The generational rise in IQ scores is attributed to environmental factors like improved nutrition, education, and reduced toxin exposure.

Evidence

The Flynn Effect – Explaining Increasing IQ Scores (SimplyPsychology)

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; Toxocara canis infection lowers IQ independent of socioeconomic and racial factors — Harriet A. Washington, A Terrible Thing to Waste, 980; Population IQ scores have risen rapidly over decades, refuting fixed-IQ claims — Harriet A. Washington, A Terrible Thing to Waste, 124 (+21 more)

Related

• 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 0.89)
• Population IQ scores have risen rapidly over decades, refuting fixed-IQ claims (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 0.85)
• Disease-reduction interventions like vaccination and clean water could raise national IQ scores (similarity 0.85)
• 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 0.83)
• Targeted interventions can raise a nation’s average intelligence level (similarity 0.83)
• Rapid IQ gains from reduced disease burden rule out genetic explanations (similarity 0.81)
• IQ predicts job performance, academic achievement, and mortality better than any known psychological factor (similarity 0.81)
• 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). (similarity 0.81)
• Intelligence is malleable and shaped by environment, not fixed by heredity (similarity 0.81)
• The secular trend in growth is almost entirely due to environmental factors since genetic changes in a whole population take far longer than the observed time interval. (similarity 0.80)
• Intelligence develops from environment and experience rather than genetic inheritance (similarity 0.80)
• Genetic causation of a trait does not imply the trait is unchangeable (similarity 0.80)
• IQ’s link to income mostly reflects environment’s link to both (similarity 0.80)
• Policies and interventions can raise a nation’s average IQ (similarity 0.79)