Human Variation, Race, and Racism

Human Variation, Race, and Racism: A Biological and Social Perspective

Understanding Adaptation and Acclimatization

  • High Altitude Adaptation: This phenomenon, discussed by Professor Mendenhall, serves as a prime example of biological responses to environmental stressors.

    • Adaptation: Refers to changes in a population's genotype across multiple generations in response to environmental stressors. It's an evolutionary process.

    • Acclimatization: Refers to short-term, individual experiences of changes in a person's phenotype (observable characteristics) in response to their environment. This is not about changes to the genetic code itself but how existing genes are expressed or how the body reacts within a lifetime. For example, an individual moving to a high-altitude area might acclimatize by producing more red blood cells.

The Context of Human Variation

  • Evolution and Context: Understanding human variation requires context, especially when comparing humans to our closest genetic relatives.

  • The Complications of "Race": Historically, concepts about human variation have been inherited, leading to the idea of "race." Today, we understand race as a socially constructed concept that is not based on accurate biological observations.

    • We will distinguish between social constructs and biological realities.

  • Observations vs. Truth: Direct observations don't always reveal the full truth. One must critically examine what is being observed. For instance, superficial differences might be due to age rather than species variation.

Genetic Diversity: Chimpanzees vs. Humans

  • Chimpanzee Subspecies Example: To illustrate genetic diversity, consider the three subspecies of chimpanzees:

    • Pan troglodytes verus (Western chimpanzee)

    • Pan troglodytes troglodytes (Central African chimpanzee)

    • Pan troglodytes schweinfurthii (East African chimpanzee)

    • Scientific Naming Conventions: Genus is always capitalized (e.g., Pan), species and subspecies are not (e.g., troglodytes, verus), and all names are italicized.

    • Superficial Observations: While these subspecies might show facial or skin color differences, skin darkness can be a factor of age, not necessarily genetic variation between them.

  • Genetic Diversity within and between Chimpanzee Subspecies: There is more genetic diversity between these chimpanzee subspecies than within them.

    • Measuring Diversity: Genetic diversity is measured by the number of mutations or substitutions occurring at each locus (position) in the genetic sequence (e.g., variations in A, C, T, G bases).

    • A higher bar on a genetic diversity chart indicates greater diversity (N_{substitutions} per nucleotide).

    • When comparing specific genetic blocks, red indicates variation within a subspecies, while blue indicates variation between subspecies. For chimpanzees, blue (between) is generally higher.

  • Human Genetic Diversity: Using the same scale of substitutions per nucleotide, we compare human populations across geographic regions (e.g., Europe, Asia, Africa).

    • Key Finding: There is significantly more genetic variation within any given human population than between human geographic populations.

    • This is a stark contrast to common perceptions that biological differences are vast between populations.

  • Conclusion: Genetic evidence shows there are no subspecies of humans.

    • This has major repercussions for outdated concepts of human variation being biologically meaningful in a racial sense.

The Historical Construction of "Race" as a Social Category

  • Race as a Mutable Social Category: Racial classification systems were designed to categorize people into different biological groups based on the premise of distinct "races." This concept has been embraced and then rejected by science over time.

  • Historical Perspectives on Variation:

    • Ancient Cultures (e.g., 1200 BCE): Many cultures recognized differences among people but did not necessarily categorize them as inherently distinct biological types.

    • Greek Classical Thought (Aristotle): Introduced "essentialism" and hierarchical categories, such as the "Great Chain of Being." Differences were often cultural; e.g., "barbarians" were simply people who did not adhere to Roman customs, and could become "civilized." This was not seen as an immutable biological difference.

  • Influence of the Scientific Revolution: The Scientific Revolution emphasized observation and the scientific method.

    • Carl Linnaeus: The Swedish botanist classified all life hierarchically (genus, species, family, etc.), placing humans within this system in relation to other animals. Despite being a creationist, his documentation revealed interconnections across life.

    • Linnaeus also categorized human "races" based on color and behavior.

    • Disagreement: Subsequent taxonomists faced a significant problem: they could never agree on the number of human "types" or "races." This inconsistency began to highlight the arbitrary nature of such classifications.

  • Continuous Variation vs. Discrete Categories: When viewed out of context, portions of a spectrum (like skin color) can appear discrete.

    • European Expansion: Modern science, particularly the concept of "race," emerged during periods of European colonial expansion. Encounters between people from geographically distant areas (e.g., via sea travel) created a perception of stark differences that seemed sudden.

