Are adoption gains on the g factor? A meta-analysis

• Adopted children generally show IQ gains.
• The correlation between subtest g loadings and adoption gains is examined.
• A psychometric meta-analysis was carried out.
• g loadings and adoption gains yield a correlation of −1.

When children are adopted into prosperous families they generally show IQ gains. The meta-analytic correlation between subtest g loadings and adoption gains is examined (K = 4, combined N = 3018). A number of meta-analytic corrections are applied to the estimate, yielding a correlation of −1. The results are discussed.