Targeted interventions can raise a nation’s average intelligence level

Evidence

In fact, this IQ increase is a variant of the “Flynn effect,” named for James R. Flynn, whose 2012 book, Are We Getting Smarter? Rising IQ in the Twenty-First Century, documented an average IQ rise of three points per decade between 1932 and 1978 in the United States and some other Western nations. Subsequent analyses have confirmed this, such as a 2014 meta-analysis in the Psychological Bulletin, which calculated the same IQ gains between 1972 and 2006.15 This suggests that the scores reflect not innate intelligence but acquired skills. — Harriet A. Washington, A Terrible Thing to Waste, 124 (#corroborates, via linked claim)

Categorization

• corroborated: 2 independent passages support this claim
• XREF: connects to: Intelligence develops from environment and experience rather than genetic inheritance; Rapid IQ gains from reduced disease burden rule out genetic explanations — Harriet A. Washington, A Terrible Thing to Waste, 945; Adding iodine to salt in 1924 raised average U.S. IQ scores — Did iodized salt raise the IQ of 50 million Americans by 15 points? (+11 more)

Related

• Population IQ scores have risen rapidly over decades, refuting fixed-IQ claims (similarity 0.90)
• Policies and interventions can raise a nation’s average IQ (similarity 0.89)
• 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 0.84)
• Disease-reduction interventions like vaccination and clean water could raise national IQ scores (similarity 0.84)
• Rapid IQ gains from reduced disease burden rule out genetic explanations (similarity 0.83)
• The generational rise in IQ scores is attributed to environmental factors like improved nutrition, education, and reduced toxin exposure. (similarity 0.83)
• Iodized salt raised IQs by a full standard deviation (15 points) in iodine-deficient areas, and may explain a decade’s worth of the Flynn effect. (similarity 0.83)
• Adding iodine to salt in 1924 raised average U.S. IQ scores (similarity 0.83)
• National infectious disease burden strongly predicts average national IQ (similarity 0.81)
• For the quarter of the population most deficient in iodine, salt iodization raised IQ by approximately one standard deviation, explaining roughly a decade’s worth of the Flynn Effect. (similarity 0.80)
• A 2013 study found a gradual increase in average intelligence of 1 standard deviation, 15 points in iodine-deficient areas and 3.5 points nationally after the introduction of iodised salt. (similarity 0.80)
• 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 0.80)
• We find that for the one quarter of the population most deficient in iodine this intervention raised IQ by approximately one standard deviation. (similarity 0.80)
• Intelligence quotient significantly influences important life outcomes (similarity 0.80)
• A 2017 study found that the introduction of iodized salt in 1924 raised IQ for the one-quarter of the population most deficient in iodine. (similarity 0.80)

Library Connections

• Population IQ scores have risen rapidly over decades, refuting fixed-IQ claims #corroborates (0.80) — Harriet A. Washington, A Terrible Thing to Waste, 124
• Iodine deficiency is a major unrecognized cause of lowered intelligence #expands (0.80) — Harriet A. Washington, A Terrible Thing to Waste, 21