Social Factors Affecting Emotionality and Resistance to Disease in Animals: IV. Differential Housing, Emotionality, and Walker 256 Carcinosarcoma in the Rat

Abstract

Two experiments were conducted in which male, Sprague-Dawley rats were housed individually or in groups of 5 to 7 per cage from weaning until maturity. On the standard tests of emotionality there were large and consistent differences in emotional reactivity between the differentially reared groups. Also, systematic observation of reactions to handling showed significantly more startle, vocalization, and resistance to being picked up in the individually-housed animals. There were no differences between the group- and individually-reared animals in their responses to the transplanted tumor.