Biosocial determinants of health outcomes: new approaches and evidence

Health disparities among older adults are multifactorial. Risk factors are embedded from a matrix of biological, social, psychological, and contextual exposures, accumulated across the life trajectory. Sociologists have to date almost exclusively focused on the social aspects of health and overlooked biological and genetic potential, leading to estimation bias of social factors. Moreover, the majority of research examining the link between health and socioeconomic status (SES) seldom presents a causal inference. A knowledge gap also exists between the West and China. While there is a well-established relationship between SES and health among older people in Western societies, the SES-health gradient has not yet been established in different social and historical context. The three independent essays in this thesis adopts a biosocial approach integrating life course perspective and fundamental causes theory, in order to bridge the disjointed knowledge on contextual, social and biological influences on health, measured by objective indicators of biomarkers and cognitive ability. I use data from the China Health and Retirement Longitudinal Survey (CHARLS) and the Health and Retirement Study (HRS) from the US to tackle the following three research questions:1) How do macro level contextual factors and individual socioeconomic status influence health in China? 2) Is the well-established relationship between socioeconomic status and health causal? 3) How do genetic factors moderate demographic and socio-economic effects on the decline of cognitive functions? The key findings are: first, the individual level SES-health link is consistent across China and the U.S among the older population. Provincial variations in economic development, income inequality, and health infrastructure are associated with a range of health outcomes for Chinese midlife and older adults. Second, genetic risk score helps to identify a causal educational effect on health. Third, the genetic effect of education changes with age and across cognitive domains among the HRS sample.