Psychological research on social influence illuminates many mechanisms through which role differentiation and collaborative interdependence may affect cultural evolution. We focus here on psychological processes that produce specific patterns of asymmetric influence, which in turn can have predictable consequences for the emergence and transmission of group-level traits.

Different groups, because they are perceived to pose different threats, elicit different prejudices. Collective action by disadvantaged groups can amplify the perception of specific threats, with predictable and potentially counterproductive consequences. It is important to carefully consider the threat-based psychology of prejudice before implementing any strategy intended to promote positive social change.

Atran & Norenzayan's (A&N's) analysis fits with other perspectives on evoked culture: Cultural beliefs might emerge simply from the fact that people share a common cognitive architecture. But no perspective on culture can be complete without incorporating the unstoppable role of communication. The evolutionary landscape of culture will be most completely mapped by theories that describe specifically how communication translates evolved cognitive canals into cultural beliefs.

At least four conceptually distinct mechanisms may mediate relations between parasite-stress and cultural outcomes: genetic evolution, developmental plasticity, neurocognitive flexibility, and cultural transmission. These mechanisms may operate independently or in conjunction with one another. Rigorous research on specific mediating mechanisms is required to more completely articulate implications of parasite stress on human psychology and human culture.

Adaptationist explanations for well-known phenomena are of limited value to psychological science. To be truly useful, evolutionary psychological research programs must produce novel discoveries about contemporary cognitive and behavioral processes. The concept of special design is especially useful. Even if special design cannot be convincingly demonstrated, rigorous attempts to meet this evidentiary standard can produce novel scientific contributions.