research and public health policies.
However complex its sociological roots, race has real biological
ramifications; the intersection of race, science, and society permeates
everyday life and influences human health via genetics, access to
medical care, diagnosis, and treatment.
Race and disease
Diseases affect racial groups differently, especially when they are co-related with class disparities. As socioeconomic factors influence the access to care,
the barriers to access healthcare systems can perpetuate different
biological effects of diseases among racial groups that are not
pre-determined by biology.
Some researchers advocate for the use of self-reported race as a
way to trace socioeconomic disparities and its effects in health. For instance, a study conducted by the National Health Service
checks program in the United Kingdom, which aims to increase diagnosis
across demographics, noted that "the reported lower screening in
specific black and minority ethnic communities... may increase
inequalities in health."
In this specific case, the lack of attention to certain demographics
can be seen as a cause of increased instances of disease from this lack
of proper, equal preventive care. One must consider these external
factors when evaluating statistics on the prevalence of disease in
populations, even though genetic components can play a role in
predispositions to contracting some illnesses.
Individuals who share a similar genetic makeup can also share
certain propensity or resistance to specific diseases. However, there
are confronted positions in relation to the utility of using 'races' to
talk about populations sharing a similar genetic makeup. Some
geneticists argued that human variation is geographically structured and
that genetic differences correlate with general conceptualizations of
racial groups.
Others claimed that this correlation is too unstable and that the
genetic differences are minimal and they are "distributed over the world
in a discordant manner". Therefore, race is regarded by some as a useful tool for the assessment of genetic epidemiological risk, while others consider it can lead to an increased underdiagnosis in 'low risk' populations.
There are many autosomal recessive single gene genetic disorders that differ in frequency between different populations due to the region and ancestry as well as the founder effect. Some examples of these disorders include:
Sickle-cell anemia,
most prevalent in populations with sub-Saharan African ancestry but
also common among Latin-American, Middle Eastern populations, as well as
those people of South European regions such as Turkey, Greece, and
Italy
Thalassemia, most prevalent in populations having Mediterranean ancestry, to the point that the disease's name is derived from Greek thalasson, "sea"
Many
diseases differ in frequency between different populations. However,
complex diseases are affected by multiple factors, including genetic and
environmental. There is controversy over the extent to which some of
these conditions are influenced by genes, and ongoing research aims to
identify which genetic loci, if any, are linked to these diseases. "Risk
is the probability that an event will occur. In epidemiology, it is
most often used to express the probability that a particular outcome
will occur following a particular exposure."
Different populations are considered "high-risk" or "low-risk" groups
for various diseases due to the probability of that particular
population being more exposed to certain risk factors. Beyond genetic
factors, history and culture, as well as current environmental and
social conditions, influence a certain populations' risk for specific
diseases.
Disease progression
Racial
groups may differ in how a disease progresses. Different access to
healthcare services, different living and working conditions influence
how a disease progresses within racial groups.
However, the reasons for these differences are multiple, and should not
be understood a consequence of genetic differences between races, but
rather as effects of social and environmental factors affecting.
Prevention
Genetics
have been proven to be a strong predictor for common diseases such as
cancer, cardiovascular disease (CVD), diabetes, autoimmune disorders,
and psychiatric illnesses. Some geneticists have determined that "human genetic variation is geographically structured" and that different geographic regions correlate with different races. Meanwhile, others have claimed that the human genome is characterized by clinal changes across the globe, in relation with the "Out of Africa" theory and how migration to new environments cause changes in populations' genetics over time.
Some diseases are more prevalent in some populations identified
as races due to their common ancestry. Thus, people of African and
Mediterranean descent are found to be more susceptible to sickle-cell disease while cystic fibrosis and hemochromatosis are more common among European populations.
Some physicians claim that race can be used as a proxy for the risk
that the patient may be exposed to in relation to these diseases.
However, racial self-identification only provides fragmentary
information about the person's ancestry. Thus, racial profiling in
medical services would also lead to the risk of underdiagnosis.
While genetics certainly play a role in determining how
susceptible a person is to specific diseases, environmental, structural
and cultural factors play a large role as well.
For this reason, it is impossible to discern exactly what causes a
person to acquire a disease, but it is important to observe how all
these factors relate to each other. Each person's health is unique, as
they have different genetic compositions and life histories.
