Human Nature and the Evolution of Society

Stephen K. Sanderson

• Publisher: Routledge
• Year: 2018
• ISBN:
  9780429979590
• Edition: 1
• Topic: Social Sciences
• Subtopic: Sociology
• Index: Social Sciences

If evolution has changed humans physically, has it also affected human behavior? Drawing on evolutionary psychology, sociobiology, and human behavioral ecology, Human Nature and the Evolution of Society explores the evolutionary dynamics underlying social life.

In this introduction to human behavior and the organization of social life, Stephen K. Sanderson discusses traditional subjects like mating behavior, kinship, parenthood, status-seeking, and violence, as well as important topics seldom included in books of this type, especially gender, economies, politics, foodways, race and ethnicity, and the arts. Examples and research on a wide range of human societies, both industrial and nonindustrial, are integrated throughout. With chapter summaries of key points, thoughtful discussion questions, and important terms defined within the text, the result is a broad-ranging and comprehensive consideration of human society, thoroughly grounded in an evolutionary perspective.

1

Theoretical Foundations

Darwinian Social Science Redux

Anthropologists and sociologists have spent about a century and a half trying to figure out the principles governing the operation of human society. Success has been rather modest, especially when compared to our bigger cousins in the physical and natural sciences, but some progress has nonetheless been made. There are several reasons why progress has not been greater, but one stands out above all the others: the failure to take seriously the notion that there is such a thing as human nature and that this nature plays a major role in human action. Anthropologists and sociologists have for many decades operated under one or another version of what has come to be called the Standard Social Science Model,* or SSSM.¹ This model assumes that behavior is determined almost entirely by various features of the social and cultural environment. Actually, the SSSM is a broad umbrella term encompassing a variety of approaches that vary in some of their details. The best known version of the SSSM was set forth early in the twentieth century by the anthropologist Franz Boas and has been carried forward by anthropologists and sociologists down to the present day.² The idea is that what separates humans from all other animals is culture, or the sum total of learned traditions, beliefs, values, and norms that people have created and acquired as members of a particular society. Culture was made possible by the evolution of the large and highly complex human brain, but once the capacity for culture emerged culture overrode human biology as the principal determinant of human behavior and social life.

Other versions of the SSSM include what might be called role theory and, more recently, social constructionism. Beginning in the 1930s the celebrated sociologist Talcott Parsons formulated the idea that social roles were central elements of social life.³ Roles were scripts designed by society that prescribed certain courses of action as appropriate or inappropriate. Through a process of socialization—direct teaching of juniors by their elders, as well as imitation of elders by juniors—people learned what was expected of them and acted accordingly. (Or, if they failed to act accordingly, they were subjected to sanctions designed to bring them back into line.) This kind of perspective gained wide traction in sociology and is still a major theme even today. Social constructionism is a reaction against what are called essentialist explanations of behavior. These are explanations that rely on the idea that certain social categories, such as gender or race, have “essential” characteristics that make them what they are. Essential characteristics are those that are a kind of defining essence of a category. For social constructionists, there are no defining essences. Social categories are cultural inventions or “constructions” created by particular groups of people at particular times. For the constructionists, an essence would be a type of biological essence, and this they reject emphatically. Social constructionism is probably the one version of the SSSM that denies the importance of human biology completely.

Things were not always this way. In the early years of social science, the late nineteenth and early twentieth centuries, a Darwinian evolutionary perspective was often employed. In sociology the leading Darwinian was a Finn by the name of Edward Westermarck. Westermarck wrote a series of books, the most important of which were a fat three-volume work on the history of human marriage and an equally fat two-volume work on the origin of the human moral sense.⁴ Westermarck’s contemporaries considered him to be one of the leading sociologists of the day and, indeed, we now know that he was far, far ahead of his time. Unfortunately, Westermarck’s star began to fade in the 1920s, and by the time of his death in 1939 his ideas had passed out of favor. The reason is that the tide had turned against Darwinian social science, with its emphasis on an evolved human nature, and sharply toward social and cultural explanations. Darwinism became a dead letter in social science for half a century, and the SSSM stole the show. If such a thing as a biologically determined human nature even existed, social scientists thought, it had to be of minor importance.

