Fifteen?day?old rats were subjected to one of three housing conditions: mother?and?peer (family), peer, and isolation conditions. At 24 days of age, all subjects were rehoused individually. In Experiment 1, play behaviors were monitored in like?raised pairs. Despite their gross lack of social experience, isolation?reared subjects did not exhibit a deficit in frequencies of rough?and?tumble play. It is concluded that the fundamental motivation for rough?and?tumble play is relatively independent of prior learning in rats. Indeed, their elevated dorsal contacts suggested that isolation?raised subjects may have higher appetitive motivation for play. In Experiment 2, the levels of social motivation were compared between family? and isolation?raised animals, using a T?maze. The isolation?raised animals made reliably more choices for social interaction reward over food reward than family?raised animals. Although inconclusive, the results from the two experiments suggest that prolonged social isolation increases the appetitive motivation for social play. © John Wiley & Sons, Inc. Copyright © 1992 John Wiley & Sons, Inc.
