How Cultural Norms Structure the Evolution of Human Behavior and Psychology

Monday, March 4, 2024 (2 PM – 3:30 PM)

Sarah Mathew

Arizona State University

Culturally transmitted norms have likely structured the selection pressures shaping human behavior and psychology, but focused studies are needed to establish the exact pathways and outcomes of this co-evolutionary process. I present two studies which incorporate our long-standing cultural capacity to develop hypotheses of human behavior in the context of cooperation and conflict. The first study will illustrate how competition between culturally differentiated populations, i.e. cultural group selection, structures the social scale of cooperation in transient interactions with strangers. The second study shows how certain features of combat-related psychological stress can be explained as a psychological adaptation to culturally-structured normative landscapes. Data for these studies were collected in pastoral communities living in northwest Kenya.