• Stacy Rosenbaum

    Postdoctoral Fellow | Northwestern University

    I am a biological anthropologist studying the evolution and physiology of social behavior. Currently, I am a Postdoctoral Research Associate in the Department of Biological Sciences at University of Notre Dame. I previously held postdoctoral fellowships in the Department of Anthropology at Northwestern University, and at the University of Chicago's Institute for Mind and Biology. I earned my PhD at UCLA.


    My empirical work to date has primarily focused on a wild population of mountain gorillas in the Great Lakes region of Africa. This population has been monitored for 50 years, which provides unparalleled opportunities to understand how variation in ecological and social environments influences reproductive success and life history patterns in a long-lived mammal. I use behavioral, genetic, and hormonal data to determine how kin discrimination, behavioral plasticity, and life history decisions interact to produce the astonishing range of variation observed in these animals’ social group structures and social relationships. The goal of my research is to gain a richer understanding of the evolution of mammalian sociality generally, and the hominid lineage specifically.


    In addition to my research on gorillas, I also work on complementary research questions about primate evolution, sociality and health, using the Cebu Longitudinal Health and Nutrition Survey (humans), and data collected for the Amboseli Baboon Project (yellow and anubis baboons), via collaborations with Dr. Christopher Kuzawa and Dr. Beth Archie.


    You can find an up-to-date copy of my CV here.

  • Research

    Social behavior

    Humans and many other animals develop myriad social relationships across the course of their lifetimes. I study how these relationships develop and are maintained, what their consequences are for participants, and how individual relationships impact evolutionary dynamics.


    Social relationships have many physiological correlates. For example, hormones and social behavior work in complex feedback loops. I study how relationships and physiology impact one another, and how their interactions affect health, longevity, and reproductive success.

    Methods development

    Studying wild primates, especially critically endangered species, comes with many methodological challenges. I work on improving existing tools, and developing new ones, to non-invasively measure a variety of physiological parameters.

  • Publications

    Peer Reviewed Publications

    Rosenbaum S, Vigilant L, Kuzawa CW, & Stoinski TS (2018). Caring for infants is associated with increased reproductive success for male mountain gorillas. Scientific Reports, 8:15223.


    Rosenbaum S, Gettler LT, McDade T, Augustin S, & Kuzawa CW (2018). Does men’s testosterone ‘rebound’ when dependent children grow up, or when pair bonds end? A test in Cebu, Philippines. American Journal of Human Biology, e23180.


    Rosenbaum S, Gettler LT, McDade TW, Belarmino NM, & Kuzawa CW (2018). The effects of collection and storage conditions in the field on salivary testosterone, cortisol, and sIgA. Annals of Human Biology, DOI: 10.1080/03014460.2018.1495263.


    Rosenbaum S & Gettler LT (2018). With a little help from her friends (and family) I: the ecology and evolution of non-maternal caretaking in mammals. Physiology & Behavior, 193, 1-11.


    Rosenbaum S & Gettler LT (2018). With a little help from her friends (and family) II: the behavior and physiology of non-maternal caretaking in mammals. Physiology & Behavior, 193, 2-24.


    Gettler LT, Kuo P, Rosenbaum S, Avila J, McDade T, & Kuzawa CW (2018). Sociosexuality, testosterone, and life history status: prospective associations and longitudinal changes among men in Cebu, Philippines. Evolution and Human Behavior, DOI: 10.1016/j.evolhumbehav.2018.11.001.


    Rosenbaum S, Vecellio V, & Stoinski TS (2016). Observations of severe and lethal coalitionary attacks in wild mountain gorillas. Scientific Reports, 6, 37018.


    Eckardt W, Stoinski TS, Rosenbaum S, Umuhoza MR, & Santymire R (2016). Characterizing stress physiology in Virunga mountain gorillas. Conservation Physiology, 4, cow029.


