August 15, 2006

The black-white IQ gap -- has it narrowed?

Over at GNXP, Darth Quixote has a good graph responding to the claim in the Flynn - Dickens paper arguing for a recent 4 to 7 point closure of the notorious 15 point white-black IQ gap. His graph shows that all the closure has been in tests of children rather than of adults, as I suggested earlier on iSteve. This leaves unanswered the question of whether adult black IQ can be expected to rise as these children go up, or does black IQ tend to fall during adulthood?

I asked them to create another plot with average birth year of the sample along the horizontal axis. The blue line tracks average scores of black children, which are now up around 89. The red line for teens, now at 87, the green line for young adults, now at 85, down a few points from earlier, and the pink adult line flat at 85.

The black-white IQ gap -- has it narrowed? Over at GNXP, Darth Quixote has a good graph responding to the claim in the Flynn - Dickens paper arguing for a recent 4 to 7 point closure of the notorious 15 point white-black IQ gap. His graph shows that all the closure has been in tests of children rather than of adults, as I suggested earlier on iSteve. This leaves unanswered the question of whether adult black IQ can be expected to rise as these children go up, or does black IQ tend to fall during adulthood?

I asked them to create another plot with average birth year of the sample along the horizontal axis. The blue line tracks average scores of black children, which are now up around 89. The red line for teens, now at 87, the green line for young adults, now at 85, down a few points from earlier, and the pink adult line flat at 85.

This seems to show that blacks born in the years roughly 1955 to 1975 saw rising IQ scores. That's not too surprising. Those were prosperous years with black life improving in many ways. I would guess that a shortage of calories for pregnant black women stopped being a problem for them. I wouldn't be surprised if average height grew quickly during those years too. Since then, the results are more ambiguous.

This seems to show that blacks born in the years roughly 1955 to 1975 saw rising IQ scores. That's not too surprising. Those were prosperous years with black life improving in many ways. I would guess that a shortage of calories for pregnant black women stopped being a problem for them. I wouldn't be surprised if average height grew quickly during those years too. Since then, the results are more ambiguous.


My published articles are archived at iSteve.com -- Steve Sailer

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