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Man Kit Lei

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Assistant Professor

Man Kit (Karlo) Lei is an assistant professor in the Department of Sociology and is affiliated with the Center for Family Research (CFR) and the Center on Biological Embedding of Social Events and relationships (CBESER) at UGA. Dr. Lei’s research interest is in the sociology of health and well-being. Broadly, his research combines theories and methods across disciplinary boundaries to examine the social determinants of health and aging across the life span, with a particular focus on minority populations and disadvantaged communities. Recently, his efforts have been primarily guided by three questions:

1. How does a better understanding of the social determinant impact health and aging?

2. How and why do early adversity experiences impact well-being across the life course?

3. Why do only some, and not all people, exposed to social adversity develop poor health?

(A) Social determinants of health and aging across the life course

Recently, he integrated theory and methods to better understand the social determinants of health. He proposed a comprehensive model using contextual and race-related stress to identify the biophysiological pathways through which exposure to stress among minority youth and adults creates vulnerabilities affecting health/aging. His study extended prior research concerning the effect of contextual and race-related stress on health/aging in several ways. First, in terms of method, he proposed marginal structural modeling with continuous predictors to control potential selection effects. Further, associations reported in previous studies between stress and health/aging may have been inflated by shared methods variance. His research addressed this limitation by using both blood-derived biomarkers (e.g., inflammation cytokines and cardiovascular disease risk, and DNA-methylation based measures) and self-reporting to assess physical health. Second, the biopsychosocial mechanisms whereby stress factors influence health/aging have been given little consideration. He found that successful smoking cessation makes people appear biologically younger. Further, his recent study reported that psychosocial resources, inflammation, and weathering are pathways whereby contextual stresses affect long-term health and well-being. Finally, he also revealed that neighborhood collective efficacy protects against adverse effects of social stress on health/aging. These findings expand sociological literature as well as contribute to the growing field of biosocial studies of health and illness.

(B) Early adversity and health outcomes in adulthood

His second research line has focused on how early adversity influences health/aging by becoming biologically embedded. He has identified the mechanisms by which early adversity affects health outcomes as crucial to advancing health research. His study provided evidence that childhood adversity "gets under the skin" to accelerate the onset of pubertal development, which in turn increases cardiovascular disease risk many years later. Further, in terms of method, many studies have relied on either retrospective or prospective adversity measures. Thus, the effect of different assessment methods on potential stress-buffering processes remains largely unknown. He indicated that although the retrospective and prospective childhood adversity measures are predictive of health outcomes, they may not be used interchangeably because of the poor-to-fair agreement between these two measures. Using either prospective or retrospective adversity measures, he also identified parental emotional support in adolescence, but not in adulthood, as a significant stress-buffering process.

(C) Resilience to social stress and adversity

The third essential thread of his recent work focuses on exploring resilience mechanisms and developing intervention models to prevent or attenuate the impacts of adversity on well-being. Past research has largely ignored the potential indirect moderation role of intervention. He proposed an indirect moderation model to examine an intervention-induced change in family processes as moderators of the erosive effect of neighborhood disadvantage, thereby more stringently testing their causal role in creating resilience. His research also replicated previous work on the erosive effects of discrimination on Black youth's depressive symptoms. He showed that change in protective parenting behavior produced by family-based interventions exerted a protective, buffering effect. These findings highlight the potential of family-based interventions to promote constructed resilience resources that can, in turn, protect marginalized people in the face of discrimination and disadvantage. In addition to understanding family resilience mechanisms, his recent study reviewed the neighborhood resilience literature. He found that resilience is a moderated-mediation mechanism and can occur at various levels, ranging from individual to neighborhood. This review paper proposes a multilevel structural resilience model that identifies three resilience pathways: (a) resilience as a mediator of social context and individual well-being; (b) resilience as a buffering mechanism that protects individuals from disadvantage; and (c) resilience as a moderated mediation mechanism that is both influenced by neighborhood context and, in turn, prevents stress and disadvantaged effect.

