AbstractsPsychology

Rhesus monkeys and chimpanzees that have been separated from their mothers, either at birth or some months later, and raised under restricted conditions in the laboratory, display stereotyped behavior patterns that are not usually seen in primates captured in the field (Davenport & Menzel, 1963; Mason & Green, 1962; Nissen, 1956) or in animals raised by their mothers in the laboratory (Jensen & Tolman, 1962). One of the most commonly observed forms of stereotypy in monkeys and chimpanzees is toe- or thumb-sucking (Masan, 1963); monkeys also display patterns of crouching, self-clasping, and rocking (Bernstein & Masan, 1962). Chimpanzees reared in isolation show more elaborate forms of stereotyped behavior, including rocking, swaying, twirling, head-banging, eye-poking, hand-clapping, and unusual limb-posturing. Davenport and Menzel (1963) provide a good description of stereotypy in such animals.