Why did things change in this way? The intellectual historian Carl Degler has argued persuasively that the reason was not new research or the discovery of new facts.⁵ At this time there was a great debate between “hereditarians” and “environmentalists.” Existing research could have been interpreted in a convincing way from either perspective. The most defensible interpretation would have emphasized the complex interplay of the genetic or biological and the social or cultural. And, indeed, some scholars drew this conclusion. Degler contends that the tide turned because of a new emerging ideology and social philosophy of egalitarianism. A new emphasis was being placed on social equality, and the new egalitarians fervently promoted this goal. Even some hereditarians got swept up in the tide and changed sides. Emphasis on heredity and individual differences, it was thought, undermined the quest for equality, whereas an emphasis on the role of the social and cultural environment promoted it. And thus the SSSM prevailed.

Nevertheless, important developments in theoretical biology in the 1960s and 1970s, especially in evolutionary biology, provided a basis for reconsidering biology’s relevance for human behavior. Major theoretical innovations by such eminent scholars as William Hamilton, Robert Trivers, and John Maynard Smith laid new foundations for the study of animal behavior, and human applications were quickly envisioned.⁶ As a result, Darwinism reawakened in social science in the 1970s and 1980s, being revived by people calling themselves sociobiologists or evolutionary psychologists.⁷ As Westermarck had done three-quarters of a century earlier, they used as their starting point the Darwinian theory of evolution by natural selection to understand the most fundamental features of human social behavior and social organization. This has led to a quantum leap in our understanding of how human social life works.

Darwinian Foundations

Before outlining the basic assumptions and principles of the new Darwinian social science, we first need to understand their general Darwinian foundations. Charles Darwin wrote his great book, On the Origin of Species, in 1859. His ideas have been modified and updated over the past century and a half, but most of the core ideas remain intact. He was not the first to introduce the idea of evolution as a way of explaining the wide diversity of species, but he introduced the mechanism that could explain how the evolutionary process worked. This mechanism is known as natural selection, and it is one of the simplest processes in nature. Here is how it works. In any population of organisms there are always more offspring produced than there are resources to support. Not all can survive and prosper. A “struggle for existence” is therefore going on all of the time, and organisms are unequally endowed for success in this struggle. Those organisms that have the characteristics that are most useful in adapting to a particular environment will have both a survival and a reproductive advantage. Being more likely to survive, they are also more likely to reproduce and thus leave copies of their genes in future generations. (Darwin didn’t know about genes, the science of genetics not yet having been developed, but he knew that organisms had traits that were passed on through reproduction, and that this was very important.)

Evolution by natural selection is a two-step process. It starts with variation, which we today know as genetic variation. There is always variation within any population of organisms. This variation arises through both genetic recombination (sexual reproduction) and, most importantly, through mutations, or small changes in single genes. Mutations provide the raw material essential for evolution to occur. Most mutations are harmful and often lethal. They may kill the organism outright, or prevent it from surviving to reproductive age. Some mutations are neutral in their effects, and a few are beneficial, which means that they contribute to survival and reproduction.

The second step is a selection process in which beneficial genes are favored and harmful genes are disfavored. Organisms with beneficial mutations are more likely than those with harmful mutations to survive and reproduce, and thus to pass their beneficial mutations to offspring, who in turn pass them along to their offspring, and so on. Harmful mutations get weeded out as a result of the earlier death and low reproductive rates of organisms containing them. Over very long periods of time, the large-scale accumulation of beneficial or favorable mutations produces changes in populations of organisms, and it is these changes that we call evolution.

Because the mechanism by which evolution occurs is natural selection, it is “nature” that is doing the selecting. By nature we mean the environments in which organisms live. Darwin and modern-day evolutionists have stressed that natural selection is an adaptive process, or one that fits organisms to their environments. Let’s take a simple example. Imagine a species of organisms called wuzzies, small mammals which have fur that is rather thin. Imagine also that the warm environment in which the wuzzies have been living has been getting colder and that the wuzzies do not have enough fur to protect them from the changing conditions. They start to die off. But a genetic mutation for thicker fur happens to arise in one of the wuzzies, and this mutation gives it a survival and reproductive advantage. It is a beneficial mutation. This wuzzy mates and passes its beneficial mutant gene along to the next generation. Many of its furrier offspring have the same advantage with the same reproductive results. Eventually, thin-furred wuzzies are replaced by thick-furred wuzzies. This is an evolutionary event, but on a rather small scale. Over millions or tens of millions of years much more evolution is possible. The evolving wuzzies may eventually give rise to new species, much like themselves in some ways but also distinct.

