America is weirder than WEIRD

Henrich and colleagues’ WEIRD framework has brought crucial attention to the cultural specificity of much psychological science, showing that many foundational findings are erroneously treated as universal despite being drawn from populations that are Western, Educated, Industrialized, Rich, and Democratic. However, we argue that applications of this framework largely underestimate the degree to which the United States (where much of psychological science has been developed) is not merely WEIRD, but an extreme cultural outlier even among WEIRD societies. Via a cultural evolutionary lens, we introduce the Cultural Selection Model (CSM) to describe how American culture selected for particular values, behaviors, and cognitive styles through historically unique founder effects, including Calvinist moral ideology, chattel slavery/racial binarism, and frontier individualism. As these unique selection pressures have profoundly shaped American psychology, we argue that their cultural derivatives should not be mistaken for universally WEIRD tendencies. We explore implications of the CSM for Americans’ distinct tendency to moralize market participation, compared to peer WEIRD cultures.