Heritability of IQ rises with age

Updated: 2026.01.05 24D ago 5 sources
A meta-analysis of 11,500 twin/sibling pairs shows genetic factors explain more variance in cognitive ability as children grow. Novel genetic influences dominate very early, but after about age 8 the same genetic effects get amplified, driving increasing heritability into adolescence. — This clarifies why nature–nurture estimates shift over childhood and cautions against reading early low heritability as proof that environment alone explains cognitive outcomes.

Sources

The new genetics of intelligence - PMC
2026.01.05 82% relevant
The article summarizes developmental genetic findings showing increasing genetic influence on intelligence across childhood into adulthood, corresponding to the existing idea that heritability of cognitive ability amplifies with age.
12 Things Everyone Should Know About IQ
2026.01.04 95% relevant
The article explicitly states the core claim that IQ heritability increases from childhood to adulthood while shared‑family environmental effects fade — exactly the empirical result captured by this existing idea.
Explaining the Increasing Heritability of Cognitive Ability Across Development: A Meta-Analysis of Longitudinal Twin and Adoption Studies - PMC
2025.10.07 100% relevant
Briley & Tucker-Drob (Psychological Science, 2013) analyzed longitudinal twin/adoption data from 16 studies spanning 6 months to 18 years.
Genetic variation, brain, and intelligence differences | Molecular Psychiatry
2021.02.02 78% relevant
Deary et al. summarise longitudinal findings about stability and changing heritability across development and relate them to imaging/genetic mechanisms, supporting and contextualizing the established claim that genetic influence on measured cognition tends to increase with age.
Is Intelligence Hereditary? | Scientific American
2016.05.01 92% relevant
The article explicitly reports the same empirical claim as the existing idea: genetic influence on measured intelligence increases across development (≈20% in infancy, ≈40% in childhood, ≈60% in adulthood). It cites twin/adoption/DNA study convergence—the same empirical phenomenon the existing idea highlights.
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