Abstract
Using electrophoretic and serological genetic markers each of 17 potentially inbred matings in three groups of rhesus monkeys could be classified as either inbred or noninbred matings. Although nine of these 17 matings involved either father‐daughter or paternal half‐sib matings, only 7.4 were expected by chance alone. At least two, and possibly as many as three, of the nine cases of inbreeding involved father‐daughter matings. Thus, no evidence of avoidance of inbreeding was observed in the closed captive groups of rhesus monkeys studied. Colony management policies must be developed to minimize the opportunity for or the deleterious effects of both father‐daughter and half‐sib matings. Furthermore, kin selection theory should consider why kin recognition, if it occurs, does not lead to avoidance of inbreeding.