The Flynn effect (or the Lynn-Flynn effect) refers to the (earlier) observed worldwide increases in average IQ test results.
Since the start of IQ testing, raw scores on IQ tests earlier increased worldwide. For example, raw test scores on a popular IQ test in the United States increased by 3 IQ point each decade. The effect was not initially noticed, since the average score is always set to 100, when a new test IQ or a new edition of a test IQ is created and a new standardization group is tested. It only became apparent when different standardization groups were compared.
The effect was first demonstrated by Richard Lynn, when he demonstrated that the average IQ of Japan had increased substantially over several decades. A similar increase was later demonstrated in several other countries by James R. Flynn and was named the Flynn effect. It has been argued that the effect should be called the "Lynn-Flynn effect", since it was first discovered by Lynn.
See Race and intelligence: The genetics or not debate: The Flynn effect regarding possible causes, relation to the g factor, and argued implications for racial IQ differences.
See Dysgenics: Intelligence regarding the effect having (earlier) masked an opposite slower decline in genotypic IQ, due to dysgenics,, as well as recent research finding that the Flynn effect has more recently reversed in many developed countries, where IQ test results are now instead declining.
- Neisser U (1997). "Rising Scores on Intelligence Tests". American Scientist 85: 440–7. https://www.americanscientist.org/issues/feature/rising-scores-on-intelligence-tests/1
- Neisser et al. (February, 1996). Intelligence: Knowns and Unknowns. Board of Scientific Affairs of the American Psychological Association.
- Secular gains in IQ not related to the g factor and inbreeding depression -- unlike Black-White differences: A reply to Flynn. Rushton J.P. Personality and Individual Differences, Volume 26, Number 2, February 1999 , pp. 381-389(9) http://www.ingentaconnect.com/content/els/01918869/1999/00000026/00000002/art00148