Two Meanings of Low Heritability

Updated: 2025.10.07 14D ago 5 sources
Low heritability can arise because a trait is biologically rigid with almost no variance left to explain (ten fingers), or because environmental/context variation swamps genetic effects (number of children). Distinguishing these cases requires parsing family/twin h², SNP-based h², and GWAS/PGS results across cohorts. — This reframes media and policy claims that 'low heritability means not genetic' and guides how we interpret and deploy polygenic scores across populations and time.

Sources

Explaining the Increasing Heritability of Cognitive Ability Across Development: A Meta-Analysis of Longitudinal Twin and Adoption Studies - PMC
2025.10.07 50% relevant
This paper demonstrates that heritability is not fixed: it is lower in early childhood and rises with age due to amplification. That complements the warning that low heritability can reflect context and measurement—here, developmental stage—rather than a trait being 'not genetic.'
How Low You Can Go in the Third World
Steve Sailer 2025.09.28 62% relevant
By showing African‑American PISA reading scores (459) versus Zambia’s PISA‑D (275) on aligned scales and concluding 'genes aren’t everything,' the article exemplifies how environmental/context differences can swamp genetic effects in educational outcomes, echoing the caution that low heritability (or large group gaps) need not imply 'not genetic' but often reflect context.
What a New Massive Mexican Family Study Tells Us About the Effects of Ancestry on Different Traits
Davide Piffer 2025.09.11 85% relevant
The study finds near-zero heritability for educational attainment within Mexican families while height and type 2 diabetes show strong genetic ancestry effects, exemplifying how low heritability can reflect dominant environmental/context effects rather than an absence of biology.
When Low Heritability Means Different Things: Number of Children vs. Number of Fingers
Davide Piffer 2025.09.03 100% relevant
The article juxtaposes finger count vs fertility and defines h², h²_SNP, h²_GWAS, plus 'hidden heritability' from cross-population heterogeneity.
When Low Heritability Means Different Things: Number of Children vs. Number of Fingers
Davide Piffer 2025.09.03 95% relevant
The piece explicitly contrasts near‑zero heritability from trait invariance (ten fingers) with low GWAS signal for fertility despite meaningful twin/SNP heritability, and walks through h², h²_SNP, h²_GWAS, and 'hidden heritability'—exactly the framework in the existing idea.
← Back to All Ideas