Postdoctoral Fellowship: SPRF: The Ecology and Evolution of Social Interdependence in Primates

This award was provided as part of the NSF Social, Behavioral and Economic Sciences Postdoctoral Research Fellowships (SPRF) program. The goal of the SPRF program is to prepare promising, early career doctoral-level scientists for scientific careers in academia, industry or private sector, and government. SPRF awards involve two years of training under the sponsorship of established scientists and encourage Postdoctoral Fellows to perform independent research.

NSF seeks to promote the participation of scientists from all segments of the scientific community, including those from underrepresented groups, in its research programs and activities; the postdoctoral period is considered to be an important level of professional development in attaining this goal. Each Postdoctoral Fellow must address important scientific questions that advance their respective disciplinary fields.

Under the sponsorship of Drs. Joan Silk and Jason Kamilar, this postdoctoral research fellowship, hosted at Arizona State University, supports an early career scientist examining how and why the social groups of closely related primate species differ in their composition and structure. While most primate groups remain cohesive, others split into small, discrete social clusters, resulting in a patchwork of neighboring family groups that subtly mirrors the shape of human communities.

This fracturing process could be triggered by ecological hardships, social threats, or some combination of ecological and social challenges. However, previous tests of these possibilities have lacked the dense, detailed behavioral data necessary to quantify subtle differences between species, instead relying on coarse, simplistic social categories. To address these gaps in our understanding, this project will combine and collate data from several multidecadal primate field projects.

Using this rich dataset, the present study will then capture social variation and its drivers both within social groups and across study populations. Using closely related primates as models for human social evolution, this project will pinpoint forces that could have pushed ancestral human groups to first form interdependent family “cliques” long before the emergence of complex, ultrasocial communities.

More broadly, the database enabled by and generated through this research will become an invaluable tool for methods development, teaching opportunities, and broader scientific use.

This project will quantify social network structure and identify its drivers in baboons and other papionin primates — a group that has long been promoted as a useful model for human evolution and has been studied intensively. However, this clade is not a monolith, inhabiting varied environments and comprising disparate social structures. Most notably, a few papionin taxa independently evolved “multi-level societies,” in which small social groups are hierarchically nested within larger supergroups.

However, the purported evolutionary causes of this flexible social system vary widely, may differ between lineages, and have yet to be rigorously tested. Combining a wealth of longitudinal data with cutting-edge analytical approaches, this project will achieve the following research aims: (1) capture the extent to which kinship, social status, and shared reproductive interests shape the strength of dyadic relationships within and across study populations; (2) track group-level changes in social network structure in response to both nutritional shortfalls and social upheavals; and (3) develop phylogenetically informed models linking cross-population network variation with key social, ecological, and demographic variables.

By combining these complementary analytical approaches, the project is well poised to target long-standing questions regarding primate social evolution and identify the broader underpinnings of variation in social structure. The project will also provide value-added to decades of field research, uniting dense behavioral datasets that have previously only been analyzed in isolation, facilitating methodological advances, and building infrastructure necessary to achieve the comparative goals that initially motivated primate research within the anthropological sciences.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.