Amplification explains heritability rise

Across infancy to adolescence, new genetic effects ('innovation') appear early but rapidly fall away, whereas early genetic differences are amplified over time and account for most of the rising heritability after about age eight. A meta‑analysis of longitudinal twin/adoption data (11,500 pairs) quantifies this shift and locates the developmental inflection. — If early genetic variation is amplified rather than continuously invented, policy for education and intervention must focus on early environments and how they interact with initial differences instead of assuming later interventions alone will equalize outcomes.