Dynamics of Human Biocultural Diversity

A Unified Approach

Elisa J. Sobo

• Éditeur: Routledge
• Année: 2020
• ISBN:
  9780429957949
• Édition: 2
• Sujet: Medicina
• Sous-sujet: Teoria, pratica e riferimenti medici

This lively text by leading medical anthropologist Elisa J. Sobo offers a unique, holistic approach to human diversity and rises to the challenge of truly integrating biology and culture. The inviting writing style and fascinating examples make important ideas from complexity theory and epigenetics accessible to students. In this second edition, the material has been updated to reflect changes in both the scientific and socio-cultural landscape, for example in relation to topics such as the microbiome and transgender. Readers learn to conceptualize human biology and culture concurrently—as an adaptive biocultural capacity that has helped to produce the rich range of human diversity seen today. With clearly structured topics, an extensive glossary and suggestions for further reading, this text makes a complex, interdisciplinary topic a joy to teach. Instructor resources include an extensive test bank and a study guide.

Part I

A Systems View of Human Adaptation

Conceptualizing biology and culture separately, as if each exists independently, may be convenient, but it dulls our understanding of who we are, how we work, and what our participation in the human enterprise accomplishes for us. Part I of this book lays the foundation for a comprehensive and unified understanding of our biocultural diversity—one that embraces the interdependence of biology and culture and all that they entail. Through Part I, readers learn to think holistically, and to see the world from a systems perspective. Part I also introduces students to ‘adaptation’: a complex process entailing multiple forms of feedback through which the theoretically separate domains of body, behavior, and environment work as one in effecting change.

Chapter by Chapter Overview

Chapter 1 cuts straight to the chase, describing the nature–nurture debate and then demonstrating how it is mistaken and misleading. Rejecting the dualist position, this chapter presents an alternative, unified approach grounded in ‘systems thinking.’ It explains and exemplifies the holistic viewpoint of anthropology, paying special attention to the concept of adaptation and the phenomenon of ‘emergence.’ We explore the concept of ‘complexity’ in relation to how it can inform our understanding of human nature.

Chapter 2 introduces evolutionary biology with a focus on genetic adaptation. After giving readers a good grasp of how genes and traits are passed on to the next generation, this chapter explains how natural selection at the population level works, and why certain forms of genetic variation are useful for a group’s transgenerational survival or reproductive success from generation to generation.

In Chapter 3, we learn that the environment plays a key role in the ways that genes are expressed to begin with. This chapter introduces the concept of developmental adjustment, distinguishing it from natural selection and using that as a jumping-off point for an exploration of how genes are switched on and off via epigenetic mechanisms—biochemical transactions that affect gene expression. Given the human body’s inherent plasticity, if exposed to divergent epigenome-altering events, even twins with identical genetic profiles can end up with surprisingly different physical characteristics. Information in this chapter keeps us questioning the relationship between nature (here, genes) and nurture (the environment, and all that it entails) while demonstrating how nature and nurture work together to shape a population’s traits—both within and between generations.

Chapter 4 defines the term culture with reference to its adaptive function. Our capacity for cultural adaptation—once it emerged—has been crucial to humanity’s survival. Culture’s evolutionary emergence is explored with reference to the synergistic interaction of our ancestors’ evolving capacities for motor skills, empathy, cooperation, imagination, and symbolic communication (for instance, through the language of ritual) as well in regard to tool use, control of fire, and cooking. ‘Cultural relativism’ and ‘ethnocentrism’ also are defined and discussed as contrasting standpoints for interpreting data.

In Chapter 5 we turn our attention to the spread and settlement of behaviorally modern humankind, which culture’s emergence made possible. We examine how human migration around the globe fostered diverse biocultural differences between human populations, as well as how subsequent mingling may have dimmed or intensified these. We question assumptions about the biology of ‘race’ and demonstrate how geography in general and geographic clines in particular (geographically specific trait gradients) provide a much better explanation for the biological differences found within our species than the erroneous idea of biological race ever has done or can do. That said, making geographic, ancestry-based distinctions between subpopulations in certain limited circumstances can be useful; this also is discussed.

Central Lessons of Part I

At the end of Part I of the book, readers will be well-versed in systems thinking and able to explain the value of taking a holistic point of view or of adopting a unified approach in exploring biocultural diversity. In addition, they will be able to discuss and explain, using examples, how and why various forms of biocultural diversity came about.

Part I does not ignore the importance of human behavior in the evolution of human variation. However, its overall focus is on geographic or habitat-based adaptations and physical differences amenable to materialist scientific study, such as red blood cell structure, height, and lactase levels. This provides readers with a concrete basis for truly understanding the concepts presented. In this, Part I fosters in readers a deep grasp of the basics; it does so to ensure success as we study the more abstract forms of biocultural diversity that we address later.

1

Anthropology and Complexity

This chapter prepares you to:

• Define biological determinism, discuss its shortcomings, and explain what people hope to accomplish when using it
• Describe anthropology with reference to holism (in contrast to reductionism) and the comparative method
• Define and differentiate ecosystems and complex adaptive systems, paying special attention to the concept of adaptation and the phenomenon of emergence
• Demonstrate how human groups may be studied as (and as part of larger) complex adaptive systems, focusing on adaptation and emergence

Why are we the way we are? Why are we all somewhat different? These may seem like straightforward questions, but they address two of the most important and complicated puzzles humans face—and their answers are neither singular nor simple. Begin to brainstorm about flavor preference, athletic ability, or intellectual capacity, for example, and you will find yourself awash in various biological and cultural explanations. Most people can be split into two camps here: one favoring biology and the other, culture. Which camp is right? Is it biology or is it the fact of having been raised in a particular culture that determines how we look, think, move, and feel?

