Project Summary Although accumulating evidence in humans points to improvements in emotional life with age, even in the context of physical and cognitive health challenges, the mechanisms that support those improvements are largely unknown. One possibility is that aspects of the social environment and social relationships guard against deleterious aging effects and thus promote wellbeing. Understanding the interplay between social environment and cognitive, affective, and neurobehavioral health outcomes across the lifespan is critical for developing effective interventions for people who suffer from the deleterious effects of aging, including depression and loneliness. Nevertheless, it is not ethical to manipulate humans’ social relationships in order to test causal hypotheses. To address this mechanistic question, we capitalize on a robust animal model of human social, cognitive, affective, and neurobehavioral aging – the rhesus monkey – in order evaluate whether robust social environments and high-quality relationships promote and protect healthy affective, cognitive, and neurobehavioral aging while restrictions of the social environment compromise it. Additionally, we evaluate whether social interventions, namely increasing access to high quality social partners, may improve cognitive, affective, and neurobehavioral outcomes once they have been compromised by aging processes. We will restrict and then rejuvenate the social environment in both young and aged monkeys, and measure neurobehavioral function (cognition, affect, and neuroimaging measures of brain structure and function) concurrently with these manipulations. In this way, this program of work represents a critical first step in determining the mechanistic impact of social environment on neurobehavioral aging in addition to evaluating a potential intervention that could benefit individuals who have experienced unhealthy aging.

Project Narrative Despite the deleterious effects of aging on physical and cognitive health, many people’s emotional lives become more positive with age. A subset of people, however, experience negative emotional outcomes including depression and loneliness that have significant consequences for physical health and increase risk of morbidity and early mortality. The goal of this project is to investigate one possible mechanism that might subseve these effects – the possibility that robust social environments and the quality of social relationships promotes healthy aging – in a robust animal for human social, cognitive, affective, and neurobehavioral aging.