How Social Experiences Shape Health Across the Life Course
Understanding how our lived experiences influence long-term health is at the center of groundbreaking research led by Man-Kit (Karlo) Lei, an Affiliate of the Owens Institute for Behavioral Research (OIBR), Associate Professor of Sociology, and Co-Director of the Center on Biological Embedding of Social Events and Relationships.
Lei’s current project, Understanding Stress, Resilience, and Health across Life Course, is supported by $4.5 million in funding from agencies including the National Institute on Aging and the Centers for Disease Control and Prevention, as well as by the Mental Research Institute Foundation, reflecting the national significance of this work.
A Longstanding Collaboration Driving Innovation
This research builds on more than 15 years of collaboration between Lei and Steven Beach, Regents’ Professor of Psychology and Director of the Center for Family Research. What began as a shared interest has evolved into a highly interdisciplinary effort, bringing together scholars across the University of Georgia campus and beyond to tackle complex questions at the intersection of social and biological science.
When Inequality Gets “Under the Skin”
At the heart of Lei’s research is a powerful concept: social experiences—particularly stress, inequality, and adversity—can become biologically embedded over time.
His research project examines how these factors influence health, aging, and neurodegenerative risk, with a particular focus on Black communities. By combining social data with biological indicators, Lei and his team are revealing how disadvantages build over time and become embedded in the body across the life course.
Importantly, the research also highlights the role of resilience. Supportive relationships, strong social networks, and targeted interventions can interrupt harmful pathways and promote better long-term health outcomes.
New Insights into Early Neurodegenerative Risk
Recent studies led by Lei provide some of the clearest evidence to date linking social adversity to early biological indicators of neurodegeneration.
In work published in The Journals of Gerontology, Series A, his team found that cumulative socioeconomic disadvantage is associated with increases in a blood-based marker of nerve cell damage over time. Notably, these effects were not immediately visible but emerged gradually, underscoring how disadvantage accumulates and affects health across years.
A complementary study in The Journals of Gerontology, Series B, focused on Black women and revealed that experiences of racial discrimination accelerated age-related increases in the same biomarker, with effects becoming especially pronounced later in midlife. These findings align with the “weathering” perspective, which suggests that repeated exposure to adversity leads to cumulative biological wear and tear.
Together, this body of work demonstrates that inequality is not only social or psychological—it can also shape biological pathways linked to cognitive decline long before clinical symptoms appear.
Challenges—and Opportunities—in Interdisciplinary Research
Studying the intersection of social and biological processes presents unique challenges. Collecting both survey data and biological samples can increase participant burden, leading to higher attrition rates. Additionally, distinguishing the effects of social factors from natural biological variation requires sophisticated methodological approaches.
Despite these hurdles, Lei finds the work deeply rewarding. By shifting the focus from treating disease to preventing it, his research offers a more proactive approach to public health. It also provides critical insights into how building a more equitable society—and strengthening social support can improve population health and promote healthier aging.
Looking Ahead
Over the next five years, Lei aims to expand this research by increasing focus on neurodegenerative disorders and adopting a more comprehensive, multilevel approach. This includes examining how adversity operates at both individual and community levels and extending the research to additional populations to better understand both shared and unique pathways linking social experiences to health outcomes.
A Broader Perspective on Health
Lei’s work reinforces a critical takeaway: health cannot be understood through biology alone.
“Our bodies are biological entities,” he emphasizes, “but they are also carriers of social experience.”
By bridging social and biological sciences, this research advances a more complete understanding of the human condition—one that recognizes the profound impact of our environments, relationships, and lived experiences on long-term health.
Written by: Andrea Horsman
April 6, 2026