IQ and Socioeconomic Status: TwinLife Study Finds 69-98% Genetic Overlap
A 2026 TwinLife analysis found that cognitive ability at age 23 predicted education and occupational status at age 27, and bivariate twin models attributed 69-98% of the shared IQ–SES variance to genetic factors rather than unique environment.1 The calibrated reading is narrow but important: the finding argues against treating cognition, schooling, and occupation as purely …