Comment

Contents ture and nurture of human . At standardization samples. The important find- first glance, the Flynn effect may also present ings are (a) the IQ gains on the WISC-R and Rushton on Flynn ...... 542 itself as a way of explaining away the one WISC-II1 form a cluster, showing that the Flynn replies ...... 543 difl~rence in the mean IQ secular trend is a reliable pheonomenon, but of Blacks and Whites in the United States. It (b) this cluster is independent of the cluster is unfortunate, then, that Flynn does not re- formed by Black-White differences, inbreed- port in sufficient detail a summary of what DOI: l 0.1037//0003-066X. 55.5.542 ing depression scores (a purely genetic ef- the gains over time do ~md do not tell us about fect), and g-factor loadings (a largely genetic Flynn Effects Not the nature of the Black-White difference. effect). This analysis shows that the secular Genetic and Unrelated Table 1 (taken from Rushton, 1999) increase in IQ and the mean Black-White 1Q to Race Differences shows the results of a principal components difference behave in entirely different ways. analysis of the secular gains in IQ of people The secular increase is unrelated to g and from the United States, Germany, Austria, J. Philippe Rushton other heritable measures, while the magni- and Scotland; Black White 1Q difference Universi~ of Western Ontario tude of the Black-White difference is related scores from the United States; inbreeding to heritable g and inbreeding depression. These Flynn's (January 1999) demonstration that depression scores from cousin marriages in results provide further evidence for the cru- the populations of several countries have in- Japan; and g loadings from the Wechsler cial role played by g. In his latest book, The g creased in average IQ by about three points a Intelligence Scale for Children-Revised Factor, Jensen (1998, Chapter 11) analyzed decade over the past 50 years is an important (WISC-R) and the Wechsler Intelligence Scale 17 independent data sets from 171 psycho- contribution to the of the na- for Children-Third Edition (W1SC-II1) metric tests on a total of nearly 45,000 Blacks and 245,000 Whites and found that g loadings consistently predict the magni- tude of the Black-White difference (r = +.63). Table 1 Principal Components Analysis and Varimax Rotation for Pearson Flynn's (1999, p. 5) statement that the Correlations of Inbreedinq Depression Scores, Black-White Differences, "massive IQ gains over time" provide sup- g Loadings, and Gains (~ver Time on the Wechsler Intelligence Scales for port for an environmental origin of race dif- Children (With Reliability Partialled Out) ferences is not supported by factor analysis. Although the Flynn effect does suggest that Principal component improving the environment can improve test Unrotated Varimax scores, which is important to know, the clus- loading rotated loading ter analysis of that effect shows that it is Variable I II 1 2 unrelated to the . The g factor is Inbreeding depression scores from Japan .31 .61 .26 .63 associated with inbreeding depression, for Black-White differences from the United States .29 .70 .23 .72 which there is no nongenetic explanation, WISC-R g Ioadings from the United States -.33 .90 -.40 .87 and so is less amenable to environmental WISC-III g Ioadings from the United States -.61 .64 -.66 .59 manipulation. Indeed, massive evidence indi- United States gains 1 (WISC to WISC-R) .73 -.20 .75 -.t3 cates that g is related to the size and function- United States gains 2 (WISC-R to WtSC-III) .81 .40 .77 .47 ing of the brain on which there are also Black- Germany gains .91 .03 .91 .11 White differences (Jensen, 1998; Rushton, Austria gains .87 .00 °86 .07 1997). The good news is that psychologists Scotland gains .97 .08 ,96 .17 now have the to do their best to % of total variance explained 48.60 25.49 48.44 25.65 improve conditions and test scores without Note. Data are from "Secular Gains in IQ Not Related to the g Factor and Inbreeding Depression-- denying the ever-growing evidence for the Unlike Black-White Differences: A Reply to Flynn," by J. Philippe Rushton, 1999, Personality and ndiv dual D fferences, 26, p. 387. Copyright 1999 by Elsevier Science. Reprinted with permission. of cognitive ability. Meanwhile, WISC-R = Wechsler IntelligenceScales for Children-Revised"WISC-III = Wechsler Inte genceScales for the secular rise in IQ remains one of the Children-ThirdEdition. Bold numbersindicate significant Ioadings on Factors. unsolved psychometric mysteries.

542 May 2000 • American Psychologist ( opyright 2001) by the American Psychological Association, Inc. 0003-066X/00/$5.00 Vol, 55, No, 5, 542 543 DOI: 10. I037//0003-066X.55.5.542 REFERENCES REFERENCES DOI: 10.1037//0003-066X.55.5.543 Colom, R., Juan-Espinosa, M., & Garcia, L. F. Flynn, J. R. (1999). Searching for justice: The IQ Gains and Fluid g (1999). The secular increase in test scores is discovery of IQ gains over time. American a "Jensen effect. " Manuscript submitted Psychologist, 54, 5-20. tbr publication. James R. Flynn Flynn, J. R. (1999). Searching for justice: The Jensen, A. R. (1998). The g Jactor. Westport, UniversiO' of Otago discovery of IQ gains over time. American CT: Praeger. P~2vchologist, 54, 5-20. Rushton, J. P. (1997). Race, evolution, and Rushton's (2000, this issue) point is an- Flynn, J. R. (in press). IQ gains, WISC subtests, behavior. New Brunswick, N J: Transaction. ticipated on page 16 of my article (Flynn, and fluid g: Evidence vs. g theory and the relevance of Spearman's hypothesis to race. Rushton, J. P. (1999). Secular gains in IQ not 1999). When IQ tests are ranked by fluid In Proceedings af Novartis Foundation Sym- related to the g factor and inbreeding de- g loading, there is a positive correlation posium 233: The nature of intelligence. pression-unlike Black-White differences: with the magnitude of IQ gains: The latest London: Wiley. A reply to Flynn. Personality and Indi- data show r values of .50 to .78 (Colom, Rushton, J. P. (2000). Flynn effects not ge- vidual Differences, 26, 381 389. Juan-Espinosa, & Garcia, 1999; Flynn, in netic and unrelated to race differences. press). Factor analysis then shows in- American Psychologist, 55, 542. breeding depression isolated from a clus- Correspondence concerning this comment ter including fluid g, IQ gains, and Black- Correspondence concerning this article should be should be addressed to J. Philippe Rushton, White differences (Flynn, in press). I have Department of Psychology, University of addressed to James R. Flynn, Department of Politi- Western Ontario, London, Ontario, N6A 5C2, no faith in the methodology, but such as it cal Science, University of Otago, P.O. Box 56, Canada. Electronic mail may be sent to is, it does not isolate IQ gains from Black- Dunedin, New Zealand. Electronic mail may be [email protected]. White differences. sent to [email protected].

May 2000 ° American Psychologist 543