VOLUME 44, NUMBER 15 · OCTOBER 9, 1997 Exchange Evolutionary Psychology: An Exchange By Harold Kalant, Steven Pinker, Werner Kalow, Reply by Stephen Jay Gould In response to Darwinian Fundamentalism (JUNE 12, 1997) To the Editors: Evolutionary psychology is the attempt to understand our mental faculties in light of the evolutionary processes that shaped them. Stephen Jay Gould [ NYR, June 12 and June 26] calls its ideas and their proponents "foolish," "fatuous," "pathetic," "egregiously simplistic," and some twenty-five synonyms for "fanatical." Such language is not just discourteous; it is misguided, for the ideas of evolutionary psychology are not as stupid as Gould makes them out to be. Indeed, they are nothing like what Gould makes them out to be. Evolutionary psychology often investigates the adaptive functions of cognitive and emotional systems—how natural selection "engineered" them to solve the kinds of problems faced by our ancestors in their struggle to survive and reproduce. The rationale follows from two premises Gould himself states nicely: (1) "I…do not deny either the existence and central importance of adaptation, or the production of adaptation by natural selection. Yes, eyes are for seeing and feet are for moving. And, yes again, I know of no scientific mechanism other than natural selection with the proven power to build structures for such eminently workable design." (2) "The human brain is the most complicated device for reasoning and calculating…ever evolved on earth." Quite so. First, adaptive design must be a product of natural selection. Complex organs like eyes have many precise parts in exacting arrangements, and the odds are astronomically stacked against their having arisen fortuitously from random genetic drift or as a byproduct of something else. Second, the brain, like the eyes and the feet, shows signs of good design. The adaptive problems it solves, such as perceiving depth and color, grasping, walking, reasoning, communicating, avoiding hazards, recognizing people and their mental states, and juggling competing demands in real time are among the most challenging engineering tasks ever stated, far beyond the capacity of foreseeable computers and robots. Put the premises together—complex design comes from natural selection, and the brain shows signs of complex design— and we conclude that much of the brain should be explained by natural selection.