Friday, June 30, 2006

Lynn Review   posted by Jason Malloy @ 6/30/2006 11:48:00 AM

As of this morning the journal Intelligence has a positive review of Lynn's Race Differences in Intelligence, from behavior geneticist John Loehlin. One issue raised earlier was the reliability of the numbers Lynn reports. Loehlin writes:

Are the numbers accurate? I checked a sample of 40 of the 615 rows in the IQ tables against their sources. . . Result: 14 of the 40, about 1 in 3, showed discrepancies, although mostly minor ones. For example, there were 9 with discrepancies in Ns, such as using an overall N from the study instead of the actual N on which the particular IQ was based. In a similar number of cases, the ages or age ranges were a bit off. . . my [IQ score] estimates and the values in the tables were typically within a couple of IQ points. I only came across one large discrepancy - an IQ 14 points too high (in Table 12.1, row 20; due, according to an e-mail from Lynn, to a clerical error in adding instead of subtracting a Flynn correction). The citations and references were, on the whole, accurate. In short: Yes, the general trends in the tables are probably dependable, if the assumptions regarding Flynn effects, etc., are correct, but it is prudent (as always) to check with original sources before quoting particular results.

Loehlin concludes in a manner similar to my review:

Is this book the final word on race differences in intelligence? Of course not. But Richard Lynn is a major player, and it is good to have his extensive work on this topic together in one place. Future workers who address these matters under this or any other label will find that Lynn has done a lot of spadework for them. And they will also find that there is plenty to ponder over within these pages.