My research program is driven by a general interest in understanding how and why early life environments shape patterns of human biology and health.
RESEARCH THEMES
Developmental plasticity, evolution, and health
The focus of this research is on understanding the short and long term effects of maternal stress in the perinatal period, as indexed by various psychological indicators and maternal cortisol levels, on offspring health and well-being. This research is important because it shifts attention away from only focusing on health behaviors in adulthood and instead highlights how early life environmental experience can have important impacts on health in adulthood. Most recently we have been trying to understand how timing and duration of stress experience across developmental periods may differentially affect offspring phenotype, as well as how similar physiological systems are programmed in other species.
A subset of this work addresses how developmental plasticity and evolutionary biology can inform the design of public health interventions to improve maternal and child health. As an example, my colleagues and I argued in a recent EMPH piece that short-term macronutrient interventions in pregnancy are unlikely to result in large impacts on offspring phenotype since offspring have evolved to be sensitive to long term signals of maternal environmental experience. Consequently nutritional interventions need to be longer in duration and/or target critical periods of maternal development in order to have increased efficacy. More recently I argued that fetal sensitivity to psychosocial stress could contribute to the development of low birth weight among children conceived through Assisted Reproductive Technologies. The implications of this work is that mental health support should be offered alongside ART therapies and could help to improve outcomes.
Select publications in this area are highlighted below:
- Uwizeye, G., Rutherford, J. N., & Thayer, Z. 2023. Associations between duration of first trimester intrauterine exposure to genocide against the Tutsi and health outcomes in adulthood. American journal of biological anthropology.
- Uwizeye, G., Thayer, Z. M., DeVon, H. A., McCreary, L. L., McDade, T. W., Mukamana, D., … & Rutherford, J. N. 2021. Double Jeopardy: Young adult mental and physical health outcomes following conception via genocidal rape during the 1994 genocide against the Tutsi in Rwanda. Social Science & Medicine, 278, 113938.
- Thayer, Z. Assisted Reproductive Technology, psychosocial stress, and low birth weight. Evolution, Medicine and Public Health. 2020: 82–83
- Thayer, Z, Rutherford, J., and Kuzawa, C. The Maternal Nutritional Buffering Model: An evolutionary framework for pregnancy nutritional intervention. Evolution, Medicine and Public Health, 2020: 14-27.
- Thayer, Z., and C. Sweetman. Intergenerational Effects: How maternal adversity impacts offspring. Elife 8 (2019): e51206.
- Thayer, Z., Wilson, M., Kim, A., & Jaeggi, A. Impact of prenatal stress on offspring glucocorticoid levels: A phylogenetic meta-analysis across 14 vertebrate species. Scientific Reports, 2018: 8(1). doi:10.1038/s41598-018-23169-w
- Thayer, Z. Developmental adaptation. In The International Encyclopedia of Biological Anthropology 2018. (eds W. Trevathan, M. Cartmill, D. Dufour, C. Larsen, D. O?Rourke, K. Rosenberg and K. Strier). doi:10.1002/9781118584538.ieba0132
- Thayer, Z., Barbosa-Leiker, C., McDonell, M., Nelson, L., Buchwald, D., and S. Manson. Early life stress, post-traumatic stress disorder, and allostatic load in a sample of American Indian adults. American Journal of Human Biology, 2017 29(3): e22943
Minority health and health inequities
Human biology methods can be used to better understand how social inequalities create health inequalities within and between socially defined ethnic groups. As an example, during my dissertation research I documented that maternal experience of ethnic discrimination predicts variation in stress physiology of offspring. Since stress physiology influences the functioning of many other physiological systems important for health, this research suggests that individuals may be predisposed to poor health due to ethnic discrimination experienced by their mothers. Consistent with this, my collaborators and I recently found that indigenous Māori women who reported discrimination experience before or during pregnancy subsequently gave birth to infants an average of one week earlier and more than 200 grams lighter when compared to Māori women who did not report a similar discrimination experience. We published an article reporting that discrimination experience in this cohort is also associated with shorter telomere length in children at four years of age.
Collaborators and I have also published articles exploring the impact of early trauma and discrimination on Native American health in the United States. For example, we reported that early life trauma, when combined with subsequent development of post traumatic stress disorder, was associated with significantly higher allostatic load in adulthood among a sample of American Indian adults from reservation communities in the Northern Plains. In addition, racial discrimination experience in adulthood was associated with higher blood pressure in the same cohort. Using data from individuals from tribal communities in both the Southwest and Northern Plains, we were the first to report that individual as well as paternal experience of Native American residential boarding experience is associated with significantly poorer health in adulthood.
Finally, I am interested in contributing to theory around understanding how social inequalities create health inequalities. As an example, I co-authored several papers describing how acculturative stress can impact maternal and child health. In addition, in 2019 I co-authored a manuscript with a Dartmouth student that described the biological pathways through which historical trauma could affect health. Building on previous work, we argue that both within- and between- generation effects of trauma could contribute to the development of poor health through impacts on stress physiology systems and the epigenome.
