F J Flynn
Flynn effect
From Wikipedia, the free encyclopedia Jump to: navigation, searchThe Flynn effect is the increase in raw scores on IQ tests over time, also called secular change in IQ. When new norms are calculated for an IQ test, it is observed that the number of correct item content scores achieved by test-takers in the norming sample typically rise compared to test-takers in previous norming samples. Similar improvements have been reported for other cognitions such as semantic and episodic memory. The effect has been observed in most parts of the world at different rates. Because IQ 100 is defined as the median score of the norming sample, current test-takers taking tests with older norms tend to have inflated scores. The Flynn effect is named for James R. Flynn, who did much to document it and promote awareness of its implications. The term itself was coined by the authors of The Bell Curve . The effect's increase has been continuous and approximately linear from the earliest years of testing to the present. There are numerous proposed explanations of the Flynn effect and also some skepticism about its implications. The Flynn effect may have ended in a few developed nations after the mid 1990s, making it possible for other countries, which still have rising scores, to catch up with those countries.
The rise
IQ tests are re-normalized periodically, in order to maintain an average score at 100. In fact, the necessity of this re-normalization provided an early indication that IQ-scores on the test were changing over time. The revised versions are standardized on new samples and scored with respect to those samples alone, so the only way to compare the difficulty of two versions of a test is to conduct a separate study in which the same subjects take both versions. Doing so confirms IQ gains over time.
The average rate of increase seems to be about three IQ points per decade. Because children attend school longer now and have become much more familiar with the testing of school-related material, one might expect the greatest gains to occur on such school content-related tests as vocabulary, arithmetic or general information. Just the opposite is the case: abilities such as these have experienced relatively small gains and even occasional decreases over the years. The greatest Flynn effects occur instead for general intelligence factor loaded (g-loaded) tests such as Raven's Progressive Matrices. For example, Dutch conscripts gained 21 points during only 30 years, or 7 points per decade, between 1952 and 1982.
Some studies emphasizing the distribution of scores have found the Flynn effect to be primarily a phenomenon of the lower end o
