Saturday, August 30, 2008

US Adult Black-White IQ Gap Now 13.2 Points Not 15 Points

The latest death toll figures from Hurricane Katrina can be seen on this website here. The famous Russian neo-Nazi video is on this blog here.

Updated September 2:

I've already gone over this before, but it's worth another post, because most folks haven't heard of it.

It appears, looking at the chart below, that IQ's have been renormed in the US. That's the only way to explain the anomalous IQ scores for both Blacks and Whites.

With the renorming, on the WAIS:

US White adult IQ = 102.6 (103)*
US Black adult IQ = 89.1 (89)*
B-W gap for age 25+ = 13.5 points.

With (my) renorming, on the AFQT:

US White IQ = 103 (103)*
US Black adult IQ = 88.6 (89)*
B-W gap for 18-23 yrs old = 14.4 points

With the renorming, on the Stanford-Binet (ages 3-23):

US White IQ 3-23 yrs = 102.9 (103)*
US Black IQ 3-23 yrs = 92.1 (92)*
B-W gap for 3-23 yrs old = 10.8 points

With the renorming, on the WAIS (ages 18-24):

US White IQ 18-24 yrs = 102.6 (103)*
US Black IQ 18-24 yrs = 90.9 (91)*
B-W gap for 18-24 yrs old = 11.7 points

With the renorming, on the WISC (ages 6-16):

US White IQ 6-16 yrs = 103.2 (103)*
US Black IQ 6-16 yrs = 91.7 (92)*
B-W gap for 6-16 yrs old = 11.5 points

Averaging the three tests for adults together, we get a B-W gap of 13.2 points, not 15 points. Averaging two tests together for young Blacks from 3-23, we get a B-W gap of 11.2 points, not 15 points.

The change was that previously IQ was normed at US White IQ = 100. It's now US population IQ = 100. So both Blacks and Whites went up.


These scores are taken from this paper, and indicate varying scores for IQ tests and semi-IQ tests taken over about 30 years. As you move down in each individual row, you move into revised versions of the tests in more recent years.

As you can see, White adult IQ (age 25+) in the US is now 102.6, or 103 rounded off. Black adult IQ (age 25+) has increased in recent years to 89.1 or 89 rounded off. There remains a 13.5 point gap between Blacks and Whites. It is no longer appropriate to say that Blacks have an IQ of 85. The B-W child gap is about 11 points. On the Stanford-Binet test, which can be given to both children and adults, there is a 10.8 point gap, but it would be nice to see who the S-B was given to, kids or adults. I suspect kids.

If you notice, even the White score on the AFQT (Armed Forces Qualifying Test) is low - it's 100, when it ought to be 103. If you read the text, the AFQT was not renormed. White IQ was set at 100 by Flynn and Dickens "by convention". They're just setting 100 as average White IQ on that test. That's equivalent to the pre-renorming IQ tests that also set 100 at US White IQ.

Post renorming, we find the Black score at 88.6 and the White score at 103. This is quite close to the 89.1 Black score for the WAIS. The gap between the US White and Black scores on the AFQT is 14.4. If we average the three together, we get a 12.9 point B-W gap


The B-W adult IQ gap is now 13 points in the US for adults on the WAIS and the AFQT.

The 15 point B-W IQ gap is gone; it's been closing a bit lately, so we ought to quit saying "15 point IQ gap".

And in kids, the B-W IQ gap on the WISC is down to 11.5 points. On the Stanford-Binet, the B-W IQ gap is down to 10.8 points. It was given to persons aged 3-23.

The new figures are being criticized because they left off some tests. But those tests are not even used very much. The WISC, the WAIS and the Stanford-Binet are the gold standards for intelligence testing. The other tests are Johnson-Woodcock, Wonderlic, Differential Ability, K-ABC.

Some of these tests are "quick and dirty" IQ tests. The Wonderlic, for example, is widely used in the NFL. I never realized they tested these apes for brains. It takes only 12 minutes. In contrast, the WAIS and the Standford-Binet can take up to 1-2 hours.

References

Dickens, William T. & Flynn, James R. October 2006. Black Americans Reduce the Racial IQ Gap: Evidence from Standardization Samples. Psychological Science.

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