Racial groups, especially when defined as minorities or ethnic
groups, often face structural and cultural barriers to access healthcare
services. The development of culturally and structurally competent
services and research that meet the specific health care needs of racial
groups is still in its infancy. In the United States, the Office of Minority Health
The NIH (National institutes of health) and The WHO are organizations
that provide useful links and support research that is targeted at the
development of initiatives around minority communities and the health
disparities they face. Similarly, In the United Kingdom, the National Health Service established a specialist collection on Ethnicity & Health. This resource was supported by the National Institute for Health and Clinical Excellence (NICE) as part of the UK NHS Evidence initiative NHS Evidence.
Similarly, there are growing numbers of resource and research centers
which are seeking to provide this service for other national settings,
such as Multicultural Mental Health Australia. However, cultural competence has also been criticized for having the potential to create stereotypes.
Scientific studies have shown the lack of efficacy of adapting
pharmaceutical treatment to racial categories. "Race-based medicine" is
the term for medicines that are targeted at specific racial clusters
which are shown to have a propensity for a certain disorder. The first
example of this in the U.S. was when BiDil, a medication for congestive heart failure, was licensed specifically for use in American patients that self-identify as black.
Previous studies had shown that African American patients with
congestive heart failure generally respond less effectively to
traditional treatments than white patients with similar conditions.
After two trials, BiDil was licensed exclusively for use in
African American patients. Critics have argued that this particular
licensing was unwarranted, since the trials did not in fact show that
the drug was more effective in African Americans than in other groups,
but merely that it was more effective in African Americans than other
similar drugs. It was also only tested in African American males, but
not in any other racial groups or among women. This peculiar trial and
licensing procedure has prompted suggestions that the licensing was in
fact used as a race-based advertising scheme.
Critics are concerned that the trend of research on race-specific
pharmaceutical treatments will result in inequitable access to
pharmaceutical innovation and smaller minority groups may be ignored.
This has led to a call for regulatory approaches to be put in place to
ensure scientific validity of racial disparity in pharmacological
treatment.
An alternative to "race-based medicine" is personalized or precision medicine. Precision medicine is a medical model that proposes the customization of healthcare,
with medical decisions, treatments, practices, or products being
tailored to the individual patient. It involves identifying genetic,
genomic (i.e., genomic sequencing), and clinical information—as opposed
to using race as a proxy for these data—to better predict a patient's
predisposition to certain diseases.
A positive correlation between minorities and a socioeconomic status
of being low-income in industrialized and rural regions of the U.S.
depict how low-income communities tend to include more individuals that
have a lower educational background, most importantly in health.
Income status, diet, and education all construct a higher burden for
low-income minorities, to be conscious about their health. Research
conducted by medical departments at universities in San Diego, Miami,
Pennsylvania, and North Carolina suggested that minorities
in regions where lower socioeconomic status is common, there was a
direct relationship with unhealthy diets and greater distance of
supermarkets. Therefore, in areas where supermarkets are less accessible (food deserts) to impoverished areas, the more likely these groups are to purchase inexpensive fast food or just follow an unhealthy diet.
As a result, because food deserts are more prevalent in low income
communities, minorities that reside in these areas are more prone to obesity, which can lead to diseases such as chronic kidney disease, hypertension, or diabetes.
Furthermore, this can also occur when minorities living in rural areas undergoing urbanization, are introduced to fast food.
A study done in Thailand focused on urbanized metropolitan areas, the
students who participated in this study as were diagnosed as "non-obese"
in their early life according to their BMI, however were increasingly
at risk of developing Type 2 Diabetes, or obesity as adults, as opposed to young adults who lived in more rural areas during their early life.
Therefore, early exposure to urbanized regions can encourage unhealthy
eating due to widespread presence of inexpensive fast food. Different
racial populations that originate from more rural areas and then
immigrate to the urbanized metropolitan areas can develop a fixation for
a more westernized diet; this change in lifestyle typically occurs due
to loss of traditional values when adapting to a new environment. For
example, a 2009 study named CYKIDS was based on children from Cyprus,
a country east of the Mediterranean Sea, who were evaluated by the
KIDMED index to test their adherence to a Mediterranean diet after
changing from rural residence to an urban residence. It was found that children in urban areas swapped their traditional dietary patterns for a diet favoring fast food.
Genetic factors
The
fact that every human has a unique genetic code is the key to
techniques such as genetic fingerprinting. Versions of genetic markers,
known as alleles, occur at different frequencies in different human
populations; populations that are more geographically and ancestrally
remote tend to differ more.
A phenotype is the "outward, physical manifestation" of an organism."
