Mind the Gap

Is the white-black IQ gap shrinking in the United States?

Although many assume that the existence of sizable disparities in average IQ among the races simply must be “pseudoscience,” that different ethnicities average different levels of mental ability is one of the most overwhelmingly well-established findings of the social sciences.

Exactly why ancestral groups have varying IQs remains controversial, but the fact that they do is not disputed among the well-informed. A general rule of thumb among researchers has long been that whites and blacks differ in average IQ by about one standard deviation.

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It’s natural to be interested in whether the white-black gap has been narrowing over the generations. If the cause of the IQ gap is racism, then the obvious huge decline in racism over recent generations should have boosted black IQ scores relative to whites. Has it?

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Are black IQs going up relative to white IQs?

Perhaps slightly, due to elite immigration from Africa and increased numbers of part-black children with one white parent. For example, Barack Obama, who is a reasonably smart guy, is both the child of an African elite and of a white.

But the traditional gap between whites and descendants of American slaves with no recent white ancestry (for instance, Michelle Obama) appears to be about as large as ever in a lavish National Institutes of Health study of over 10,000 American children called Adolescent Brain Cognitive Development (or ABCD) that recruited and extensively tested a nationally representative sample of 9- and 10-year-olds in 2016–2018.

This is a gold-standard project intended to be the biggest and best study of the teenage brain. The NIH recently ponied up an additional $290 million for the second seven years of the ABCD. {snip}

Because the taxpayers are shelling out for the ABCD, it was intended to be operated on the “open science” model with the data broadly available. But that freedom is being squeezed because some scientists have lately used these huge new longitudinal databases to look into key questions of the age and found politically unwelcome answers. For example, tenured Cleveland State professor Bryan J. Pesta recently was fired after publishing a paper using the Philadelphia Neurodevelopment Cohort to examine the impact of racial admixture on IQ.

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At the Human Varieties blog last week, “Chuck” posted a summary of cognition scores from the ABCD by ethnicity.

He set the average score of children identified by their parents as non-Hispanic whites (and nothing else) to 100.0, with a standard deviation of 15.

On this metric, the 437 Asians and part-Asians averaged 105.1, which would be the 63rd percentile for whites. The 59 pure-blooded (non-hapa) northeast Asians (Chinese, Koreans, and Japanese) scored a spectacular 111.2 (77th percentile among whites), although that sample size is only modestly confidence-inducing.

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The 2,096 Hispanics had a mean IQ of 91.7, or the 29th percentile of the white distribution.

The 1,926 blacks scored 85.2, or the 16th percentile for whites: a 0.99 standard deviation gap.

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In reality, the main public-spirited step we can take regarding racial gaps in intelligence is to Raise Awareness: Racial intelligence differences are real, large, crucial for understanding American society, and not going away anytime soon. It’s something we have to live with. Just as the foot-speed gap doesn’t justify witch-hunting football coaches for being racist against white cornerbacks, the manifold effects of the intelligence gap don’t justify the current paranoid conspiracy theorizing about white racism.

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