Behavioral and Brain Sciences

Short Communication

Identifying adaptation by dysfunction

Donald F. Klein a1
a1 Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY 10032


Specifying exact selection pressures for identifying adaptations is unnecessary. Novel behaviors are not spandrels since they can only develop because of prior functions. An adaptationist approach has a high prior probability, whereas spandrel hypotheses attempt to prove a negative. The concept of maladaptive spandrel is criticized. The utility of dysfunctional states for identification of adaptations gone wrong is emphasized.