For humans, phenotypic differences are most readily seen via skin
color, eye color, hair color, or height; however, any observable
structure, function, or behavior can be considered part of a phenotype. A
genotype is the "internally coded, inheritable information" carried by
all living organisms. The human genome is encoded in DNA.
For any trait of interest, observed differences among individuals
"may be due to differences in the genes" coding for a trait and "the
result of variation in environmental condition". This variability is due
to gene-environment interactions that influence genetic expression
patterns and trait heritability.
For humans, there is "more genetic variation among individual people than between larger racial groups".
In general, an average of 80% of genetic variation exists within local
populations, around 10% is between local populations within the same
continent, and approximately 8% of variation occurs between large groups
living on different continents.
Studies have found evidence of genetic differences between populations,
but the distribution of genetic variants within and among human
populations is impossible to describe succinctly because of the
difficulty of defining a "population", the clinal nature of variation,
and heterogeneity across the genome.
Thus, the racialization of science and medicine can lead to controversy
when the term population and race are used interchangeably.
Currently malaria-endemic countries in the eastern hemisphere
Currently malaria-endemic countries in the western hemisphere
Genes may be under strong selection in response to local diseases. For example, people who are duffy negative
tend to have higher resistance to malaria. Most Africans are duffy
negative and most non-Africans are duffy positive due to endemic
transmission of malaria in Africa. A number of genetic diseases more prevalent in malaria-affected areas may provide some genetic resistance to malaria including sickle cell disease, thalassaemias, glucose-6-phosphate dehydrogenase, and possibly others.
In earlier research, a common theory was the "common disease-common variant"
model. It argues that for common illnesses, the genetic contribution
comes from the additive or multiplicative effects of gene variants that
each one is common in the population. Each such gene variant is argued
to cause only a small risk of disease and no single variant is
sufficient or necessary to cause the disease. An individual must have
many of these common gene variants in order for the risk of disease to
be substantial.
More recent research indicates that the "common disease-rare
variant" may be a better explanation for many common diseases. In this
model, rare but higher-risk gene variants cause common diseases. This model may be relevant for diseases that reduces fertility.
In contrast, for common genes associated with common disease to persist
they must either have little effect during the reproductive period of
life (like Alzheimer's disease)
or provide some advantage in the original environment (like genes
causing autoimmune diseases also providing resistance against
infections). In either case varying frequencies of genes variants in
different populations may be an explanation for health disparities. Genetic variants associated with Alzheimer's disease, deep venous thrombosis, Crohn disease, and type 2 diabetes appear to adhere to "common disease-common variant" model.
Gene flow
Gene flow and admixture
can also have an effect on relationships between race and race-linked
disorders. Multiple sclerosis, for example, is typically associated with
people of European descent, but due to admixture African Americans have
elevated levels of the disorder relative to Africans.
Some diseases and physiological variables vary depending upon their admixture ratios. Examples include measures of insulin functioning and obesity.
Gene interactions
The
same gene variant, or group of gene variants, may produce different
effects in different populations depending on differences in the gene
variants, or groups of gene variants, they interact with. One example is
the rate of progression to AIDS and death in HIV–infected patients. In Caucasians and Hispanics, HHC haplotypes
were associated with disease retardation, particularly a delayed
progression to death, while for African Americans, possession of HHC
haplotypes was associated with disease acceleration. In contrast, while
the disease-retarding effects of the CCR2-641 allele were found in
African Americans, they were not found in Caucasians.
Theoretical approaches in addressing health and race disparities
Public
health researchers and policy makers are working to reduce health
disparities. Health effects of racism are now a major area of research.
In fact, these seem to be the primary research focus in biological and
social sciences.
Interdisciplinary methods have been used to address how race affects
health. according to published studies, many factors combine to affect
the health of individuals and communities.
Whether people are healthy or not, is determined by their circumstances
and environment. Factors that need to be addressed when looking at
health and race include income and social status, education, physical
environment, social support networks, genetics, health services,
targeted instruction, and gender. These determinants are often cited in public health, anthropology, and
other social science disciplines. The WHO categorizes these determinants
into three broader topics: the social and economic environment, the
physical environment, and the person's individual characteristics and
behaviors. Due to the diversity of factors that often attribute to
health disparities outcomes, interdisciplinary approaches are often
implemented.
