Tuesday, December 23, 2008

Four Fallacies of Evolutionary Psychology

In their current issue on evolution, Scientific American takes a look at four of the fallacies perpetuated in evolutionary psychology. This is an excellent article that uphends some commonly held "widsom" of how the mind evolved. I'm not sure I agree with all of Buller's claims, but he makes some credible arguments.

Got to give him credit - he's taking on Steven Pinker here, which is no small task.

Evolution of the Mind: 4 Fallacies of Psychology

Some evolutionary psychologists have made widely popularized claims about how the human mind evolved, but other scholars argue that the grand claims lack solid evidence

By David J. Buller

Diorama of a Stone Age man as he might have lived some 15,000 years ago was photographed at the Hall of Human Origins at the American Museum of Natural History in New York CIty. Grant Delin.

Key Concepts

  • Among Charles Darwin’s lasting legacies is our knowledge that the human mind evolved by some adaptive process.
  • A major, widely discussed branch of evolutionary psychology—Pop EP—holds that the human brain has many specialized mechanisms that evolved to solve the adaptive problems of our hunter-gatherer ancestors.
  • The author and several other scholars suggest that some assumptions of Pop EP are flawed: that we can know the psychology of our Stone Age ancestors, that we can thereby figure out how distinctively human traits evolved, that our minds have not evolved much since the Stone Age, and that standard psychological questionnaires yield clear evidence of the adaptations.

Charles Darwin wasted no time applying his theory of evolution to human psychology, following On the Origin of Species (1859) with The Descent of Man (1871) and The Expression of the Emotions in Man and Animals (1872). Ever since, the issue hasn’t been whether evolutionary theory can illuminate the study of psychology but how it will do so. Still, a concerted effort to explain how evolution has affected human behavior began only in the 1970s with the emergence of sociobiology. The core idea of sociobiology was simple: behavior has evolved under natural and sexual selection (in response to competition for survival and reproduction, respectively), just as organic form has. Sociobiology thereby extended the study of adaptation to include human behavior.

In his 1985 critique of sociobiology, Vaulting Ambition, philosopher Philip Kitcher noted that, whereas some sociobiology backed modest claims with careful empirical research, the theoretical reach of the dominant program greatly exceeded its evidential grasp. Kitcher called this program “pop sociobiology” because it employed evolutionary principles “to advance grand claims about human nature and human social institutions” and was “deliberately designed to command popular attention.”

Times have changed. Although some self-identified sociobiologists are still around, the current fashion is evolutionary psychology. Evolutionary psychology maintains that adaptation is to be found among the psychological mechanisms that control behavior rather than among behaviors themselves. But, as the old saw goes, the more things change, the more they stay the same. Although some work in evolutionary psychology backs modest claims with careful empirical research, a dominant strain, pop evolutionary psychology, or Pop EP, offers grand and encompassing claims about human nature for popular consumption.

The most notable representatives of Pop EP are psychologists David M. Buss (a professor at the University of Texas at Austin and author of The Evolution of Desire and The Dangerous Passion) and Steven Pinker (a professor at Harvard University whose books include How the Mind Works and The Blank Slate). Their popular accounts are built on the pioneering theoretical work of what is sometimes referred to as the Santa Barbara school of evolutionary psychology, led by anthropologists Donald Symons and John Tooby and psychologist Leda Cosmides, all at the University of California, Santa Barbara.

According to Pop EP, “the human brain consists of a large collection of functionally specialized computational devices that evolved to solve the adaptive problems regularly encountered by our hunter-gatherer ancestors” (from the Web site of the Center for Evolutionary Psychology at U.C.S.B.). Just as evolution by natural and sexual selection has endowed all humans with morphological adaptations such as hearts and kidneys, Pop EP says, so it has endowed all humans with a set of psychological adaptations, or “mental organs.” These include psychological mechanisms, or “functionally specialized computational devices,” for language, face recognition, spatial perception, tool use, mate attraction and retention, parental care and a wide variety of social relations, among other things. Collectively, these psychological adaptations constitute a “universal human nature.” Individual and cultural differences are, by this account, the result of our common nature responding to variable local circumstances, much as a computer program’s outputs vary as a function of its inputs. The notable exceptions to this rule involve sex differences, which evolved because males and females sometimes faced distinct adaptive problems.

Moreover, because complex adaptation is a very slow process, human nature is designed for the hunter-gatherer lifestyle led by our ancestors in the Pleistocene (the period from 1.8 million to 10,000 years ago). As Cosmides and Tooby colorfully say, “our modern skulls house a Stone Age mind.” Pop EP proposes to discover our universal human nature by analyzing the adaptive problems our ancestors faced, hypothesizing the psychological mechanisms that evolved to solve them and then testing those hypotheses using standard-fare psychological evidence, such as paper-and-pencil questionnaires. Pop EP claims that a number of psychological adaptations have been discovered in this way, including evolved sex differences in mate preferences (males prefer nubility; females prefer nobility) and jealousy (men are more distressed by a mate’s sexual infidelity, women by emotional infidelity).

I believe that Pop EP is misguided. The ideas suffer not so much from one fundamental flaw as from many small mistakes. Nevertheless, recent critiques of evolutionary psychology point to some general problems of Pop EP.

Read the whole article.

For those who are not familiar with evolutionary psychology, here are a few articles mentioned in the print issue that can help flesh out the subject.

Evolutionary Psychology - From The Stanford Encyclopedia of Philosophy
Evolutionary Psychology: A Primer -Center for Evolutionary Psychology
Historical Evidence and Human Adaptations - A paper by Jonathan Michael Kaplan


Anonymous said...

Dear Dr. Buller,

Your well meaning critiques of Pop EP will not chip away at what is a massive accumulation of evidence. Would you agree that even "pop" EP is better rooted in testable theory than psychoanalysis, Freud, Marx, and Social Science? Not perfect, but probably more useful a paradigm than previous ones!

william harryman said...

Thanks for the comment, but you might want to leave it at their site, where he might see it.


Star Larvae said...

Slightly afield, but you might find interesting this politics of sociobiology