Social interaction (play fighting) was studied in socially housed and individually housed juvenile rat+D606). Pinning (an animal on its back, with the other on top) proved to be a simple measure of play which correlated highly with other measures of playful behavior (solicitive behaviors, following, rough-and-tumble play, and together-time measures). Play behaviors were markedly increased by social deprivation and reduced by social satiation. The results suggest that social play is a regulated process which can be easily quantified by the simple and objective measure of pinning behavior. © 1980, Academic Press, Inc.. All rights reserved.
