Flynn effect

Abstract: This study shows that every Stanford-Binet and Wechsler standardization sample from 1932 to 1978 established norms of a higher standard than its predecessor. The obvious interpretation of this pattern is that representative samples of Americans did better and better on IQ tests over a period of 46 years, the total gain amounting to a rise in mean IQ of 13.8 points. The implications of this finding are developed: The combination of IQ gains and the decline in Scholastic Aptitude Test scores seems almost inexplicable; obsolete norms have acted as an unrecognized confounding variable in hundreds of studies; and IQ gains of this magnitude pose a serious problem of causal explanation.

Abstract: The purpose of this article was to examine the logic and the empirical data supporting the proposition that intelligence tests are not necessary for the definition of a learning disability. Four assumptions of the use of IQ test scores in the definition of learning disabilities were examined. These assumptions were (a) IQ tests measure intelligence; (b) intelligence and achievement are independent, and the presence of a learning disability will not affect IQ scores; (c) IQ scores predict reading, and children with low IQ scores should be poor readers; and (d) reading disabled children with different IQ scores have different cognitive processes and information skills. It was argued that IQ scores measure factual knowledge, expressive language abilities, and short-term memory, among other skills, and that because children with learning disabilities have deficits in these areas, their scores may be spuriously low. It was also shown that some children with low IQ scores can be good readers, indicating that low IQ scores do not necessarily result in poor reading. Empirical evidence was presented that poor readers at a variety of IQ levels show similar reading, spelling, language, and memory deficits. On logical and empirical grounds, IQ test scores are not necessary for the definition of learning disabilities.

Abstract: Vocabulary scores were examined in a total of 210 articles, containing 324 independent pairings of younger and older adults, from the 1986-2001 issues of Psychology and Aging. The average effect size, favoring the old, was 0.80 SD. Production tests yielded smaller effects (0.68 SD) than multiple-choice tests (0.93 SD). Both age and education were found to be partially independent determinants of performance in production tests; age effects disappeared in multiple-choice tests as soon as education was taken into account. In addition, the Wechsler Adult Intelligence Scale--Revised Vocabulary subtest (D. Wechsler, 1981) was also found to be sensitive to the Flynn effect (J. R. Flynn, 1987; i.e., increasing test scores with advancing birth year). The results question the approach of using age-group equality in vocabulary scores as a check on sample equivalence.

Abstract: Introduction - Rising Test Scores and What They mean IQ Gains Over Time - Towards Finding the Causes Environmental Complexity and the Flynn Effect The Cultural Evolution of IQ Are We Raising Smarter Kids Today? School and Home Related Influences on IQ The Role of Nutrition in the Development of Intelligence Nutrition and the Worldwide Rise in IQ Scores In Support of the Nutrition Theory Trends in Black-White Test Score Differentials - Uses and Misuses Exploring the Rapid Rise in Black Achievement Scores in the United States The Shrinking Gap Between High and Low Scoring Groups Current Trends and Possible Causes Trends in Black-White Test Score Differentials - the Wordsum Vocabulary Test The Decline of Genotypic Intelligence Problems in Inferring Dysgenic Trends for Intelligence Differential Fertility by IQ and the IQ Distribution of a Population Whither Dysgenics? Comments on Lynn and Preston.