  • Ph.D., Sociology, University of Georgia, 2013
  • M.A., Sociology, University of Georgia, 2010
  • M.A., Sociology, National Taiwan University, 2001
  • LL.B., Law (minor in Sociology), National Taiwan University, 1999
  • 2020. Principal Investigator, Teaming for Interdisciplinary Research Program Award, Office of Research, University of Georgia.
  • 2019-2021. Co-Investigator, “Childhood Stressors and Cardiovascular Disease Risk in Adulthood: A Longitudinal Investigation of Divergent Explanatory Models.” Centers for Disease Control and Prevention. 
  • 2018-2023. Co-Investigator, "Using a Randomized Prevention Trial to Understand the Health Benefits of Supportive Couple Relationships among Rural African American Adults," National Institute on Aging.
  • 2017-2022. Co-Investigator, "Psychosocial Context and the Biological Clock: Changes in Weathering during Middle Age," National Institute on Aging.
Selected Publications:
  1. Lei, Man-Kit, Justin A. Lavner, Sierra E. Carter, Olutosin Adesogan, and Steven R. H. Beach. Forthcoming. “Relationship Intervention Indirectly Buffers Financial Strain's Effect on Biological Aging Among Black Adults.” Journal of Family Psychology. DOI: 10.1037/fam0000926. Selected Media Coverage: APA Research Briefs 
  2. Lei, Man-Kit, Gene H. Brody, and Steven R. H. Beach. Forthcoming. “Intervention Effects on Self-Control Decreases Speed of Biological Aging Mediated by Changes in Substance Use: A Longitudinal Study of African American Youth.” Family Process. DOI: 10.1111/famp.12715
  3. Lei, Man-Kit, Mark T. Berg, Ronald L. Simons., and Steven R. H. Beach. 2022. “Neighborhood Structural Disadvantage and Biological Aging in a Sample of Black Middle Age and Young Adults.” Social Science & Medicine  293: 114654.
  4. Lei, Man-Kit, Steven R. H. Beach, Ronald L. Simons, and Kaixiong Ye. 2021. “The Impact of Harsh Parenting on the Development of Obesity in Adulthood: An Examination of Epigenetic/Gene Expression Mediators among African American Youth.” Frontiers in Cardiovascular Medicine 8: 755458.
  5. Lei, Man-Kit, Justin A. Lavner, Sierra E. Carter, Ariel R. Hart, and Steven R. H. Beach. 2021. “Protective Parenting Behavior Buffers the Impact of Racial Discrimination on Depression among Black Youth.” Journal of Family Psychology 35: 457-467.
  6. Lei, Man-Kit and Ronald L. Simons. 2021. “The Association between Neighborhood Disorder and Health: Exploring the Moderating Role of Genotype and Marriage." International Journal of Environmental Research and Public Health 18: 898.
  7. Lei, Man-Kit and Steven R. H. Beach. 2020. “Can We Uncouple Neighborhood Disadvantage and Delinquent Behaviors?  An Experimental Test of Family Resilience Guided by the Social Disorganization Theory of Delinquent Behaviors.Family Process 59: 1801-1817.
  8. Lei, Man-Kit and Ronald L. Simons. 2020. “A Multilevel Structural Resilience Model: When and For Whom do Neighborhoods Really Matter?International Sociological Association eSymposium for Sociology 30: 1-12.
  9. Lei, Man-Kit and Eric T. Klopack. 2020. “Social and Psychological Consequences of the COVID-19 Outbreak: The Experiences of Taiwan and Hong KongPsychological Trauma: Theory, Research, Practice, and Policy 12(S1): S35-S37. Selected Media Coverage: Psychology Today 
  10. Lei, Man-Kit, Frederick X. Gibbons, Ronald L. Simons, Robert A. Philibert, and Steven R. H. Beach. 2020. “The Effect of Tobacco Smoking Differs Across Indices of DNA Methylation-Based Aging in an African American Sample: DNA Methylation-Based Indices of Smoking Capture These Effects.” Genes 11: 311.
