Jordan Peterson on psychology: what the evidence says · JRE #1769
SUBJECT: PSYCHOLOGY
Not a true/false call. Every claim is logged with its sources; read the exhibits below.
the most reliable difference that psychologists have ever found between men and women, the biggest difference, is interest. So women are reliably more interested in people and men are reliably more interested in things.
What the evidence says 01 / RECORD
The claim refers to the Things-People dimension studied in Su, Rounds and Armstrong's 2009 meta-analysis of 503,188 respondents across 47 interest inventories, which found men prefer working with things and women prefer working with people, at a large effect size (d = 0.93). This is among the largest sex differences documented in psychology and has been replicated in follow-up work linking it to gender disparities across STEM fields. However, the claim that it is definitively "the biggest difference psychologists have ever found" overstates certainty: broader reviews of sex-difference research (e.g., Hyde's gender similarities hypothesis) note most psychological sex differences are small to moderate and stress methodological caveats in ranking them, while at least one competing line of research (Del Giudice et al., 2012) reports even larger multivariate sex differences in personality profiles (global effect size D = 2.71) using aggregated latent-variable methods not directly comparable to the single-dimension d = 0.93 figure. The people-things interest gap is well-supported as one of the largest and most robust single-dimension sex differences measured, but singling it out as the single largest difference ever found is a stronger and more absolute claim than the research literature, taken as a whole, supports.