Although most people, including most scholars, view biology and culture, or nature and nurture, as different, even opposing forces that work separately or against each other, the opposition is both clumsy and futile. Culture and biology are both part of a system in which multiple mutlidirectional feedback loops can lead to fantastic and unanticipated biocultural outcomes. This chapter aims to help readers really take hold of this idea by exploring what we know about systems, paying special attention to the concept of adaptation and the phenomenon of emergence in the process.

Where Did the Nature–Nurture Question Come From?

Biological versus Cultural Determinism

We are not the first to ask “Nature or nurture?” This question has many historical roots. For example, it was incorporated into scientific inquiry in the writing and work of Francis Galton, a productive and well-known nineteenth-century geographer, meteorologist, psychologist, and statistician. In 1869, Galton (cousin to Charles Darwin) asserted in his book Hereditary Genius that talent is physically inherited: genius simply runs in the family. Galton’s scholarly peers berated him for ignoring the role of upbringing, so he bolstered his claims with another book, English Men of Science: Their Nature and Nurture. Galton chose this title purposively, explaining in the book that it supplied “a convenient jingle of words,” nature and nurture giving the many elements that shape us “two distinct heads” (Ridley 2003, 71).

For Galton, nature was the more powerful head by far. In explaining all human characteristics as a result of nature (heredity or biology), Galton discredited the role played by upbringing (nurture, culture), diverting attention from ‘nonbiological’ causes of human diversity.

We know that biological determinism—the argument that biology determines utterly and completely one’s capacities and characteristics—has problems. Calling certain arrangements ‘natural’ is a way to rationalize them rhetorically. It downplays, for instance, the vast amounts of hard work and sacrifice that records show really are put in by winning athletes such as Venus and Serena Williams, musical superstars such as Ludwig van Beethoven, and intellectual giants such as Albert Einstein. Positioning their achievements as resulting from inborn ‘gifts’—calling them ‘natural’—provides a self-serving excuse for the rest of us not to practice, drill, or work out. It diverts us from reaching our full developmental potential (Shenk 2011).

This does not seem so tragic when we think about it on the level of the individual or when the skills in question are rarefied. Yes, it is too bad that I am not the excellent soccer player or gold-medal swimmer (and so forth) that I could have been because I avoided dedicated training. However, when applied at the population level, biological determinism that leads people to place false limitations on their potential also can obstruct a group’s progress or productivity. Worse, those in power can use biological determinism strategically, to justify their advantages and keep others oppressed.

If the genius it takes to fix cars, say, is hereditary in males but not females, then barring girls and women from auto shop classes can be seen as justifiable: to let them in would be futile and waste resources. Similarly, the poor might be kept from being educated based on an argument that they are inherently dim-witted. Certainly, there would be no need to examine underfunding in inner-city schools as a possible source of low achievement rates if those low rates were written off as due to biology. My examples may seem extreme but they represent real situations, present and past (see Figure 1.1). Biological determinism has even justified the enslavement of one race by another as part of the so-called natural order.

FIGURE 1.1 “Colored entrance” of a cinema in Belzoni, Mississippi, c. 1939. Photo by Marion Post Wolcott, Library of Congress Prints and Photographs Division, LC-DIG-ppmsca-12888.

We know today, of course, that racist thinking has no scientific basis (see Chapter 5). The myth of ‘giftedness’ also has been debunked (Shenk 2011). Yet, biological determinism still haunts us—not only in the way it remains in use for justifying inequality but also in its antithesis or counter-form, cultural determinism. Cultural determinism argues that culture (rather than biology) determines one’s capacities and characteristics. Early twentieth-century anthropologists in the United States, appalled by racism, popularized this position. It may have its appeal, but it, too, is one-sided. It, too, exists, in a way, as an outcome of Galton’s “convenient jingle of words”: with respect to our original questions—Why are we the way we are? Why are we all somewhat different?—Galton and his followers have led us to believe that the answer must be either nature or nurture, not both (see Ridley 2003). However, the forced choice approach is in error.

Nature and Nurture Work Together

Recent advances in philosophy and science demonstrate that determinism of either kind is wrong-headed. Rather than asking if nature or nurture is in charge, we should ask how the two forces work together, inseparably in a system, to produce the vast and wondrous diversity of human experience. Humans are neither simply biological nor simply cultural; we are both.

To think otherwise is in some ways an artifact of language: separate terms label each of these facets of human existence, suggesting they are mutually exclusive. Any attempt to talk about them as blended ends up resorting to the inserted ‘and’ or, more efficiently, use of a silently hyphenated term, ‘biocultural.’ The assumption, even here, is that biology plus culture (or nature plus nurture) equals human experience; the two still are separate because of the additive characteristic of any compound phrase or word.

Nevertheless, with some effort, it is possible to get past this language barrier conceptually. Indeed, doing so—characterizing...