Common Ground and Differences
Abstract
Rushton and Jensen concede that the magnitude of the black/white IQ gap is not immutable but could have narrowed by as much as 3.44 IQ points or 0.23 white SDs. They concur that the black/white IQ gap rises with age. Using Shuey’s 1966 data, Jensen (1998) estimates: 0.70 SDs in early childhood; 1.00 SDs in middle childhood; 1.20 SDs in early adulthood. Our current estimates: 0.31 SDs (age 4); 0.63 SDs (age 12); and 0.87 SDs (age 18). Comparison of their pre-rise values and our post-rise values yield a black IQ gain of 0.33 to 0.39 SDs. This equals 5.0 to 5.5 IQ points, close to the mid-point of our estimate that blacks gained 4 to 7 points. Therefore, unless they question our current values, our main contention is also conceded. All that is at stake is the timing of the steps by which blacks progressed from Jensen's values to ours, something we grant to be problematic. And yet, Rushton and Jensen never challenge our values for current black IQ. They do argue that we exaggerate the qualitative difference between samples we consider suspect and samples we favor, namely, those used to standardize the WISC, WAIS, Stanford-Binet, and AFQT. They note that the latter are selected to be representative of Americans in general but not the black and white sub-populations. First, this is untrue of the sample used to
- DOI
- 10.1111/j.1467-9280.2006.01804.x
- Sources
- openalex