Field studies of natural mammal populations present powerful opportunities to investigate the determinants of health and aging using fine-grained observations of known individuals across the life course. Here, we synthesize five decades of findings from one such study: the wild baboons of the Amboseli ecosystem in Kenya. First, we discuss the profound associations between early life adversity, adult social conditions, and key aging outcomes in this population, especially survival. Second, we review potential mediators of the relationship between early life adversity and survival in our population. Notably, our tests of two leading candidate mediators-social isolation and glucocorticoid levels-fail to identify a single, strong mediator of early life effects on adult survival. Instead, early adversity, social isolation, and glucocorticoids are independently linked to adult lifespans, suggesting considerable scope for mitigating the negative consequences of early life adversity. Third, we review our work on the evolutionary rationale for early life effects on mortality, which currently argues against clear predictive adaptive responses. Finally, we end by highlighting major themes emerging from the study of sociality, development, and aging in the Amboseli baboons, as well as important open questions for future work.

Previous research has documented a consistent association between current socioeconomic status (SES) and cytomegalovirus (CMV). Early life is likely a critical period for CMV exposure and immune development, but less is known about early-life socioeconomic factors and CMV, particularly in older age populations. Using data from the Health and Retirement Study, we investigated the association between life course socioeconomic disadvantage and immune response to CMV among older adults.
Using ordered logit models, we estimated associations between several measures of socioeconomic disadvantage and the odds of being in a higher CMV Immunoglobulin G (IgG) response category in a sample of 8,168 respondents aged older than 50 years.
We found a significant association between educational attainment and CMV IgG response. Those with less than a high school education had 2.00 (95% confidence interval [CI]: 1.67-2.40) times the odds of being in a higher CMV category compared to those with a college degree or greater. In addition, we also observed a significant association with parental education and CMV response. Individuals with parents having 8 years or less of schooling had 2.32 (95% CI: 2.00-2.70) times the odds of higher CMV response compared to those whose parents had greater than high school education.
CMV IgG levels in older adults are associated with both early-life and adult SES. Life course socioeconomic disadvantage may contribute to disparities in immunological aging.

A large body of research identifies the critical role of early-life social contexts such as neighborhoods and households in shaping life course trajectories of health. Less is known about whether and how school characteristics affect individual health and contribute to population health inequality. However, recent scholarship argues that some school environments are so stressful due to high levels of violence, disorder, and poverty that they may be \"toxic\" to student health, but this hypothesis has not been tested using population data. Integrating insights from the life course perspective and stress process model, we use rich longitudinal data from the National Longitudinal Study of Adolescent to Adult Health (n = 11,382), diverse markers of physiological functioning and psychological well-being, and multilevel regression models to examine whether and how school characteristics shape trajectories of physiological dysregulation and depressive risk from adolescence through early adulthood. Findings reveal that, across multiple measures of physiological functioning and psychological well-being, the social and structural characteristics of schools play an essential role in shaping health risk from adolescence through young adulthood-long after students left school. In particular, indicators of school-level violence and perceptions of safety and school social disconnectedness had especially strong associations with health risk in both the short- and long-term. School socioeconomic composition was also strongly associated with physiological dysregulation in young adulthood, net of individual and neighborhood socioeconomic exposures. Together, findings from this study suggest that school environments can serve as early-life stressors in the lives of young people that unequally shape health trajectories and contribute to broader patterns of health inequality.

BACKGROUND: The incidence of major depression among adults has been shown to be socially differentiated, and there are reasons to seek explanations for this before adulthood. In this cohort study, we examined whether academic performance in adolescence predicts depression in adulthood, and the extent to which externalizing disorders explain this association.
METHODS: We followed 26,766 Swedish women and men born 1967-1982 from the last year of compulsory school, at age about 16, up to 48 years of age. We investigated the association between grade point average (GPA, standardized by gender) and first diagnosis of depression in national registers of in- or out-patient psychiatric care. We used Cox proportional hazards models, adjusting for lifetime externalizing diagnoses and potential confounders including childhood socioeconomic position and IQ.
RESULTS: During follow-up, 7.0% of the women and 4.4% of the men were diagnosed with depression. A GPA in the lowest quartile, compared with the highest, was associated with an increased risk in both women (hazard ratio 95% confidence interval 1.7, 1.3-2.1) and men (2.9, 2.2-3.9) in models controlling for potential confounders. Additional control for externalizing disorders attenuated the associations, particularly in women.
CONCLUSIONS: The findings suggest that poor academic performance is associated with depression in young adulthood and that the association is partly explained by externalizing disorders. Our results indicate the importance of early detection and management of externalizing disorders among children and adolescents.