  11. Lei, Man-Kit, Mark T. Berg, Ronald L. Simons., Leslie G. Simons, and Steven R. H. Beach. 2020. “Childhood Adversity and Cardiovascular Disease Risk: An Appraisal of Recall Methods with a Focus on Stress-Buffering Processes in Childhood and Adulthood.Social Science & Medicine 246: 112794.
  12. Lei, Man-Kit, Ronald L. Simons, Steven R.H. Beach, and Robert A. Philibert. 2019. "Neighborhood Disadvantage and Biological Aging: Using Marginal Structural Models to assess the Link between Neighborhood Census Variables and Epigenetic Aging." Journals of Gerontology: Social Sciences 74: e50-e59.
  13. Lei, Man-Kit, Steven R.H. Beach, and Ronald L. Simons. 2018. "Biological Embedding of Neighborhood Disadvantage and Collective Efficacy: Influences on Chronic Illness via Accelerated Cardiometabolic Age." Development and Psychopathology 30: 1797-1815.
  14. Lei, Man-Kit, Steven R.H. Beach, and Ronald L. Simons. 2018. "Childhood Trauma, Pubertal Timing, and Cardiovascular Risk in Adulthood." Health Psychology 37: 613-617.
  15. Lei, Man-Kit, Steven R.H. Beach, Meeshanthini V.  Dogan, and Robert A. Philibert. 2017. "A Pilot Investigation of the Impact of Smoking Cessation on Biological Age." American Journal on Addictions 26: 129-135.
  16. Lei, Man-Kit, Steven R.H. Beach, Ronald L. Simons, Ashley B. Barr, Carolyn E. Cutrona, and Robert A. Philibert. 2016. “Stress, Relationship Satisfaction, and Health among African American Women: Genetic Moderation of Effects.” Journal of Family Psychology 30: 221-232.
  17. Lei, Man-Kit, Steven R.H.  Beach, Ronald L. Simons, and Robert A. Philibert. 2015. "Neighborhood Crime Scale" [Database record]. APA PsycTests.
  18. Lei, Man-Kit, Steven R.H.  Beach, Ronald L. Simons, and Robert A. Philibert. 2015. “Neighborhood Crime and Depressive Symptoms among African American Women: Genetic Moderation and Epigenetic Mediation of Effects.” Social Science & Medicine 146: 120-128.
  19. Lei, Man-Kit, Ronald L. Simons, Mary Bond Edmond, Leslie Gordon Simons, and Carolyn E. Cutrona. 2014. “The Effect of Neighborhood Disadvantage, Social Ties, and Genetic Variation on the Antisocial Behavior of African American Women: A Multilevel Analysis.” Development and Psychopathology 26: 1113-1128.
  20. Lei, Man-Kit, Ronald L. Simons, Leslie Gordon Simons, and Mary Bond Edmond. 2014. “Gender Equality and Violent Behavior: How Neighborhood Gender Equality Influences the Gender Gap in Violence.” Violence and Victims 29: 89-108.
Of Note:


  • 2022. Donal MacNamara Award, Academy of Criminal Justice Sciences
  • 2014. B. O. Williams Award for Dissertation Research, Department of Sociology, University of Georgia.
  • 2013. Joan Petersilia Outstanding Article Award, American Society of Criminology.
  • 2013. Certificate of Excellence, Department of Sociology, University of Georgia.
  • 2012. First Prize, Gene Carte Student Paper Award, American Society of Criminology.
  • 2012. The Best Graduate Student Paper Award, Evolution, Biology & Society Section, American Sociological Association.
  • 2011.  B. O. Williams Award for Thesis Research, Department of Sociology, University of Georgia.

Elected Offices and Editorial Experience

  • 2021-present. Associate Editor, Frontiers in Cardiovascular Medicine (IF = 6.050)
  • 2021-2022. Guest Editor, Special Issue of International Journal of Environmental Research and Public Health on “Life and Health of the Elderly” (IF = 3.390)
Courses Regularly Taught:
Articles Featuring Man Kit Lei
Tuesday, January 4, 2022 - 2:40pm

Man-Kit (Karlo) Lei received the Charles B. Knapp Early Career Scholar Award from the Office of Research in recognition of his outstanding research accomplishments.