Effects of Group Size, Composition, Introduction Technique and Cage Apparatus on Aggression during Group Formation in Rhesus Monkeys

Abstract

Aggression directed toward rhesus monkey females was monitored for 2 wk. following group formation under several experimental conditions which included: (a) variation in the number of females (6, 12, 18) and the number of males (1, 2); (b) modifications in the cage apparatus (stripped, boxes and pipes, and visual barriers); and (c) differences in introduction technique (unfamiliar animals vs combination of two pre-existing groups). None of these treatments produced significant differences in the amount of aggression received per female. It was concluded that the extreme conditions inherent in the formation of a new group overshadowed the effects of physical and social variables which might have influenced aggression under more stable circumstances.