Sociocultural Patterning of Biological Processes: An Examination with Biological Health and Brain Functioning

This dissertation investigates the relationship between the biological system and the sociocultural environment. For a long time, the “nature” (biological processes that are considered as part of the genetic inheritance) and “nurture” (external environment) are thought of as two separate sources of influence on behaviors. However, recent work demonstrate that the biological system is inherently embedded in and shaped by the sociocultural environment. My dissertation builds on this emerging line of work and extends the current literature by examining three questions. In Chapter 1, I provide the theoretical background of my research questions. In Chapter 2, I present a study examining how human culture may shape the structural properties of the brain. I showed that there exists systematic cultural difference in the GM volume of several brain regions. Importantly, this cultural difference is more pronounced among individuals carrying the “plasticity allele” which predisposes them to be more sensitive to the cultural context. In Chapter 3, I focus on the aspect of the sociocultural environment that is characterized by inequality, and I investigate its consequences on biological health. In the first study, I showed that racial residential segregation and income inequality jointly exacerbated the COVID-19 fatalities in large U.S. cities during the pandemic. In the second study, I showed that while the experience of discrimination can be stressful, recognizing negative events as discrimination and reporting the discrimination could reflect a resilient psyche, which in turn predicts better long-term health. In Chapter 4, I demonstrate how biological health and brain functioning are inherently related to each other. I found that poor biological health is associated with a less optimal functional organization of the whole-brain network, over and above of the effect of aging and other factors that can compromise brain functioning. Finally, in Chapter 5, I summarize the findings and identify future directions for this research.PhDPsychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/174630/1/qinggang_1.pd