“…Captive chimpanzees probably engage in more aggression than their freeranging counterparts [van Hooff, 1974;Wilson and Wilson, 1968], and a large number of contexts have been identified which may elicit agonistic encounters. These include introductions of unfamiliar animals [Alford et al 1995;Wilson and Wilson, 1968], reunions between familiar animals [Alford et al, 1995;Bygott, 1979;Goodall, 1986;de Waal and Hoekstra, 1980], interventions on behalf of youngsters in conflicts [Goodall, 1986;de Waal and Hoekstra, 1980], redirected aggression resulting from "frustrating" situations [Goodall, 1986;de Waal and Hoekstra, 1980], arousal during feeding [Bloomsmith et al, 1994;Bygott, 1979;Goodall, 1986;Wrangham, 1974], and competition for access to sexually receptive females [Hasegawa et al, 1990;Rumbaugh et al, 1989;de Waal and Hoekstra, 1980].…”