Kinship as constraint: Social aging in kin-structured groups

Irene Godoy

Centre for Research in Animal Behaviour (CRAB), University of Exeter

The dramatic increase in human life expectancy poses new challenges for health care systems. Among those challenges is that social isolation and loneliness as risk factors for mortality are highest among the elderly. We know that the social networks of adults tend to decrease in size with advancing age. However, what factors influence the rate at which an individual’s social network decreases? The answers to this question are critical to inform interventions aimed at improving late-life outcomes. In my talk, I will discuss comparative research in free-ranging, long-lived species to address age-related declines in human social integration. I will focus on non-human primates because of their close evolutionary link to humans and their long lifespans. Research in non-human primates has demonstrated similar age-related declines in sociality, though the drivers of these patterns are not well-understood. Group-living primates typically show strong kin biases in their association patterns. One key factor that may thus contribute to individual differences in social aging is kinship dynamics, as the type and number of close kin available changes across an individual’s lifespan. Drawing on data from a wild capuchin population, I will present results showing that both males and females show declines in their rates of spatial association as they age. Interestingly, age-related declines vary depending on the kinship relationship with social partners, and these effects are sex dependent. I will discuss how these (and other) results shed light on some of the myriad ways in which kinship dynamics may place constraints on how ‘social’ individuals can remain across development.