For natural selection to occur, organisms must do more than survive. They must also reproduce. This is the only way copies of their genes can remain in the gene pool and be passed along to descendants. An organism’s success, or fitness, is measured in terms of its degree of reproductive success. The fittest organisms are those that leave the most offspring and thus the greatest number of genes in future generations. This is the precise meaning of fitness, and in fact is the only meaning of fitness. In evolutionary terms, fitness cannot be measured or assessed in any other way.

A variation on the concept of fitness known as inclusive fitness was developed in the 1960s and 1970s.⁸ You can measure any organism’s inclusive fitness by counting its number of descendents, but you can also do it by enumerating its relatives in the same generation. Parents share half of their genes with offspring, but these offspring also share half of their genes with each other. Therefore, it came to be recognized that an organism can promote its genetic representation in a population by showing favoritism toward siblings, and also to some extent toward cousins. You can promote your inclusive fitness by producing offspring, but if you have brothers and sisters you can also do it by helping them reproduce. Favoring kin in this way is often called kin selection. The sum total of the copies of your genes in present and descendant generations is your inclusive fitness. It is this idea of inclusive fitness that became the conceptual foundation of what was to be called sociobiology and later evolutionary psychology.

Virtually all anthropologists and sociologists readily agree that evolution has occurred, and that natural selection is the principal mechanism responsible for it.⁹ They do not doubt that it is this process that produced humans from their prehuman ancestors. But most balk at the claim that natural selection applies to human behavior as well as to human anatomy and physiology. They say no, it doesn’t apply to behavior. But this book says yes. You are not being asked to accept this on faith, and evidence will be provided to support this claim. But that will take time and thus has to be postponed to later discussions. Indeed, that is mostly what this book is about.

If human behavior evolved just as the human body did, and if evolution is an adaptive process, then it stands to reason that many features of human behavior must be adaptive. As mentioned previously, this means that there must be something called human nature, which is the sum total of these adaptive behavioral tendencies. (More precisely, human nature is the sum total of the brain mechanisms that, in interaction with environmental contingencies, generate adaptive behaviors.) From a Darwinian point of view, the task is therefore to figure out what this human nature is like and how it evolved. What is inside the organism that drives its behavior? In this book we will figure that out and apply it to understand how people throughout the world behave and how societies work.

Sociobiology and Evolutionary Psychology

The term sociobiology came into general use in 1975 when the Harvard University biologist Edward O. Wilson published a huge book entitled Sociobiology: The New Synthesis.¹⁰ Most of it was about animal behavior, but the final chapter was about humans. Some social scientists paid close attention to that chapter and began to use some of its ideas. A decade later several anthropologists and psychologists started to think in Darwinian terms and introduced a very similar approach that they called evolutionary psychology. In the most general sense, sociobiologists and evolutionary psychologists seek to understand the biological foundations of human behavior and social life. More precisely, they argue that the human brain evolved to adapt itself to both the challenges of nature and the challenges imposed by interacting with other people. Humans’ evolved species-specific nature interacted with the natural and social environments to shape particular social behaviors and modes of social life.

Some say that evolutionary psychology is basically just a new name for sociobiology. E. O. Wilson, for example, has said that they are the same thing. Evolutionary psychologists see it differently, sometimes very differently. But first we need to consider where the representatives of the two approaches agree. Both agree that human nature evolved in what is called the Environment of Evolutionary Adaptedness (EEA), more often called the ancestral environment. This is the environment that existed prior to 10,000 years ago when humans everywhere subsisted by hunting and gathering and most often lived in relatively small bands or camps. Both approaches also agree that human nature evolved as a package of traits that were adaptive in solving the most important problems of human living. Human nature, in other words, consists of a package of evolutionary adaptations. In Darwinian terms, a trait is an evolutionary adaptation if it directs behavior that promotes the survival and reproductive success of any organism with the trait.

As for the differences, there are two principal bones of contention. Although agreeing with the evolutionary psychologists that human nature evolved in the ancestral environment, sociobiologists generally assume that what was adaptive back then continues to be adaptive today despite major changes in the nature of social life. Sociobiologists try to infer...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Preface
• Notes on Dating
• 1 Theoretical Foundations
• 2 Beginnings
• 3 Getting a Living
• 4 Foodways
• 5 Finding Mates
• 6 Family and Marriage
• 7 Parenthood
• 8 Gender
• 9 Status and Wealth
• 10 Power and Politics
• 11 Violence
• 12 Race and Ethnicity
• 13 Religion
• 14 Arts
• Epilogue: Evolution and Existence
• Bibliography
• Technical Terms
• Index