The role of social experience in the development of sexual competence in Rattus norvegicus

To clarify the hitherto ambiguous role of pubertal social experience in determining adult sexual competence in male Rattus norvegicus , the quality of the subjects' social interactions was manipulated. In Experiment 1, subjects were raised from weaning onwards in male-only groups, in groups with limited periods of social deprivation at various ages, or in total isolation. Only the latter showed a significant degree of sexual impairment. In Experiment 2, subjects were raised in mixed-sex groups, in total physical (but not visual or olfactory) isolation from a surrounding mixed-sex group, or in physical isolation except for one hour's social contact per day with a peer. All of these subjects were sexually competent as adults. It thus appears that, in the laboratory rat, social deprivation must consist of total physical and visual and/or olfactory isolation in order to produce a significant degree of sexual impairment.