I examine reproductive decision-making in a variety of ways. My dissertation research examined decisions made by women in San Borja, Bolivia. Since then, I have shifted my research to examine how and why predictors of fertility outcomes vary cross-culturally. A recent research project (with Dr. Heidi Colleran) examined how predictors of fertility varied across 45 countries represented in the Demographic and Health Surveys. The results show that some factors are quite consistent, like education, which is always negatively associated with fertility, while others are variable, such as wealth, which tends to be positively correlated with fertility in high-fertility countries, but negatively correlated with fertility in low-fertility countries (after controlling for education). This research helps elucidate the psychological mechanisms that may be influencing human reproductive decision-making.
Colleran, H., Snopkowski, K. (2018) Variation in wealth and educational drivers of fertility decline across 45 countries. Population Ecology, 60: 155-159
Snopkowski, K., Towner, M., Shenk, M., Colleran, H. (2016) Pathways from education to fertility decline: a multi-site comparative study. Philosophical Transactions B, 371: 20150156.
Snopkowski, K., Kaplan, H. (2014) A Synthetic Biosocial Model of Fertility Transition: Testing the Relative Contribution of Embodied Capital Theory, Changing Cultural Norms, and Women’s Labor Force Participation. American Journal of Physical Anthropology, 154(3): 322-333.
I also examine kin cooperation and conflict (including partner conflict) to understand reproductive outcomes and the evolution of menopause. I seek to understand why empirical results tend to show that maternal kin (particularly grandmothers) have a negative or null effect on fertility outcomes, while paternal grandmothers have a positive effect on fertility outcomes. I have also tested the intergenerational conflict model, which predicts that reproductive senescence in humans may be the result of intergenerational conflict between mothers-in-law and their daughters-in-law (with Drs. Cristina Moya and Rebecca Sear). The role of male partners is another important component of reproductive decision-making. I explore how preferences within couples for future reproduction varies by men and women and how those conflicts are resolved to understand another key piece of reproductive decision-making.
Snopkowski, K. Nelson, J.J. (2021) Fertility intentions and outcomes in Indonesia: Evolutionary perspectives on sexual conflict. Evolutionary Human Sciences, 3:e33
Moya, C., Snopkowski, K., Sear, R. (2016) What do men want? Re-examining whether men benefit from higher fertility than is optimal for women. Philosophical Transactions B, 371: 20150149.
Snopkowski, K., Sear, R. (2016) Does grandparental help mediate the relationship between kin presence and fertility? Demographic Research, 34 (17): 467-498.
Snopkowski, K., Sear, R. (2015) Grandparental help in Indonesia is directed preferentially towards needier descendants: A potential confounder when exploring grandparental influences on child health. Social Science & Medicine, 128: 105-114.
Snopkowski, K., Moya, C., Sear, R. (2014) A test of the intergenerational conflict model in Indonesia shows no evidence of earlier menopause in female-dispersing groups. Proceedings of the Royal Society B: Biological Sciences, 281(1788): 20140580
The project, "Educational Outcomes for African Refugee Youth: A Longitudinal Study of Stress and Protective Factors" with collaborators Drs. April Masarik and Kathryn Demps examines stress pathways and protective factors related to refugee resettlement for African refugee youth. We examine psychological and physiological factors (specifically, cortisol) and their relation to educational outcomes by collecting longitudinal data from African refugee youth and their families living in Boise, Idaho. We are collaborating with interpreters, translators, the International Rescue Committee, and the Agency for New Americans. This project has been funded by the Osher Lifelong Learning Institute and the Spencer Foundation.
Interviewed for Boise State Public Radio (2019) How Does Psychological Stress Affect Refugees? Boise State Researchers Answer (with Dr. April Masarik and Salome Mwangi)
Boise State Explore Magazine (2019) Interdisciplinary team studies the stress and resiliency of local refugee students (with Dr. April Masarik, Salome Mwangi, and Dr. Kathryn Demps)
In a collaboration with Dr. John Ziker, who was funded for a Fulbright Scholar Distinguished Chair in Brain Sciences and Family Wellness grant, we examined the National Longitudinal Survey of Children and Youth, a large-scale longitudinal survey of Canadian youth to examine how early-life stressors and prenatal factors influence sexual initiation and suicidal ideation in adolescence. This research utilized a model selection approach to identify which sets of predictors (e.g., psychosocial stress, social support, prenatal factors) best predicted adolescent outcomes. Many factors influenced sexual debut, including mortality cues, intergenerational conflict, and early life psychosocial stressors. In contrast, social support and early life psychosocial stressors were most important in predicting suicidal ideation.
Snopkowski, K., Ziker, J. (2020) Sexual Initiation Among Canadian Youth: A model comparison approach of evolutionary hypotheses shows greatest support for extrinsic mortality cues, intergenerational conflict, and early life psychosocial stressors. Evolution and Human Behavior, 41(2): 105-116.
Ziker, J. Snopkowski, K. (2020) Life-history factors influence teenagers’ thoughts of suicide: A model selection analysis of the Canadian National Longitudinal Survey of Children and Youth. Evolutionary Psychology, July-September: 1-17.