High heritability of individual differences and large environmental effects on population-level IQ are mathematically compatible under a reciprocal gene-environment coupling model (Dickens & Flynn).

Evidence

Does the raising IQ-raising g distinction explain the fadeout effect? (ScienceDirect)

Categorization

• corroborated: 2 independent passages support this claim
• XREF: connects to: Intelligence is malleable and shaped by environment, not fixed by heredity — Harriet A. Washington, A Terrible Thing to Waste, 54; Population IQ scores have risen rapidly over decades, refuting fixed-IQ claims — Harriet A. Washington, A Terrible Thing to Waste, 124; Lewontin’s corn thought experiment shows within-group phenotypic variation can be genetic while between-group variation is environmental, since within-group heritability is irrelevant for determining causes of among-group differences. — Heritability within groups is uninformative about differences among groups: Cases from behavioral, evolutionary, and statistical genetics (+8 more)

Related

• Lewontin’s corn thought experiment shows within-group phenotypic variation can be genetic while between-group variation is environmental, since within-group heritability is irrelevant for… (similarity 0.88)
• Large positive and negative trends in cohort IQ operate within as well as across families, implying at most a minor role for genes, with environment as the main driver. (similarity 0.86)
• With heritability well below 1.00, IQ must be subject to substantial environmental influences, though genetic influence increases with age while shared family environment effects shrink by late… (similarity 0.84)
• IQ’s link to income mostly reflects environment’s link to both (similarity 0.84)
• Intelligence is malleable and shaped by environment, not fixed by heredity (similarity 0.84)
• Mixed-race children’s IQ tracks rearing environment, not racial genetics (similarity 0.84)
• Intelligence develops from environment and experience rather than genetic inheritance (similarity 0.83)
• Mixed-race IQ patterns refute claims of inherited racial intelligence differences. (similarity 0.82)
• Twin and adoption studies estimate genetic contribution to intelligence at 50–70% heritability, though molecular GWAS estimates run lower. (similarity 0.81)
• IQ has risen across generations worldwide, and the effect must be environmental since genetic mutation could not act that fast, amounting to about 15 IQ points per generation on fluid tests. (similarity 0.81)
• The generational rise in IQ scores is attributed to environmental factors like improved nutrition, education, and reduced toxin exposure. (similarity 0.81)
• Genetic factors are often responsible for variation within populations, while environmental factors are usually responsible for variation between populations, per Rose’s causes-of-cases vs… (similarity 0.81)
• With heritability well below 1.00, IQ must be subject to substantial environmental influences, though genetic influence increases with age while shared family environment effects shrink by late adolescence. (similarity 0.80)
• Genetic causation of a trait does not imply the trait is unchangeable (similarity 0.79)
• Population IQ scores have risen rapidly over decades, refuting fixed-IQ claims (similarity 0.78)

Broader Connections

• Mixed-race children’s IQ tracks rearing environment, not racial genetics #qualifies (0.60) — Harriet A. Washington, A Terrible Thing to Waste, 119