Some determinants of play and exploration in chimpanzees.

Abstract

Six young chimpanzees (3 to 8 yr.) were exposed successively to 15 different stimulus situations during a total of 112 6-min. sessions. The introduction of novel or different stimulus objects increased general responsiveness. With repeated exposure to these objects, a decrease in total responsiveness occurred within sessions for all animals and from session to session for all but the more highly responsive animals. For a given set of objects there was an increase in responsiveness from the last minute of one session to the first minute of the subsequent session. Certain object preferences were exhibited by all animals. The three younger animals were more responsive than the three older animals. All animals were more variable (in terms of frequency of contacts, shifts, and withdrawals) when they were more highly responsive (in terms of total time of contact). Motivation to play and to explore was maintained as long as new objects were periodically introduced. Specific characteristics of the stimulus situations were thus shown to be determinants of play and of exploration, and the behavior was shown to be patterned in time in certain specific ways.