One of the most thought-provoking books I read last Christmas was Robert Wright’s The Moral Animal, a popular account of evolutionary psychology. I really enjoyed it: it seemed to provide a lot of plausible mechanisms for the origins of many behavioral patterns we display, in a nice, Darwinian framework. The author wasn’t a strict nature over nurture type either, just wanted us to acknowledge that our everyday lives are affected by Stone Age biological impulses more than most of us would probably like to admit. And so I became something of an evolutionary psych fan, and went on to read The Rise and Fall of the Third Chimpanzee and other related popular books. Evolutionary psychology is a growing field and has many high-profile proponents, such as Steven Pinker.
Recently, however, the philosopher David Buller has started to question the foundations of evolutionary psychology (EP for short). This Slate article has a nice summary of Buller’s ideas, and his book Adaptive Minds is now on my buy list.
One of the fundamental tenents of EP is that there hasn’t been enough time for our minds to undergo evolutionary change since the Stone Age ended roughly 10,000 years ago. But recently it has been realised that evolutionary change can actually occur fairly rapidly under pressure: moreover, in the case of the human brain there is no need to really evolve new structures, just adapt the way the existing ones are used. In addition, to apply EP fully, we would have to know a lot more about the environment the Stone Age man lived in than we currently do.
As Buller points out, “We don’t even know the number of species in the genus Homo”—our direct ancestors—“let alone details about the lifestyles led by those species.” This makes it hard to generate good hypotheses. Some EP-ers have suggested looking to modern-day hunter-gatherers as proxies, studying them for clues about our ancestors. But this doesn’t get them far. For instance, in some contemporary African groups, men gather the bulk of the food; in other groups, women do. Which groups are representative of our ancestors? Surely there’s a whole lot of guesswork involved when evolutionary psychologists hypothesize about the human brain’s supposedly formative years.
I’m not sure if it’s just a very, very clever verbal gambit or if there’s really something to it, but Buller manages to draw some amusing parallels between intelligent design and EP.
There’s a nice irony here, since for years EP-ers have ridiculed opponents for not appreciating evolutionary theory’s core tenets. Buller goes so far as to note an eerie resemblance between EP and intelligent design, which also treats human nature as fixed and complete. The more persuasive claim is that there is no single human nature, and that we’re works in progress.
The jury is still out on this issue, like on so many other aspects of the origin and inner workings of our minds, but I’m convinced that this kind of stuff — along with the more hands-on cognitive neuroscience is among the most important and potentially most volatile scientific research being done today. Stone Age brains or not, we have to learn to understand ourselves better, and the very fact that this kind of dialogue is taking place indicates that we’re well on our way.