Evolutionary psychology, like sociobiology or Marxism, has become associated with controversy. Why should it, and why has it? Yes, debates about evolution totter endlessly along, and psychology remains a discipline that sometimes seems orphaned by both humanities and the hard sciences. Why should combining psychology and evolution ignite a confabulation of loathing, fear, and scientific vitriol?Four reasons, by my reckoning.First, not only do we (here, a royal 'we' of evolutionary biologists like myself) expect very many people to not understand evolution, because it is too simple and mechanistic for our meaning-laden world; we also predict that people should reject evolution because one of its core provisos is that people, you and me, should generally behave so as to maximize their relative fitness. Competition, survival, reproduction, of the fittest? Not me, you? For shame. Evolutionary theory indeed predicts that we should each believe, or at least rationalize, ourselves to be mutualistic, altruistic, and moral nearly to a fault, because that is one of the best ways to get the edge on, or into, our competitors, be they individuals or other groups1. So are you a believer now? Evolution is controversial because its very existence seems to attack our core beliefs about our own goodness, and the biggest questions regarding human purpose.Second, psychology purports to study the brain, but can it do so scientifically, like other disciplines? Will generating questionnaires, and treating humans in modern, novel environments like lab rats, illuminate the inner-workings of the most complicated known structure in our universe? The hard sciences are hard because they are reductionistic - they infer mechanisms, processes, parts that, combined together, explain the workings of whole systems. They conduct controlled, predictive experiments. They have conceptual frameworks built from math and data, not fashion. So armed, they ratchet forward, fact by incontrovertible fact. 'Soft' disciplines are soft because they reject reduction, and indeed often claim post-modern relativity for all. Psychology is a soft science because it cannot reduce - there is no place to go except neuroscience, which would swallow it up with nary a belch, given the chance. Evolutionary biology is historical but also reductionist, in that it specifies the precise set of processes whereby all phenotypes have come to be, and change, and it tells us how to discover what functions they serve. As such, it illuminates all domains of science, from genetic sequence through to human behavior - or at least would, if allowed to by academic practitioners. Psychology is controversial because it is a soft science trying to answer the hardest of question, how the brain works. It can't.Third, evolutionary psychology was forged in a crucible of polemic, as specific schools of thought, such as the school of highly-modular fitness-increasing brain functions developed by Leda Cosmides and John Tooby. These researchers staked out strong claims, trained talented students, and attacked intellectually-neighboring tribes. Adopting one side of polarized viewpoints, and sticking to it, remains a highly-effective route to scientific notoriety, even though in almost all such fierce academic battles both sides are partially correct, and both partially wrong. We are a deeply tribal species, and we love observing, or joining in, a good scrap. In this case, though, an entire emerging, integrative field has become conflated with extreme views of how the mind thinks, which has made for inviting targets but distracted from the much more general usefulness of evolutionary thinking. Will psychology eventually be torn asunder, like anthropology has been into post-modern, anti-evolutionary 'culturalists' versus mainstream but human-centric and evolution-minded biologists? Will economics? One can only hope.Fourth, 'psyche' indeed means 'soul', and for psychologists, the hostile tribes of evolutionary biology threaten to steal it away, and subsume their discipline in its mechanistic, reductionist embrace. The irony here is that if there is any discipline that has no soul - that is, no unifying conceptual framework - it is psychology, which has flitted from one arbitrary, more or less imaginary construct to the next since Wilhelm Wundt began treating introspection as data. Of course psychology has produced deeply fascinating insights over its many years. Of course we need a top-down approach to understanding how the brain works, to meet neuroscience inexorably burrowing up from the bottom. But don't we need a mind-set that recognizes that the brain and mind have evolved, like finches and opposable thumbs? Any discipline would fight like hell to defend its very existence, or at least resist radical transformation at the hands of competitors. Controversy indeed often leads to scientific revolution, with casualties on both sides.Evolutionary psychology is like evolutionary anything: it is founded on a way of thinking about how the world works, how it has come to be, and how to understand it. It works by telling us what hypotheses to test, what data to collect, and how to interpret our results. The fires of controversy over this emerging field have generated both heat and light, but better understanding of their sources will, I think, help us to control the flames and put them to better use.Reference

  1. Alexander, Richard D. 1987. The Biology of Moral Systems. Aldine De Gruyter, New York.