    Rosenbaum S, Hirwa JP, Silk JB, Vigilant L, & Stoinski TS (2016). Infant mortality risk and paternity certainty are associated with postnatal maternal behavior toward adult male mountain gorillas. PLoS One, DOI: 10.1371/journal.pone.0147441.


    Rosenbaum S, Hirwa JP, Silk JB, & Stoinski TS (2016). Relationships between adult male and maturing mountain gorillas persist across developmental stages and social upheaval. Ethology, 122, 134-150.


    Rosenbaum S, Maldonado-Chapparo AA, & Stoinski TS (2015). Group structure predicts variation in proximity relationships between male-female and male-infant pairs of mountain gorillas. Primates, 57, 17-28.


    Rosenbaum S, Hirwa JP, Silk JB, Vigilant L, & Stoinski TS (2015). Male rank, not paternity, predicts male-immature relationships in mountain gorillas. Animal Behaviour, 104, 13-24.


    Rosenbaum S, Silk JB, & Stoinski TS (2011). Male-immature relationships in multi-male groups of mountain gorillas. American Journal of Primatology, 71, 1-10.


    Stoinski TS, Rosenbaum S, Ngaboyamahina T, Vecellio V, Ndagijimana F, & Fawcett K (2009). Patterns of male reproductive behavior in multimale groups of mountain gorillas: examining theories of reproductive skew. Behaviour, 146, 1193-1215.


    Stoinski TS, Vecellio V, Ngaboyamahina T, Ndagijimana F, Rosenbaum S, & Fawcett K (2009). Proximate factors influencing dispersal decisions in male mountain gorillas. Animal Behaviour 77, 1155-1164.

    Under Review

    Rosenbaum S, Eckardt W, Stoinski TS, Kuzawa CW, & Santymire RS (under review). Validation of an androgen enzyme immunoassay as a measure of fecal testosterone and 5a-dihydrotestosterone metabolites in wild male mountain gorillas (Gorilla beringei)


    Eckardt W, Stoinski TS, Rosenbaum S, & Santymire RS (under review). Social and ecological factors negatively affect the stress physiology of Virunga mountain gorillas.

    Other Publications

    Rosenbaum S, Stoinski TS, & Santymire R. Urinary androgens, dominance hierarchies, and social group structure among wild male mountain gorillas. In Chimpanzees in context: a comparative perspective on behavior, cognition, conservation, and welfare (Hopper L & Ross S, eds.). University of Chicago Press. Book in press, anticipated 2019.


    Rosenbaum S (2018). Offspring defense. In Encyclopedia of Evolutionary Psychological Science (Shackelford TK & Weekes-Shackelford VA, eds.). Springer. DOI: 10.1007/978-3-319-16999-6_1904-1.

  • Current projects

    Special theme issue of Physiology & Behavior: non-maternal caretaking in mammals

    In most mammal species, only mothers care for young. However the exceptions, including humans, are of particular theoretical importance for our understanding of the evolution of sociality and of reproductive strategies. Lee Gettler and I are co-guest editing a special journal issue on the physiology and behavior of non-maternal caretaking in mammals, to be published in mid 2018. The issue will contain a wide variety of empirical, theoretical, and review/synthesis papers from diverse fields, including psychology, anthropology, and neurobiology.


    Update: it's out! You can find the link to the full issue here.


    Evolutionary perspectives on non-maternal care in mammals: physiology, behavior, and developmental effects. Physiology and Behavior, Edited by Stacy Rosenbaum & Lee T Gettler Volume 193, Part A, Pages 1-186

    Hormonal correlates of reproductive strategies in humans

    The combination of slow life histories, complex social structures, and extensive non-maternal care make reproductive tradeoffs particularly complex in humans. Physiological correlates of our mating and parenting behaviors hold important clues to the evolutionary origins of human pair bonding, biparental care, and cooperative care. Colleagues Chris Kuzawa, Lee Gettler, and I are exploring (for example) what happens to men's testosterone levels as their relationship status and the nature of their parental investment(s) change over time, and if/how alloparental caretakers affect these patterns. The results, especially when viewed in the wider context of comparative work on other mammals, provide important insights about the evolution of human males' exceptional investment in parenting.

