Twin Study Shows IQ 75% Heritable, Genes Drive Success
Get the Health newsletter
Daily health & science — research, biotech, public health, the studies worth knowing. Free.
- German TwinLife project followed 880 twins—half identical, half fraternal—raised in the same households to isolate genetic from environmental effects.
- IQ measured at age 23 was estimated to be 75% heritable in the sample.
- Genetic contribution accounted for 69%–98% of the association between IQ and socioeconomic outcomes (education, occupation, income) at age 27.
- Petri Kajonius and his team published the findings in Scientific Reports, stating that genetics drive much of adult success.
- Silver spoon notion was questioned, with the study suggesting that family background plays a smaller role than inherited traits.
Why it matters: Policymakers and educators must reckon with the finding that genetics explain up to 98% of the IQ‑SES link, meaning that interventions aimed at equalizing outcomes may have limited impact and could shift funding toward early‑development programs.
Ask SkimNews
