Sir Cyril Burt in Perspective - Abstract - American Psychological ...

Sir Cyril Burt in PerspectiveARTHUR R. JENSENUniversity of California, BerkeleyABSTRACT: Numerical peculiarities in Sir Cyril Burt'sreports of kinship correlations are most reasonably attributableto carelessness rather than fraud. Showingstatistically significant deviations from randomness inthe final digits of correlations, Ns, and IQs, or othernonrandomness suggesting "digital preferences," is unconvincingas purported evidence that Burt's figureswere faked. -No analysis is given showing that Burt'sresults are biased so as to favor his theory, and theyare in close agreement with numerous independentstudies. Scientifically, in any case, the validity of Burt'stheory of the polygenic inheritance of intelligence doesnot depend upon Burt's data.An indefatigable veteran of controversy throughoutmost of his long and eminent career, the late SirCyril Burt continues to provoke still new disputesmore than 6 years after his death.In the fall of 1976, sensational stories appearedin London newspapers under such banner headlinesas "Crucial Data Was Faked by Eminent Psychologist"(Gillie, 1976) and "Theories of IQPioneer 'Completely Discredited'" (Devlin, 1976).In these and other articles, five psychologists(Michael McAskie, Alan and Ann Clarke, LeonKamin, and Jack Tizard) are quoted as claimingthat Burt's data on the inheritance of mental abilityare fraudulent. Yet no real substantiation of theaccusations accompanied these claims, either in theoriginal articles or in the several letters to theLondon Times by McAskie and the Clarkes (November13, 1976), Kamin (November IS, 1976),and Tizard (October 26, 1976) elaborating on theirconjectures of fraud in Burt's data on IQ heritability.Now, over a year later, McAskie (1978) servesup the first bit of seemingly intrinsic evidence forthe indictment of Burt that supposedly amountsto more than what was admittedly just "claims andstrong suspicions," and we are also promised futureevidence "currently in preparation." The presentmethod concocted by McAskie to detect fraud inBurt's figures was never even so much as hinted atin the newspaper articles, nor in the McAskie andClarkes' letter to the Times, nor in my more recentpersonal correspondence with McAskie's colleague,Ann Clarke (Note 1), concerning the basisof the charges against Burt.May I suggest that we try to gain a proper perspectiveon the Burt affair.At least a substantial first step in this directionwas made in my 1974 article, which examinedBurt's published kinship correlations that were thebasis of his famous studies of the heritability of intelligence(Jensen, 1974). My original intention,in writing that article, was systematically to assemble,for the convenience of students of behavioralgenetics, all the empirical results from Burt'smany kinship studies that were scattered in variousjournals published from 1943 to 1972. Many ofBurt's reports are cumulative, in the sense of enlargingsample sizes for certain kinship correlationsand carrying over into later articles and reanalysesof IQ heritability some of the same correlations hehad reported in previous papers. Also, some of thesame errors in earlier articles get repeated identicallyone or more times in Burt's later articles. Inthe year-to-year cross-tabulations of all of thismaterial in the nine large tables in my review, anumber of peculiarities in some of the repeatedcorrelations (rs) and their sample sizes (Ns) becameclearly evident. It seemed they must beerroneous, or at least certainly puzzling, and Iclearly pointed this out, with the caveat that thesequestionable correlations must therefore be deemeduseless for hypothesis testing involving geneticmodels of IQ variation.What these errors, or at least peculiarities, incertain rs and their Ns consist of can be easily summarized.Burt reported, altogether, 235 kinshipcorrelations of various types (twins, siblings, parent-child,cousins, etc.), on three classes of variables:intelligence, scholastic achievement, andphysical measurements. The sample size (N) isRequests for reprints should ,be sent to Arthur R. Jensen,Institute of Human Learning, University of California,Berkeley, California 94720.AMERICAN PSYCHOLOGIST • MAY 1978 • 499Copyright 1978 by the American Psychological Association, Inc.0003-066X/78/3305-0499$00.75

A ATC/^^DV000 010 0,20 030 MO 030OjSO 070 Q80 090GROUPSINCLUDEDUNRELATEDPERSONS45FOSTERRARENT-3PARENT- CHILDSIBLINGSTW1NSTWO-EGGONE- EGGREARED APART • ^rREARED APARTREARED TOGETHER4k/ V^ ^^t122359II414Figure 1. Correlation coefficients for "intelligence" test scores from 52 studies. Somestudies reported data for more than one relationship category; some included more than onesample per category, giving a total of 99 groups. Over two-thirds of the correlation coefficientswere derived from IQs, the remainder from special tests (for example, PrimaryMental Abilities). The midparent-child correlation was used when available; otherwise,the mother-child correlation. Correlation coefficients obtained in each study are indicatedby dark circles; medians are shown by vertical lines intersecting the horizontal lines whichrepresent the ranges. (From "Hurt's IQ Data," letter by B. Rimland and H. Munsinger,Science, 1977, 195 (January 12, 1977), 248. Copyright 1977 by the American Associationfor the Advancement of Science. Reprinted by permission.)the original tables in Newman et al. This hardlylooks like fraud.Since the appearance of my 1974 article, theclaims of Burt's critics have escalated from theinitial prima facie evidence of carelessness, tocharges of bfas, and now, finally, to the worst crimea scientist can be accused of—publishing purportedlyempirical data and results that were onlymanufactured out of whole cloth to promote theirauthor's own theoretical position—in short, absolutefraud.It seems to me extremely difficult, although ofcourse never wholly impossible, to imagine that ascholar of Burt's distinction, phenomenal industry,and pioneer dedication to the development of psychologyas a quantitative, scientific discipline couldactually be guilty of such a charge. It would indeedbe disillusioning, but, after all, it is now believedthat Gregor Mendel doctored his data(Fisher, 1936) and Isaac Newton fudged his figures(Westfall, 1973) to fit their theories, so really noone can ever be regarded as entirely above suspicion.But we do know that Burt was an inveteratestatistical analyst, and he had ready access toenormous sources of test data during his 20-years'tenure as chief psychologist to the London schools.So the idea that he would have invented all thesedata on twins and various other kinship correlationsseems bizarre, to say the least. Moreover, a wellknownBritish researcher on twins, James Shields,informed me in personal correspondence, long beforethe recent charges of fraud, that in the courseof his own research he came across a number oftwins who said they had been tested by Burt.Also, Burt's biographer, Leslie Hearnshaw, the leadinghistorian of British psychology, has informedme of independent testimony of a twin who wastested by Burt's assistant, Margaret Howard.(Burt's detractors originally claimed that MissHoward was a fictitious person invented by Burtas a co-author of one his important articles, butshe has since been identified as a real person bya psychology professor at Manchester University,John Cohen, who testifies he knew Miss Howardwhile he was a PhD student under Burt [Cohen,1976].)Neither does the notion of fakery accord withthe testimony of a distinguished colleague of Burt's,AMERICAN PSYCHOLOGIST • MAY 1978 • SOI