Effects of Different Forms of Early Social Interaction on Shock-Induced Aggression in Mice

The experiment was conducted to determine the effects of rearing and brief aggressive encounters on shock-induced fighting. At weaning, 72 male mice were placed in isolate or communal cages. An equal number of subjects from each rearing condition were given brief encounters with either male or female conspecifics at 7-day intervals for 8 wk. At 85 days of age mice were paired within treatment conditions and tested for shock-induced aggressiveness. Isolate-reared mice fought significantly more often than did communally housed animals. Subjects given encounters were more aggressive than those not given the treatment.