Modern Human Diversity: Race and Racism

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Chapter 12

• Modern Human Diversity Race and Racism

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Chapter Preview

• What Is the History of Human Classification?
• Is the Biological Concept of Race Useful for
  Studying Physical Variation in the Human Species?
• Is studying differences in Intelligence Among
  Populations Valid?
• What are the cause of Physical Variability?

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• What Is the History of Human Classification?

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The History of Human Classification

• European scholars of the 18th through early 20th
  centuries classified humans into a series of
  subspecies based on geography and features such
  as skin color, body size, head shape, and hair
  texture.
• Some scholars went a step further and placed
  these types into a hierarchical framework in
  which the white race was considered superior to
  other races racism.

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The History of The Race Concept

• Race refers to subspecies, and no subspecies
  exist within modern Homo sapiens.
• In the past, phenotypic differences - skin color,
  body size, head shape, and hair texture were
  used to identify different races
• Anthropologists have worked to expose the fallacy
  of race as a biological concept while recognizing
  the existence of race as a social construct.

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Biased Research

• The work of 19th-century Philadelphia physician
  Samuel Morton is an example of biased research
  conducted to justify prejudices.
• He measured a series of skulls to demonstrate
  the supposed biological superiority of groups of
  people through features of skull shape and size.

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• Is the Biological Concept of Race Useful for
  Studying Physical Variation in the Human Species?

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The Race Concept in Biology

• In biology, a population of a species that
  differs in the frequency of the variants of some
  gene or genes from other populations of the same
  species.

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Factors in the Biological Definition of Race

• It is arbitrary there is no agreement on how
  many differences it takes to make a race.
• Any one race does not have exclusive possession
  of any particular variant of any gene or genes.
• Populations are genetically open, meaning that
  genes flow between them and no fixed racial
  groups exist.
• The differences among individuals and within a
  population are generally greater than the
  differences among populations.

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Dermatoglyphics Fingerprint Patterns

• Fingerprint patterns of loops, whorls, and
  arches are genetically determined. Grouping
  people on this basis would place most Europeans,
  sub-Saharan Africans, and East Asians together as
  loops, Australian aborigines and the people of
  Mongolia together as whorls, and central
  Europeans and the Bushmen of southern Africa
  together as arches.

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Racial Variation

• Yao Ming, center for the Houston Rockets,
  receives his Special Olympics Global Ambassador
  jersey from athlete Xu Chuang (left) and Special
  Olympics East Asia President Dicken Yung.
• Standing side-by-side, these three individuals
  illustrate the wide range of variation seen
  within a single so-called racial category.

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The Concept Of Human Races

• While the biological race concept is not
  applicable to human variation, race exists as a
  cultural category.
• The confusion of social with biological factors
  is frequently combined with prejudices that then
  serve to exclude whole categories of people from
  certain roles or positions in society.
• Anthropologists have abandoned the race concept
  as being of no particular utility in
  understanding human biological variation.

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Persecution and Racial Identity

• Conflict in Darfur between the Janjaweed, a
  militia group recruited from local Arab tribes,
  and the non-Arab peoples of the region is a major
  humanitarian crisis.
• The number of internally displaced persons in
  Darfur was estimated to be 1.65 million, with an
  additional 200,000 refugees from Darfur fleeing
  to Chad.

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Racism

• A doctrine of racial superiority by which one
  group asserts its superiority over another.
• Racist individuals react on the basis of social
  stereotypes instead of scientific facts.
• Behavioral characteristics attributed to race can
  be explained with culture rather than biology.

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• Is studying differences in Intelligence Among
  Populations Valid?

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Race and Intelligence

• A question often asked by those unfamiliar with
  the fallacy of biological race in humans is
  whether some races are inherently more
  intelligent than others.
• But, what do we mean by the term intelligence?

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What is Intelligence?

• Most psychologists consider intelligence to be
  the product of the interaction of different sorts
  of cognitive abilities verbal,
  mathematical-logical, spatial, linguistic,
  musical, bodily kinesthetic, social, and
  personal.
• Each may be thought of as a particular kind of
  intelligence, unrelated to the others.

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Intelligence and IQ

• some psychologists insist that intelligence is a
  single quantifiable thing measured by IQ tests
• IQ tests measure performance (something that one
  does) rather than genetic disposition (something
  that the individual was born with). Performance
  on the test reflects past experiences and present
  motivational state, as well as innate ability

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Intelligence and IQ

• The tests do not measure intelligence per se, but
  the ability, conditioned by culture, of certain
  individuals to respond appropriately to certain
  questions conceived by Americans of European
  descent for comparable middle-class whites.

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The Bell Curve Controversy

• Herrnstein and Murray argued that the difference
  in IQ scores between Americans of African, Asian,
  and European descent is primarily determined by
  genetic factors and is therefore immutable.

