Social deprivation and play in rats

Social interaction (play fighting) was studied in socially housed and individually housed juvenile rats (18–30 days of age). 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...