Human social groups are central to social organization and pervasively impact interpersonal
interactions. Although immensely varied, all social groups can be considered specific …

Extensive cooperation among unrelated individuals is unique to humans, who often sacrifice
personal benefits for the common good and work together to achieve what they are unable …

From early in development, humans show a strong preference for members of their own
groups, even in so-called minimal (ie, arbitrary and unfamiliar) groups, leading to …

Affective polarization describes the phenomenon whereby people identifying as Republican
or Democrat tend to view opposing partisans negatively and co-partisans positively. Though …

People often display ingroup bias in punishment, punishing outgroup members more
harshly than ingroup members. However, the impact of group membership may be less …

Social scientists have a potentially important role to play in combatting discrimination and
hate-motivated aggression, as has been noted for over 50 years. Nonetheless, there is still …

How does cognitive sophistication impact cooperation? We explore this question using a
model of the co-evolution of cooperation and cognition. In our model, agents confront social …

Humans' willingness to bear costs to benefit others is an evolutionary puzzle. Cultural group
selection proposes a possible answer to this puzzle—cooperative norms and institutions …

Exposure to war-related violence is associated with greater prosocial behavior. Although
researchers point to empathy and individual differences in posttraumatic growth to explain …

Third-party punishment (TPP) is critical for promoting cooperation and maintaining societal
stability by deterring norm violations. Research has shown that TPP is influenced by ingroup …