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The Bell Curve Controversy

• They were criticized for
• violating basic rules of statistics
• utilizing studies, no matter how flawed, that
  appear to support their thesis while ignoring or
  barely mentioning those that contradict it
• Ignoring the fact that genes are inherited
  independently of one another such that the
  alleles associated with intelligence bear no
  relationship with the ones for skin pigmentation
  or with any other aspect of human variation such
  as blood type

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General Flaws in Studies of Intelligence

• Studies attempting to document biological
  differences generally involve comparisons among
  racesa category that for humans is biologically
  false.
• Cultures vary in terms of aspects of
  intelligence.
• Most tests used to measure intelligence are
  biased toward the dominant culture.
• Intelligence cannot be linked to evolutionary
  forces acting in a particular environment.

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• What are the cause of Physical Variability?

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Human Biological Diversity

• Physical variability is a product of genetic
  variation as it is expressed in a particular
  environment.
• Some physical traits are controlled by single
  genes, with variation present in alternate forms
  of the gene (alleles).
• Physical characteristics are controlled by
  multiple genes and are thus expressed
  continuously.
• Because evolutionary forces act on each physical
  trait independently, human biological variation
  can be studied only one trait at a time.

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Human Biological Diversity

• The physical characteristics of populations and
  individuals are a product of the interaction
  between genes and environments.
• Genes predispose people to a particular skin
  color, but an individuals skin color is also
  influenced by cultural and environmental factors.

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Human Biological Diversity

• Polymorphic traits used to describe species
  with alternative forms (alleles) of particular
  genes
• Polytypic traits the expression of genetic
  variants in different frequencies in different
  populations of a species

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Human Biological Diversity

• For characteristics controlled by a single gene
  (polymorphic), different versions of that gene,
  known as alleles, mediate variation.
• Example Blood type may appear in any of four
  distinct phenotypic forms (A, B, O, and AB).
• When polymorphisms of a species are distributed
  into geographically dispersed populations,
  biologists describe this species as polytypic
  (many types).
• Example In the distribution of the polymorphism
  for blood type, the human species is polytypic.

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Clines

• Anthropologists study biological diversity in
  terms of clines, or the continuous gradation over
  space in the form or frequency of a trait.
• The Clinal analysis of a continuous trait such as
  body shape, which is controlled by a series of
  genes, allows anthropologists to interpret human
  global variation in body build as an adaptation
  to climate.

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Clines and the Frequency of Type B Blood in Europe
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Epicanthic Eye Fold

• The epicanthic eye fold is common among people
  native to East Asia.
• While some anthropologists have suggested that
  this feature might be an adaptation to cold,
  genetic drift could also be responsible for the
  frequency of this trait among people of East Asia.

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Lactose Intolerance

• Example of culture acting as an agent of
  biological selection.
• The ability to digest lactose, the primary
  constituent of fresh milk, depends on the
  capacity to make the lactase enzyme.

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Lactose Intolerance

• A high retention of lactase (an enzyme in the
  small intestine that enables humans to assimilate
  lactose) is found in populations with a long
  tradition of dairying
• 10- 30 of Americans of African descent and
  0-30 of adult Asians are lactose tolerant.
• Lactose tolerance are normal for 80 of adults of
  northern European descent.

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Thrifty Genotype

• Permits efficient storage of fat to draw on in
  times of food shortage.
• In times of scarcity individuals with the thrifty
  genotype conserve glucose for use in brain and
  red blood cells.
• Regular access to glucose through the lactose in
  milk led to selection for the non-thrifty
  genotype as protection against adult-onset
  diabetes.

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Thrifty Genotype

• Populations that are lactose intolerant retain
  the thrifty genotype.
• When they are introduced to Western diets, the
  incidence of obesity and diabetes skyrockets.

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Skin Color A Case Study in Adaptation

• Skin color is subject to great variation and is
  attributed to several key factors
• the transparency or thickness of the skin
• a copper-colored pigment called carotene
• reflected color from the blood vessels
• the amount of melanin , a dark pigment, in the
  skins outer layer

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Factors in Variation of Skin Color

• Exposure to sunlight increases the amount of
  melanin, darkening the skin.
• Selective mating, as well as geographic location,
  plays a part in skin color distribution.

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Distribution of Human Skin Pigmentation before
1492
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Skin Color and Human Evolution

• How long did it take for light pigmentation to
  develop in populations living outside the
  tropics?
• We can use the settlement of Greater Australia
  60,000 ya to examine this question.

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Skin Color and Human Evolution

• The first Australians came from tropical
  Southeast Asia, spreading throughout Australia
  eventually to what is now the island of Tasmania,
  with a latitude and levels of ultraviolet
  radiation similar to New York City, Rome, or
  Beijing.
• As aboriginal Australians originally came from
  the tropics, we would expect them to have had
  darkly pigmented skin.

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Skin Color and Human Evolution

• In Australia, those populations that spread south
  of the tropics (where, as in northern latitudes,
  ultraviolet radiation is less intense) underwent
  some reduction of pigmentation but their skin
  color is still far darker than that of Europeans
  or East Asians.

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Skin Color and Human Evolution

• Therefore, it seems that it takes more than
  60,000 years to produce significant
  depigmentation.
• It may also be that Europeans and East Asians
  may have lived outside the tropics for far longer
  than the people of Tasmania or that settlement in
  latitudes even more distant from the equator were
  required for depigmentation to occur.