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 [email protected]


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.