HBD: Human Biodiversity

IQ Gap Is Not Shrinking


In a paper in Intelligence, Rushton and Jensen take issue with those who think that the black/white IQ gap is narrowing, and thus may eventually disappear.

(Rushton & Jensen, 2005) and (Rushton & Jensen, 2010) maintain that the IQ gap between Blacks and Whites has remained at least 15- to 20-points (1.1 standard deviations) since the time of World War I (1917) when mass testing first began ([Roth et al., 2001] and [Shuey, 1966]). On the other hand, (Flynn, 1987b) and (Flynn, 1999b) argued that the mean difference has decreased from the Army Alpha of World War I (1917), to the Army General Classification Test of World War II (1946), to the Armed Forces Qualification Test of the Vietnam era (1968). More recently, Dickens and Flynn (2006) claimed that Blacks had closed the IQ gap by 5.5 points (35%) between 1970 and 1992. Over the same time period, Nisbett (2009) claimed that Blacks had narrowed the gap in educational achievement by a commensurate 35% on the National Assessment of Educational Progress (NAEP) tests. Nisbett also argued that educational interventions such as the Milwaukee project, the Abecedarian project, and the Infant Health and Development Program implied that the gap could be eliminated altogether.

To the contrary, we find there is little or no evidence of narrowing. The evidence presented in its favor rests mainly on insufficient sampling and selective reporting. For example, Rushton and Jensen (2006) calculated that the mean Black gain on the IQ tests discussed by Dickens and Flynn (2006) was only 2.1 points (14%) because these authors, for a variety of proffered methodological reasons, had excluded several tests showing small, nil, and negative gains, and also because they had used a projected trend line that exaggerated the gain. Nor was there any evidence of narrowing on other IQ tests over the 1970 to 1992 time period ([Murray, 2006] and [Murray, 2007]).

Nisbett's (2009) claim of a 35% Black improvement on the NAEP tests is also greatly exaggerated. Gottfredson (2005) estimated these gains were only about 20% and had ceased completely by 1990. In fact, her appraisal, as well as one by Herrnstein and Murray (1994) of a 20% Black gain may have been over-optimistic (Herrnstein and Murray, 1994, actually reported the results were mixed, with other tests showing an increasing distance between Blacks and Whites).

As the authors point out, just because IQ scores have been increasing (the Flynn Effect) over the previous several decades doesn’t give us any reason for assuming that blacks will catch up to whites, any more than the population increase in height should convince us that the male/female gap in that area will close.

I’ve always thought the real black-white gap would actually be larger if the money spent educating children was distributed by the tax contribution of parents (or if only private schools existed).  The Cato Institute reports that nationwide the US spends $19,000 per student with largely black cities like Chicago, Washington D.C., and New York City being some of the biggest spenders.  I wouldn’t be surprised if the US actually "invested" more per student on blacks than whites.  I’d like to see some numbers on tax burden by race vs. allocation per pupil.

And none of this considers the millions of blacks being born into better material circumstances than they would otherwise have thanks to affirmative action and government jobs.  Redistributionist policies should explain part of the reason why the average African American IQ is 15 points higher than that of their cousins in Africa.

As money becomes tighter and our increasing diversity makes whites more and more hostile to government spending, the next few decades should see an increase in racial disparities.