Interdisciplinarity or interdisciplinary studies involves the combining of two or more academic disciplines into one activity (e.g., a research project) The term interdisciplinary
is applied within education and training pedagogies to describe studies
that use methods and insights of several established disciplines or
traditional fields of study. Interdisciplinarity involves researchers,
students, and teachers in the goals of connecting and integrating
several academic schools of thought, professions, or technologies—along
with their specific perspectives—in the pursuit of a common task.
Biocultural approach
Biocultural evolution was introduced and first used in the 1970s. Biocultural methods focus on the interactions between humans and their environment to understand human biological adaptation and variation. These studies:
"research on questions of human biology and medical ecology that
specifically includes social, cultural, or behavioral variables in the
research design, offer valuable models for studying the interface
between biological and cultural factors affecting human well-being"
This approach is useful in generating holistic viewpoints on
human biological variation. There are two biocultural approach models.
The first approach fuses biological, environmental, and cultural data.
The second approach treats biological data as primary data and culture
and environmental data as secondary.
The salt sensitivity hypothesis is an example of implementing
biocultural approaches in order to understand cardiovascular health
disparities among African American populations. This theory, founded by
Wilson and Grim, stems from the disproportional rates of salt sensitive
high blood pressure seen between U.S. African American and White
populations and between U.S. African American and West Africans as well.
The researchers hypothesized that the patterns were in response to two
events. One the trans-Atlantic slave trade, which resulted in massive
death totals of Africans who were forced over, those who survived and
made to the United States were more likely able to withstand the harsh
conditions because they retained salt and water better. The selection
continued once they were in the United States. African Americans who
were able to withstand hard working conditions had better survival rates
due to high water and salt retention. Second, today, because of
different environmental conditions and increased salt intake with diets,
water and salt retention are disadvantageous, leaving U.S. African
Americans at disproportional risks because of their biological descent
and culture.
Bio social inheritance model
Similar
to the biocultural approach, the bio social inheritance model also
looks at biological and social methods in examining health disparities.
Hoke et al. define Biosocial inheritance as "the process whereby social
adversity in one generation is transmitted to the next through
reinforcing biological and social mechanisms that impair health,
exacerbating social and health disparities."
There is a controversy regarding race as a method for classifying humans. Different sources argue it is purely social construct
or a biological reality reflecting average genetic group differences.
New interest in human biological variation has resulted in a resurgence
of the use of race in biomedicine.
The main impetus for this development is the possibility of improving the prevention and treatment of certain diseases
by predicting hard-to-ascertain factors, such as genetically
conditioned health factors, based on more easily ascertained
characteristics such as phenotype and racial self-identification. Since
medical judgment often involves decision making under uncertain
conditions,
many doctors consider it useful to take race into account when treating
disease because diseases and treatment responses tend to cluster by
geographic ancestry.
The discovery that more diseases than previously thought correlate with
racial identification have further sparked the interest in using race
as a proxy for bio-geographical ancestry and genetic buildup.
Race in medicine is used as an approximation for more specific
genetic and environmental risk factors. Race is thus partly a surrogate
for environmental factors such as differences in socioeconomic status
that are known to affect health. It is also an imperfect surrogate for
ancestral geographic regions and differences in gene frequencies between
different ancestral populations and thus differences in genes that can
affect health. This can give an approximation of probability for disease
or for preferred treatment, although the approximation is less than
perfect.
Taking the example of sickle-cell disease, in an emergency room,
knowing the geographic origin of a patient may help a doctor doing an
initial diagnosis if a patient presents with symptoms compatible with
this disease. This is unreliable evidence with the disease being present
in many different groups as noted above with the trait also present in
some Mediterranean European populations. Definitive diagnosis comes from
examining the blood of the patient. In the US, screening for sickle
cell anemia is done on all newborns regardless of race.
The continued use of racial categories has been criticized. Apart
from the general controversy regarding race, some argue that the
continued use of racial categories in health care and as risk factors
could result in increased stereotyping and discrimination in society and health services.
Some of those who are critical of race as a biological concept see race
as socially meaningful group that is important to study
epidemiologically in order to reduce disparities.
For example, some racial groups are less likely than others to receive
adequate treatment for osteoporosis, even after risk factors have been
assessed. Since the 19th century, blacks have been thought to have
thicker bones than whites have and to lose bone mass more slowly with
age.
In a recent study, African Americans were shown to be substantially
less likely to receive prescription osteoporosis medications than
Caucasians. Men were also significantly less likely to be treated
compared with women. This discrepancy may be due to physicians'
knowledge that, on average, African Americans are at lower risk for
osteoporosis than Caucasians. It may be possible that these physicians
generalize this data to high-risk African-Americans, leading them to
fail to appropriately assess and manage these individuals' osteoporosis.
