The effects of social isolation on the behavior of juvenile domestic cats.

The effects of social isolation on the behavior of juvenile domestic cats were assessed by rearing 4 male and 4 female infant kittens in each of the following rearing conditions: (1) mother-littermate; (2) mother-only; (3) brooder-littermate; and (4) brooder-only. They were then tested twice a week individually and twice a week socially from 2 to 6 1/2 months of age in a playroom, utilizing multiple categories of behavior. The mother-only-reared juveniles were hyperactive in both object play (when tested individually) and social play. The brooder-only-reared kittens displayed enhanced socially directed behavior and were generally hypergregarious, whereas the brooder-littermate-reared kittens displayed retarded social behavior. Observations indicated that littermate-deprived kittens did not learn social communication skills and that some prolonged separation effects existed for littermate-reared kittens. The results suggest that the determinants of social play are more complex than the determinants of object play.