In natural groups of mammals, there is a variety of social influences which seem to inhibit or facilitate the expression of instinctive behaviour-patterns, and indeed which contribute importantly to the form the repertoire of behaviour characteristic of the species takes. Such influences include what goes under the terms ‘social facilitation’ and ‘imitation’, as well as other terms such as ‘identification’ which imply a special affectional relationship.

From an analysis of the evidence about these influences on monkeys and apes, it is clear that negative experimental findings have often been due to the limitations of the experimental procedures, and that some of the positive findings are difficult to interpret or assess for validity because of deficient method. By and large, there is convincing observational evidence, chiefly from informal developmental and from field studies, that young monkeys and apes acquire certain basic feeding and avoidance habits chiefly by applying their exploratory tendencies to places and objects indicated in the behaviour of their mothers or others of the group.

Although, in terms of learning operations, it is unlikely that much more than stimulus-enhancement or place discriminations is usually involved, a ‘new’ motor sequence almost never being in evidence, there is no doubt that the affectional situation of the participants is crucial as to whether a ‘demonstrator’ is attended to, closely approached, and ‘imitated’, or not. The nature of the affectional variables and their influence upon learning require extensive experimental study and analysis, and a comparison with related forms of early learning, such as imprinting, can then be made.