Monkey's Social Roles Predict Their Affective Reactivity

Abstract

Accumulating evidence demonstrates that the number of social connections an individual has predicts health and wellbeing outcomes in people and nonhuman animals. In this report, we investigate the relationship between features of an individuals' role within his social network and affective reactivity to ostensibly threatening stimuli, using a highly translatable animal model - rhesus monkeys. Features of the social network were quantified via observations of one large (0.5 acre) cage that included 83 adult monkeys. The affective reactivity profiles of twenty adult male monkeys were subsequently evaluated in two classic laboratory-based tasks of negative affective reactivity (human intruder and object responsiveness). Rhesus monkeys who had greater social status, characterized by age, higher rank, more close social partners, and who themselves have more close social partners, and who played a more central social role in their affiliative network were less reactive on both tasks. While links between social roles and social status and psychological processes have been demonstrated, these data provide new insights about the link between social status and affective processes in a tractable animal model of human health and disease.

Keywords: Social networksSocial network analysisRankNonhuman primatesMacaca mulattaAffective reactivity.

Fig. 1

Affective reactivity during HIT. X represents means; error bars are 95% confidence intervals. Trial types are represented on the x-axis, with two body positions (Profile and Stare) and two distances (Far and Near)

Fig. 2

The relationship between social status and affective reactivity on the HIT (a) and ORT (b). Individual animals’ regression scores from component 1 of the principal component analysis are plotted on the x-axis