Hormones, behavior, and social network analysis: Exploring associations between cortisol, testosterone, and network structure

• Social network analysis is used to test associations between hormones and network structure.
• Cortisol was negatively related to network activity.
• Cortisol was not associated with network popularity and homophily.
• Testosterone was not related to network structure.
• Individual differences in cortisol levels are associated with social environment.

We used a new interdisciplinary paradigm of social network analysis (SNA) to investigate associations between hormones and social network structures. We examine these biobehavioral processes and test hypotheses about how hormones are associated with social network structures using exponential random graph modeling (ERGM) in a cohort of first-year students (n = 74; 93% female; M age = 27 years) from a highly competitive, accelerated nursing program. Participants completed friendship nominations and as a group simultaneously donated saliva (later assayed for cortisol and testosterone). ERGM analyses revealed that salivary cortisol levels were inversely associated with the number of outgoing ties (i.e., network activity). By contrast, testosterone was not related to friendship network structure. Integration of SNA and salivary bioscience creates a novel approach to understanding hormone–behavior relationships within the context of human social ecologies.