» Dr. Jennifer A. Hahn-Holbrook
Assistant Professor

Crean College of Health and Behavioral Sciences
Department of Psychology
Dr. Jennifer A. Hahn-Holbrook
Office Location:
Crean Hall 106 ( 501 W. Palm Ave )
(714) 289-2061
University of California, Santa Cruz, Bachelor of Arts
Queen's University Belfast, Ph.D.

After obtaining my PhD overseas in Northern Ireland, I came back to the USA and did a postdoctoral fellowship at UCLA’s world renowned Health Psychology Program with mentors Martie Haselton and Chris Dunkel Schetter. There, I studied the effects of breastfeeding on maternal depression and learned advanced statical skills that enabled me to put together a biopsychosocial model of postpartum depression. I originally hail from the San Jose area, and come from a long line of Californians. I could not be happier teaching and doing research at Chapman. I live with my husband and fellow researcher, Colin Holbrook, and our two Pomeranians, Jigsaw and Lily.


  • PSY 204: Research Methods in Behavioral Sciences
  • PSY 436: Health Psychology

Research Summary:

Research in my laboratory explores the interplay between the psychological and biological processes that shape maternal mental and physical health.  My interdisciplinary training in evolutionary, biological, and health psychology informs my research in the following three domains of focus: (1) the psychological impacts of biological changes surrounding pregnancy and breastfeeding, (2) the role of stress and maternal resources in both bolstering or undermining maternal behaviors and health, and (3) the evolutionary origins of maternal behaviors and mental health disorders. See the descriptions of several ongoing projects below:

Does breastfeeding help to shape the maternal mind?

My lab studies the mental and physical health consequences of breastfeeding for mothers.  For example, my colleagues and I recently found a bidirectional association between breastfeeding and postpartum depression (Hahn-Holbrook, Glynn, Haselton, & Dunkel Schetter, 2013).  On the one hand,  women who were depressed during pregnancy were less likely to breastfeed; on the other, women who engaged in more frequent breastfeeding were somewhat protected against depressive symptoms postpartum. We are currently running an experimental lab study to investigate how hormonal changes surrounding breastfeeding influence a mother’s mood, attachment, aggression, and attention towards a range of stimuli.

Do social factors like family support or support from the baby’s father influence the mother’s hormonal changes during pregnancy?

We recently found that social support from family during mid-pregnancy was protective against depressive symptoms postpartum, in part, because family support buffered mothers against deleterious increases in the stress hormone placental corticotrophin releasing hormone (pCRH) during late pregnancy (Hahn-Holbrook et al.,2013). This finding represents an important step forward in our understanding of postpartum depression because it illuminates why some women experience more dramatic increases in pCRH during pregnancy, raising their risk for postpartum depression. This work also helps us understand how social processes get “under the skin” to provide protection against complex mental illnesses such as postpartum depression. Our work in this area is ongoing and we are currently trying to build additional biopsychosocial models of postpartum depression and preterm birth.

Is postpartum depression a disease of modern civilization?

Postpartum depression poses an evolutionary puzzle: it is extremely common, yet significantly reduces the reproductive fitness of both mothers and offspring. Why has natural selection failed to remove this trait? My lab is currently developing and testing the hypothesis that postpartum depression represents a “disease of modern civilization” and is caused by the dramatic cultural changes to motherhood that have occurred over the last century. This “Discontinuity Hypothesis” predicts that postpartum depression will be more common in contexts in which breastfeeding, diet, exercise, sleep, & alloparenting patterns diverge dramatically from those of our Pleistocene ancestors. We are currently conducting cross-cultural and longitudinal studies to test this hypothesis.  


Recent Creative, Scholarly Work and Publications
Fessler, D.M.T., Holbrook, C., Pollack, J., & Hahn-Holbrook, J. (2014). Stranger danger: Parenthood and child presence increase the envisioned bodily formidability of menacing men. Evolution and Human Behavior, 35, 109-117.
Hahn-Holbrook, J. & Haselton, M. (in press). Is postpartum depression a disease of modern civilization? Current Directions in Psychological Science.
Yim, I., Tanner, L., Guardino, C., Hahn-Holbrook, J., & Dunkel Schetter, C. (in press). Biological and psychosocial predictors of postpartum depression: Systematic review and call for integration. Annual Review of Clinical Psychology.
Hahn-Holbrook, J., Dunkel Schetter, C., Chander, A., & Hobel, C. (2013). Placental corticotropin-releasing hormone mediates the association between prenatal social support and postpartum depression. Clinical Psychological Science, 1, 253-265.
Hahn-Holbrook, J., Glynn, L., Haselton, M., & Dunkel Schetter, C. (2013). Does breastfeeding offer protection against maternal depressive symptomatology? A prospective study from pregnancy to two years after birth. Archives of Women’s Mental Health, 16, 411-422.
Hahn-Holbrook, J., Dunkel Schetter, C., & Haselton, M. (2013). The advantages and disadvantages of breastfeeding for maternal mental and physical health (pp. 414-439). In M. Spiers, P. Geller & J. Kloss (Eds.). Women’s Health Psychology. New Jersey: Wiley.
Hahn-Holbrook, J., Holt-Lunstad, J., Holbrook, C., Coyne, S.M., & Lawson, T. (2011). Maternal defense: Breastfeeding heightens aggression by reducing stress. Psychological Science, 22, 1288-1295. doi: 10.1177/0956797611420729
Hahn-Holbrook, J., Holbrook, C., & Haselton, M. (2011). Parental precaution: Neurobiological means and adaptive ends. Neuroscience and Biobehavioral Reviews, 35, 1052-1066. doi:10.1016/j.physletb.2003.10.071
Holbrook, C., Sousa, P., & Hahn-Holbrook, J. (2011). Unconscious vigilance: Worldview defense without adaptations for terror, coalition or uncertainty management. Journal of Personality and Social Psychology, 101, 451-466. doi: 10.1037/a0024033
Hahn-Holbrook, J., Holbrook, C., & Bering, J. (2010). Snakes, spiders, strangers: How the evolved fear of strangers may misdirect efforts to protect children from harm. In J. M. Lampinen & K. Sexton-Radek (Eds.), Protecting children from violence: Evidence based interventions. New York: Psychology Press.