Network formation during social integration in juvenile vervet monkeys

Abstract

Understanding the development of social relationships, or the process of socialization, can provide insights into the processes by which social network structures emerge and vary across species. In this analysis, we investigated the process of network formation from a developmental perspective using data from three groups of wild vervet monkeys, Chlorocebus pygerythrus . We used a dynamic social network approach that allowed us to capture patterns of social change over time. Specifically, we considered the temporal dynamics of two separate interaction networks, spatial and grooming associations, and investigated these patterns between the sexes. We used these data to test predictions derived from a developmental framework on relationship formation put forward by Kohn (2019, Animal Behaviour , 154 , 1–6). We found that females and males differed in their grooming patterns but were similar in their spatial associations. Furthermore, spatial proximity ego-networks showed seasonal patterns, whereas grooming ego-networks did not. When all relevant centrality measures were considered in concert, we found evidence to suggest that a distinctive network structure forms across the course of development, with ego-networks composed of few strong ties and many weak ties, regardless of behaviour and sex. However, these networks were not produced according to the processes described by Kohn (2019), perhaps because Kohn's framework is concerned mainly with network composition and not structure. Overall, our results provide evidence for social niche construction across development, with the formation of a core social ‘bubble’ of strong ties that can provide a consistent and predictable immediate social environment. More broadly, these patterns suggest that network formation is a process of ongoing adjustment to the social environment, and not an attempt to meet an optimal end goal. • We examined sociality in vervets following Kohn (2019, Animal Behaviour , 154 , 1–6). • Vervet monkeys did not develop following Kohn's three socialization phases. • Spatial ego-networks were seasonal; male and female grooming ego-networks differed. • Spatial and grooming ego-networks had few strong ties and many weak ties. • Social integration involves continual adjustments via social niche construction.