The Evolution of Culture

If any one thing distinguishes human beings from other species, it is culture—not in the sense of better-educated or high-brow, but culture in the sense of everyday customs shared and passed on by a group of people. The world contains such a diversity of cultures that for a time anthropologists who studied culture concentrated simply on classifying and cataloging human cultures according to their main characteristics, because they saw no scientific way to account for the diversity. That situation changed in the 1970s as psychologists and evolutionary biologists extended their explanations of behavior to include culture.

Since these explanations focused on behavior, one result of the biologists' and psychologists' influence was to redefine culture in terms of behavior. Before the 1970s, most anthropologists defined culture in terms of abstractions (mentalistic concepts) such as a set of shared attitudes, ideas, and beliefs. One notable exception was Marvin Harris, who defined culture more concretely as composed of shared customs (behavior). Skinner (1971), like Harris, defined culture concretely by pointing to the practices, both verbal and nonverbal, that a group of people might share.

Not only are customs diverse the world over, but also customs within any group can change drastically over time. If an American of today were transported back to colonial days, the modern would have difficulty talking with the colonists because spoken English has changed so much in the past 300 years. Misunderstandings would arise about dress and social behavior, marriage, sex, and property. According to historian C. J. Sommerville (1982), for example, childhood is a relatively recent invention, originating in the sixteenth century. Children's birthdays have only been celebrated regularly since the seventeenth century.

In evolutionary theory, the problem of accounting for diversity of forms coincides with the problem of explaining change, because diverse new forms arise as a result of changes in ancestral forms. In theories of biological evolution, for example, one imagines an ancestral population of bears, some of which migrated farther and farther north and, as a result of selection, became larger and ultimately white, to make the different species we see today.

Similarly, the problem of explaining the diversity of cultures coincides with the problem of explaining change of cultures. In a theory of cultural evolution, one might imagine an ancestral culture carried by a group that split in two. From the ancestral customs, new customs might arise by modification, until the cultures of the two groups hardly resembled one another. After fewer than 200 years, the

Understanding Behaviorism: Behavior, Culture, and Evolution, Third Edition. William M. Baum. © 2017 John Wiley & Sons, Inc. Published 2017 by John Wiley & Sons, Inc.

British colonists who originally populated America differed from the British in speech, dress, and governance. The possibility of a parallel arises: Might we explain cultural evolution by the same kind of theory as biological evolution—as an outcome of selection acting on variation?

As mentioned in earlier chapters, the details of the account are relatively unimportant. Some may prove wrong, and the explanation of culture will change as new ideas arise. Our goals are only to demonstrate that a behavioral account is possible and to show that the account is sufficiently complex to be plausible.