The Scarr–Rowe Interaction Between Measured Socioeconomic Status and the Heritability of Cognitive Ability

The hypothesis that the heritability of cognitive ability might vary with socioeconomic status (SES) was first forwarded by Sandra Scarr in a 1971 paper published in Science. Introducing a study of Black and White twins in the Philadelphia school system, Scarr wrote: “The environmental disadvantage hypothesis predicts that IQ scores within advantaged groups will show larger proportions of genetic variance and smaller proportions of environmental variance than IQ scores for disadvantaged groups” (p. 1286).