Don’t throw the evolutionary psychology baby out with the bathwater

Evolutionary psychology is under attack again.  Leading the charge is Sharon Begley who has an incendiary piece in Newsweek entitled, “Why Do We Rape, Kill and Sleep Around?”.  Sharon is a very insightful science writer, but her arguments seem to be driven as much by outrage as by data.

It has always been a weakness of the field of evolutionary psychology that the bulk of the research has consisted of hypotheses (some would say just-so stories) rather than data.  More controversially, some of the conclusions which followed have been politically uncomfortable to consider. But the real question is not whether they are uncomfortable but whether they reveal something meaningful about the human condition.  The proper way to arrive at that conclusion is to sharpen our thinking and carry out experiments to test these hypotheses.  Indeed, in recent years the field has moved to more rigorous forms of inquiry and data is beginning to emerge which serves to test some of the hypotheses that have been put forward.  As with any field of science, some of the hypotheses that have been put forward have been found wanting.  There is nothing really new about that.  What makes Sharon’s piece newsworthy (but at the same time a bit slanted) is that at least some of the hypotheses that have fallen were those very ones that were viewed as uncomfortable.

But frankly, these are arguments over details, the sort of thing that scientists hash out in the Q&A sessions that are the staple of scientific meetings. The bigger criticism for evolutionary psychology (evident in Sharon’s piece but much more so in the commentary by David Brooks in the New York Times) is that our brains do not consist of pre-programmed modules that were set in stone during the Pleistocene. Rather, it seems that the adaptation which has allowed us to flourish as a species is the fluidity with which we use our neural apparatus to the task at hand, whatever it may be.  This plasticity is why my brain, whose genetic programming most certainly derives from my evolutionary history, is able to master such a modern task as typing. By presenting the brain as a series of modules with fixed functions, evolutionary psychology painted itself into a corner.  The challenge for the field is really to understand something much more nuanced: how plasticity interacts with innate neural networks to produce modern behavior.

[For those interested in further commentary, some of it quite detailed with respect to the individual arguments put forward by Begley, I recommend you go hereand here and here.]