Minnesota Transracial Adoption Study

The Minnesota Transracial Adoption Study examined the IQ test scores of 130 black or interracial children adopted by advantaged white families. It has been a focus for controversy in the debate over race and intelligence.

The aim of the study was to determine the contribution of environmental and genetic factors to the average underperformance of black children on IQ tests as compared to white children. The initial study was published in 1976 by Sandra Scarr and Richard A. Weinberg. A follow-up study was published in 1992 by Richard Weinberg, Sandra Scarr and Irwin D. Waldman. Another related study investigating social adjustment in a subsample of the adopted black children was published in 1996. The 1992 follow-up study found that "social environment maintains a dominant role in determining the average IQ level of black and interracial children and that both social and genetic variables contribute to individual variations among them."

In 1994, researchers such as Levin and Lynn argued that these findings supported the view that genetics is a determinant of average differences in IQ text performance between races, while other researchers, including Weinberg, Scarr and Waldman, argued that the findings aligned with environmental explanations, noting that the IQ scores of the black children were slightly higher than the national average.

Subsequent developments in genetics research have led to a scholarly consensus that the hereditarian hypothesis of Levin and Lynn is false. The idea that there are genetically determined differences in intelligence between racial groups is now considered discredited by mainstream science.