External and Internal Influences on Aggression in Captive Group-living Monkeys*

Infant nonhuman primates, particularly Old World monkeys and apes, typically interact with a number of different types of conspecifics on a daily basis. The interactants range from mothers and matrilineally related kin to unrelated adult females and males. In addition, a variety of different behavior patterns can occur. An infant can be the object of extremely solicitous and nurturing behavior, and, in a matter of seconds, the same infant can become the object of a murderous attack. Moreover, a wide range of behavioral actions is possible from most of the members of a group. In order to render the task of describing the various interactions between infants and other group members more manageable, this contribution will be restricted to interactions between infants and mothers, infants and adult males, and infants and nonmaternal females.