Socially facilitated reduction of the fear response in rats raised in groups or in isolation.

Abstract

Rats were tested in an approach-avoidance situation using food and shock. Experiment 1 involved 72 Ss[subjects] in a 2 x 2 factorial design comparing the effects of group or individual testing following group or individual shock at the goal. Experiment 2 involved 48 Ss in a 2 x 2 factorial design comparing effects of rearing Ss in groups or in isolation on 2 of the conditions from Experiment 1. Ss tested in groups approached significantly more than those tested individually, whereas group vs. individual shock made no difference. Ss raised in groups approached more and showed the "group effect" significantly more than Ss raised in isolation.