Behavioral and Brain Sciences

Short Communication

Cliff-edged fitness functions and the persistence of schizophrenia

Randolph M. Nesse a1
a1 Departments of Psychiatry and Psychology, The University of Michigan, Ann Arbor, MI 48104


Strong recent selection for social cognition may well explain the persistence of genes that predispose to schizophrenia. The specific mechanism responsible may be a skewed fitness function in which selection pushes the mean for advantageous mental traits perilously close to a “fitness cliff” where the system fails catastrophically in some individuals.