The Cool Water Phenomenon: On the Origins of Global Psychological Variation

Abstract

Evidently, Western people differ from other cultures by exhibiting an unusually individualistic orientation and a distinctly impersonal form of prosociality. But our understanding of the origins of this “weird” Western psychology remains deficient. Recent work claims that the Western Church’s Medieval ban on cousin marriage encultured individualism and impersonal prosociality. We challenge this proposition and demonstrate instead that different ecological pressures predict psychological variation. Specifically, the Cool Water climate under which Western civilization — and especially its Protestant branch — evolved bestowed existential autonomies on nuclear families, which then nurtured individualism and impersonal prosociality. To conclude, the marriage norms of the Western Church were embraced by communities that have already evolved an individualistic and impersonally prosocial psychology for ecological reasons.