    • Gradual Change: In contrast, if one were to walk across continents in ancient times, they would observe only gradual, continuous changes in human phenotype, with no sharp boundaries.

  • Colonialism and "Othering": This period of violent colonial encounters fostered a context where "othering" people was beneficial to the colonizers.

    • This led to an association of physical differences with concepts of "better" or "worse," justifying exploitation and oppression.

    • Scientists often allowed their own biases to influence their interpretation of observations, ignoring how context shapes what they were seeing.

Scientific Racism and Its Profound Impact

  • Early "Scientific" Racism: Samuel Morton, an early American medical practitioner, studied skull traits and physical characteristics, erroneously associating them with intelligence, behaviors, values, and morals. This research was instrumental in shaping societal treatment of different populations and justifying their suppression.

  • Eugenics: A frightening outcome associated with these ideas was eugenics – the belief that society could be improved by "breeding better kinds of people."

    • Eugenics advocated for prohibiting certain populations from marrying or for sterilizing individuals deemed "undesirable" by society.

  • Race is Not a Biological Concept: Eventually, scientists critically examined the arguments, moving from simple observations to rigorous testing.

    • Franz Boas: An early anthropologist, demonstrated that variations in cranial shape and height were largely based on environmental factors (e.g., nutrition, upbringing) rather than fixed genetic traits.

    • Scientific Racism Today: Is recognized as deeply flawed, based on faulty assumptions about the complexity of human traits and simplistic associations between observations. It ignores the intricate interplay of genetics and environment.

  • Indefinable Categories: The inability of scientists to agree on the number of human races highlights its arbitrary nature. This is why many anthropologists dislike ticking boxes for "race" on census forms, as it oversimplifies how fluid and context-dependent racial classifications are.

  • Human Genetic Homogeneity: When human populations today are examined, there is continuous gene flow and interbreeding. No population is completely separate from another. Observable physical features that appear starkly contrasted are, in fact, continuous in our biology.

    • Humans share 99\% of their genetic makeup.

    • We are grouped into local populations, not biologically distinct "races."

    • The evolution of cultural transmission emphasizes differences, which are often more significant than biological variation within the human species.

  • Lieberman and Lewontin's Findings: In 1972, genetic research, notably by Leonard Lieberman and Richard Lewontin using 17 DNA markers, demonstrated that more genetic variation exists within human populations than between them.

    • This led to a statement in an early textbook edition (no longer present): "Our intuitions sometimes lead us astray… Our intuition that race is real is also an illusion." This emphasizes the difficulty in overcoming deeply ingrained intuitive beliefs.

Racism is Real and Has Real Impacts

  • Crucial Distinction: While biologically, race is not real, racism itself is real and has severe, measurable impacts.

  • Health Repercussions: Racism and prejudice significantly affect the health and well-being of individuals.

    • Institutional Racism: These impacts are often woven into institutions, sometimes unintentionally, when lack of attention to variation perpetuates negative outcomes.

    • Biological Pathways to Health: Chronic stress, often stemming from racism and classism, leads to elevated cortisol levels.

      • Cortisol Overload: Suppresses the immune system, leading to higher rates of sickness and adverse effects on physical and mental health over time. This is observed in various power dynamics, such as the stress a subordinate might experience from a superior's evaluation (e.g., "the way a boss rates a poor secretary").

  • Societal Manifestations and Impacts:

    • Race-based residential segregation.

    • School and occupational segregation.

    • Concentration of poverty.

    • Intergenerational wealth transfer issues.

    • Mass incarceration of specific groups.

    • Weak social safety nets.

    • These factors create social environments leading to very distinct and measurable biological pathways to health disparities.

  • Case Studies:

    • COVID-19 and Pulse Oximetry: Pulse oximeters, used to measure blood oxygen levels, shine light through the skin. They were found to be less accurate on individuals with darker skin tones because melanin interferes with light absorption. This was not a deliberate attempt to harm dark-skinned people but a byproduct of a lack of attention to human variation during the device's design and testing phase, leading to diagnostic failures and poorer health outcomes.

    • Maternal Mortality: Examples like Serena Williams or similar cases of Black women experiencing complications or death during childbirth are not biologically determined by their ancestry. Instead, they are caused by systemic health disparities and biases within healthcare systems that lead to different treatment and outcomes for different populations.