On the other hand, some of those who are critical of race as a
biological concept see race as socially meaningful group that is
important to study epidemiologically in order to reduce disparities.
David Williams (1994) argued, after an examination of articles in the journal Health Services Research
during the 1966–90 period, that how race was determined and defined was
seldom described. At a minimum, researchers should describe if race was
assessed by self-report, proxy report, extraction from records, or
direct observation. Race was also often used questionable, such as an
indicator of socioeconomic status. Racial genetic explanations may be overemphasized, ignoring the interaction with and the role of the environment.
From concepts of race to ethnogenetic layering
There
is general agreement that a goal of health-related genetics should be
to move past the weak surrogate relationships of racial health disparity
and get to the root causes of health and disease. This includes
research which strives to analyze human genetic variation in smaller
groups than races across the world.
One such method is called ethnogenetic layering. It works by
focusing on geographically identified microethnic groups. For example,
in the Mississippi Delta region ethnogenetic layering might include such
microethnic groups as the Cajun
(as a subset of European Americans), the Creole and Black groups [with
African origins in Senegambia, Central Africa and Bight of Benin] (as a
subset of African Americans), and Choctaw, Houmas, Chickasaw, Coushatta,
Caddo, Atakapa, Karankawa and Chitimacha peoples (as subsets of Native
Americans).
Better still may be individual genetic assessment of relevant genes.
As genotyping and sequencing have become more accessible and
affordable, avenues for determining individual genetic makeup have
opened dramatically.
Even when such methods become commonly available, race will continue to
be important when looking at groups instead of individuals such as in
epidemiologic research.
Some doctors and scientists such as geneticist Neil Risch
argue that using self-identified race as a proxy for ancestry is
necessary to be able to get a sufficiently broad sample of different
ancestral populations, and in turn to be able to provide health care
that is tailored to the needs of minority groups.
One area in which population categories can be important
considerations in genetics research is in controlling for confounding
between population genetic substructure, environmental exposures, and
health outcomes. Association studies
can produce spurious results if cases and controls have differing
allele frequencies for genes that are not related to the disease being
studied, although the magnitude of its problem in genetic association studies is subject to debate. Various techniques detect and account for population substructure, but these methods can be difficult to apply in practice.
Population genetic substructure also can aid genetic association
studies. For example, populations that represent recent mixtures of
separated ancestral groups can exhibit longer-range linkage disequilibrium between susceptibility alleles and genetic markers than is the case for other populations. Genetic studies can use this disequilibrium to search for disease
alleles with fewer markers than would be needed otherwise. Association
studies also can take advantage of the contrasting experiences of racial
or ethnic groups, including migrant groups, to search for interactions
between particular alleles and environmental factors that might
influence health.
In a report by the Institute of Medicine
called Unequal Treatment, three major source categories are put forth
as potential explanations for disparities in health care: patient-level
variables, healthcare system-level factors, and care process-level
variables.
Patient-level variables
There
are many individual factors that could explain the established
differences in health care between different racial and ethnic groups.
First, attitudes and behaviors of minority patients are different. They
are more likely to refuse recommended services, adhere poorly to
treatment regimens, and delay seeking care, yet despite this, these
behaviors and attitudes are unlikely to explain the differences in
health care.
In addition to behaviors and attitudes, biological based racial
differences have been documented, but these also seem unlikely to
explain the majority of observed disparities in care.
Health system-level factors
Health
system-level factors include any aspects of health systems that can
have different effects on patient outcomes. Some of these factors
include different access to services, access to insurance or other means
to pay for services, access to adequate language and interpretation
services, and geographic availability of different services.
Many studies assert that these factors explain portions of the existing
disparities in health of racial and ethnic minorities in the United
States when compared to their white counterparts.
Care process-level variables
Three
major mechanisms are suggested by the Institute of Medicine that may
contribute to healthcare disparities from the provider's side: bias (or
prejudice) against racial and ethnic minorities; greater clinical
uncertainty when interacting with minority patients; and beliefs held by
the provider about the behavior or health of minorities.
While research in this area is ongoing, some exclusions within clinical
trials themselves are also present. A recent systematic review of the
literature relating to hearing loss in adults demonstrated that many
studies fail to include aspects of racial or ethnic diversity, resulting
in studies that do not necessarily represent the US population.
