z39\doc\web\2000\02\rushflyn.txt From: "J. P. Rushton" Here's some data I published in an exchange with Jim Flynn in the 1999 issue of Personality and Individual Differences, which is also forthcoming in the American Psychologist in a month or two. At first glance, the Flynn Effect may present itself as a way of explaining away the 1 standard deviation difference in the mean IQ of Blacks and Whites in the U.S. Yet some recent data (Table 1) does not bear this out. Table 1 shows the results of a principal components analysis of the secular gains in IQ from the U.S., Germany, Austria, and Scotland, Black-White IQ difference scores from the U.S., inbreeding depression scores from cousin marriages in Japan, and g-loadings from the WISC-R and the WISC-III standardization samples. The important findings are: (1) the IQ gains on the WISC-R and WISC-III form a cluster, showing that the secular trend is a reliable pheonomenon; but (2) that this cluster is independent of the cluster formed by Black-White differences, inbreeding depression scores (a purely genetic effect), and g-factor loadings (a largely genetic effect). This analysis shows that the secular increase in IQ and the mean Black-White IQ difference behave in entirely different ways. The secular increase is unrelated to g and other heritable measures, while the magnitude of the Black-White difference is related to heritable g and inbreeding depression. Although the Flynn Effect does suggest that improving the environment can improve test scores, and this is important to know, the cluster analysis of that effect shows that it is unrelated to the g-factor. g is associated with inbreeding depression, for which there is no non-genetic explanation, and so is less amenable to environmental manipulation. Indeed, massive evidence indicates that g is related to the size and functioning of the brain on which there are also population differences (see Jensen's, 1998 The g factor; Rushton, 1997 Race, Evolution, and Behavior). The good news is that we now know that we can do our best to improve conditions and test scores without having to deny the ever-growing evidence for the heritability of cognitive ability. Meanwhile, the secular rise in IQ remains one of the unsolved psychometric mysteries. ------------------------------------------------------------------------How to contribute to H-Bd: 1. To reply privately to just the sender of this message, click the "Reply" button on your email package. 2. To reply publicly to the entire H-Bd list, click the "Reply All" (or equivalent) button o n your email package. 3. To start a thread, email your message to h-bd@egroups.com ------------------------------------------------------------------------ GET A NEXTCARD VISA, in 30 seconds! Get rates as low as 2.9% Intro or 9.9% Fixed APR and no hidden fees. Apply NOW! http://click.egroups.com/1/915/5/_/64659/_/951272559/ -- Create a poll/survey for your group! -- http://www.egroups.com/vote?listname=h-bd&m=1