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.