    Ecological and social predictors of stress and sex hormones in Gorilla beringei

    Mountain gorillas live in complex social groups whose structure can vary dramatically. They are also a rare conservation success story, which means the growing population is experiencing increased inter-group contact and expanding into previously unused habitat. Both the short-term variation and long-term changes have important implications for the health of individual animals, as well as the population. Tara Stoinski, Winnie Eckardt, Rachel Santymire and I are examining how changing social and ecological environments affect the gorillas' steroid hormone profiles, and how those profiles relate to individual differences in reproductive and health outcomes.

    Life history timing in Gorilla beringei

    Published genetic paternity data, plus preliminary hormone metabolite data, suggest that male mountain gorillas may have accelerated life history timing relative to other great apes. We are curating various biomaterials (e.g. serum and hair) from captive gorilla populations in the United States, to study the timing of sexual maturation in male gorillas. Results have important implications for understanding the range of reproductive strategies used by male hominids, as well as potential uses in captive animal management.

    Non-invasive body composition measurement in great apes

    Even though measures of body composition (i.e. the ratio of lean tissue to adipose tissue) are crucial to answering a host of questions about development, health, competitive ability, and reproductive potential, field scientists rarely use them because of the difficulty of measurement in wild animals. Building on the work of Melissa Emery-Thompson and colleagues, we are directly validating a body composition measurement technique that relies solely on urine. The long-term goal is to build predictive equations that field scientists can use to estimate body composition in each of the four great ape species easily, cheaply, and accurately. Herman Pontzer is a collaborator on this project.

    Hormone metabolite identification using HPLC/MS

    Non-invasive endocrine analyses require measuring hormone metabolites, rather than native hormone. There are many biological and laboratory validations required to be certain that the measured metabolite accurately reflects the hormone(s) of interest. Working with colleagues at the Feinberg School of Medicine and the Smithsonian Conservation Biology Institute, we are developing a protocol to isolate and identify metabolites of interest in hormone samples obtained from wild mountain gorilla feces. Both the protocol itself and the descriptive results are applicable to a wide variety of research questions and projects.

  • Teaching


    Introduction to Human Evolution

    Department of Anthropology, UCLA

    Guest lectures

    Sex differences and convergences in socioendocrine mediation of life history strategies

    Department of Comparative Human Development, University of Chicago

    The biological origins of xenophobia

    Department of Anthropology, Northwestern University

    The evolutionary origins of friendship and family bonds in primates

    Department of Anthropology, Northwestern University

    Behavior and physiology research methods in wild and captive animal populations

    Department of Psychology, DePaul University

    Intersections of science and conservation policy

    Department of Psychology, DePaul University

    Darwinian medicine: senescence and genetic disease

    Department of Comparative Human Development, University of Chicago

    Kinship, culture, and the puzzle of human ultrasociality

    Department of Comparative Human Development, University of Chicago

    The behavior and physiology of male parenting: mountain gorillas, marmosets, and stay-at-home dads

    Department of Psychiatry and Behavioral Neuroscience, University of Chicago

    Paternal care in hominids

    Department of Anthropology, Santa Monica College

    Course Reader

    Evolution & Human Sexuality

    Human Behavioral Ecology

    Models of Cultural Evolution

    Primate Behavior Non-Human to Human

    Survey of Biological Evolution

    Great Adaptations: Origins of Complexity in Nature

    Department of Anthropology, UCLA

  • Affiliations

    Past and present

  • Science communication

    The Planetary Laboratory

    Current K-12 science teaching practices often limit kids' science exposure to out-of-date materials with little obvious relevance to the world children see around them. I am part of The Planetary Laboratory team, which is working to transport science from field sites, laboratories, and universities, into the classroom. Our NSF-supported project is helping teachers and kids learn how scientists solve problems, and helping scientists reach--and learn from--teachers and kids.

    General interest writing

  • Contact me