Some Evolutionary Aspects of the Food-Procuring Group Behavior in Phylogenesis of Primates

The peculiarities were studied of the intragroup competitive and cooperative behavior of primates differing by the level of phylogenetic development, beginning from low-organized species of the higher primates to high-organized anthropoid monkeys (Callithrix jacchus, Cebus apella, Macaca mulatta, Papio hamaofrijas, Pan troglodytes). It has been shown that in all monkeys, under conditions of competitive feeding situation, there were changes of the complex behavioral forms observed at individual learning. Under conditions of the activity in pairs, the females of platyrrhine (New World) and lower narrow-nose (Old World) monkeys lost the possibility to realize the skill and food needs, so the programmed tasks were solved predominantly by the males. In chimpanzees, the change of indices of instrumental activity involved to the equal degree the male and female, and solution of the alternation task was higher in individual experiments. The age differences were revealed in the competitive behavior of chimpanzees in group. The realization of formed skills depended on the complex of factors including the requirements dominating in the given situation and the age and typological peculiarities, as well as the social rank of each monkey in the community. In rhesus macaques the capability for cooperative interaction was revealed under conditions of complex operant activity.