Select publications in this area are highlighted below:
- Thayer, Z., Becares, L., Marks, E., Ly, K., & Walker, C. 2023. Maternal racism experience and cultural identity in relation to offspring telomere length. Scientific Reports, 13(1), 10458.
- Thayer, Z, Uwizeye, G & McKerracher, L. 2022. “Toolkit article: Approaches to measuring social inequities in health in human biology research.” American Journal of Human Biology 34.12: e23804.
- Robbins, N. M., Charleston, L., Saadi, A., Thayer, Z., Codrington, W. U., Landry, A., … & Hamilton, R. 2022. Black Patients Matter in Neurology: Race, Racism, and Race-Based Neurodisparities. Neurology, 99(3), 106-114.
- Salas, L. A., Peres, L. C., Thayer, Z., Smith, R. W., Guo, Y., Chung, W., … & Liang, L. 2021. A transdisciplinary approach to understand the epigenetic basis of race/ethnicity health disparities. Epigenomics, 13(21), 1761-1770.
- Thayer, Z, Becares, L, Atatoa Carr, P. Maternal experiences of ethnic discrimination and subsequent birth outcomes in Aotearoa New Zealand. BMC Public Health 2019: 19(1): 1271-1279.
- Conching, A., and Z. Thayer. Biological pathways for historical trauma to affect health: a conceptual model focusing on epigenetic modifications. Social Science and Medicine 2019 230: 74-82.
- Running Bear, U., Thayer, Z., Croy, C., Kaufman, C., & Manson, S. The impact of individual and parental American Indian boarding school attendance on chronic physical health of Northern Plains Tribes. Family & Community Health 2019 42(1): 1-7.
- Running Bear U, Croy CD, Kaufman CE, Thayer Z, Manson SM; AI-SUPERPFP Team. The relationship of five boarding school experiences and physical health status among Northern Plains Tribes. Quality Life Research 2018;27(1):153-157. doi:10.1007/s11136-017-1742-y
- Thayer, Z., Blair, I., Buchwald, D., and S. Manson. Racial discrimination associated with higher diastolic blood pressure in a sample of American Indian adults. American Journal Physical Anthropology 2017: 163(1): 122–128.
- Fox M, Thayer Z, Wadhwa PD. Acculturation and health: the moderating role of socio-cultural context. American Anthropologist. 2017;119(3):405-421. doi:10.1111/aman.12867
- Fox M, Thayer Z, Wadhwa PD. Assessment of acculturation in minority health research. Social Science & Medicine 2017 Mar;176:123-132. DOI: 10.1016/j.socscimed.2017.01.029.
- Thayer, Z, and C. Kuzawa. Ethnic discrimination predicts poor self-rated health and cortisol in pregnancy: Insights from New Zealand. Social Science and Medicine. 2015: 128(0), 36-42.
Social factors shaping maternal health and well-being
Building off of a longstanding interest in the impacts of maternal well-being on offspring growth and development, my most recent projects focus on understanding social and cultural factors that shape maternal well-being in pregnancy, childbirth, and the postpartum period. Recognizing the impacts of the COVID-19 pandemic on maternity care and delivery experiences, Dr. Theresa Gildner (Postdoctoral fellow at Dartmouth College) and I launched the COVID-19 and Reproductive Effects (CARE) study. We have published and currently have in review a series of articles that consider how the pandemic has shaped women’s experiences in prenatal care and delivery, and consequent impacts on maternal mental health and ultimately on offspring health as well.
One article, reviewed in the New York Times, explored the relationship between childbirth fear and preterm birth. We argue that childbirth fear is a presently underappreciated source of anxiety for pregnant people in the United States, and that the COVID-19 pandemic exacerbated these fears. There were socioeconomic and racial inequities in the experience of childbirth fear, suggesting that this may be a presently underappreciated contributor to adverse birth outcomes.
Select publications in this area are highlighted below:
- Thayer, Z., Geisel-Zamora, S. A., Uwizeye, G., & Gildner, T. E. 2023. Childbirth fear in the USA during the COVID-19 pandemic: key predictors and associated birth outcomes. Evolution, Medicine, and Public Health, 11(1), 101-111.
- Thayer, Z., & Gildner, T. 2023. Reported information sharing and satisfaction with maternity care providers during the COVID‐19 pandemic: Associations with socioeconomic status and shifts to telehealth. Birth, 50(2), 396-406.
- Gildner, T. & Thayer, Z. 2020. Maternal and child health during the COVID-19
pandemic: Contributions in the field of human biology. American Journal of Human Biology - Gildner, T. & Thayer, Z. 2020. Birth plan alterations among American women in
response to COVID-19. Health Expectations - Thayer, Z. 2020. U.S. Coronavirus advice is failing pregnancy women. Sapiens Anthropology Magazine.
- S. Montgomery & Z. Thayer. 2020. The Influence of Experiential Knowledge and Societal Perceptions on Decision-Making Regarding Non-Invasive Prenatal Testing (NIPT). BMC Pregnancy and Childbirth.