Personality, dominance experience, and the development of social behaviour in laboratory stumptail macaques (Macaca arctoides)

Abstract

The utility of the concepts of personality and social dominance for the explanation of the development of social behaviour in laboratory stumptail macaques was examined. A peer-rearing paradigm was used. Infants were separated from their mothers at eight days of age, reared in social isolation until three months of age, then given experimentally-controlled dominance experience with peers until fifteen months of age. It was found that socially-isolated infant stumptails were capable of exhibiting all of the communication signals examined in this study; they exhibited them in appropriate affective contexts; and they appeared capable of recognizing specific stumptail communication signals. In addition, they seemed capable of combining the units of communication into meaningful higher-order behaviour patterns, e.g., to enlist help in multi-animal agonistic interactions. It was found that individual stumptail macaques could be reliably ordered on each of Eysenck's three dimensions of personality, i.e., neuroticism, extraversion, and psychoticism; and that knowledge about these personality characteristics may enable the prediction of certain of the individual's behavioural characteristics. Furthermore, it was found that the personality characteristics of the individual at four months of age may be useful in predicting its personality characteristics at fifteen months of age, and also its future dominance status. It was found that if experimentally-manipulated dominance experience thwarted the attainment of this "predicted" dominance status, this led to specific changes in the personality characteristics of the individual in novel situations; if experimentally- manipulated dominance experience supported the attainment of "predicted" status, then the personality characteristics of individuals in novel situations did not change. Finally, dominance experience was found to affect the frequency with which dominance strategy behaviour was exhibited in newly-formed triads; but it was not found to affect the probability of dominance, submission, play, sex, or affiliation, in novel situations. It was concluded that the data supported a transactional model of causation.