Environmental factors influencing the affiliative behavior of male and female rats (Rattus norvegicus)

Three experiments were conducted to investigate the influence of rearing and housing manipulations on the affiliative behavior of male and female rats. Animals were tested in same-sex pairs in an open field for time spent in contact and for socially facilitated activity. The results revealed a sex difference in both the degree and the form of affiliative behavior of rats. In general, males were more affiliative and more responsive to a second animal. Males engaged in more rough-and-tumble play, whereas females spent more time in social grooming. Housing conditions of adult animals and rearing conditions were found to influence the degree to which males engaged in male-like affiliative behaviors and females engaged in female-like affiliative behaviors. Social behavior appears to be a function of the interaction between the affiliative repertoire of the animals involved, the nature of the social stimulus, and the features of the environment.