-The scatterplots of nationally-representative test scores are interesting. The black–white gap _did_ shrink between '70s when it was about 1.3 standard deviations, until about 1990s, but has been stubbornly stable since then at about 0.85 standard deviations. Murray estimates the current white–Latino difference at 0.62 standard deviations, and the current white–Asian difference at 0.3 standard deviations (favoring Asians).
+The next four chapters follow a formula: "Race Differences in Cognitive Ability", "Race Differences in Violent Crime", "First-Order Effects of Race Differences in Cognitive Ability", and "First-Order Effects of Race Differences in Violent Crime." (Those chapter titles felt awful just to type!! Am I really doing this?) Much of the value of these chapters is in the graphs and tables documenting statistics that many readers will be unfamiliar with. The scatterplots of nationally-representative test scores are interesting. The black–white gap _did_ shrink between '70s when it was about 1.3 standard deviations, until about the 1990s, but has been stubbornly stable since then at about 0.85 standard deviations (a.k.a. [Cohen's _d_](/2019/Sep/does-general-intelligence-deflate-standardized-effect-sizes-of-cognitive-sex-differences/)). Murray estimates the current white–Latino difference at 0.62 standard deviations, and the current white–Asian difference at 0.3 standard deviations (favoring Asians).
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+Of course, one can't just point to test scores and say "Those are the facts" without addressing what test scores _mean_. A vast space of "objective" procedures can come up with a number, without giving anyone a reason to care about that particular number. (People with more letters in their name take longer to say their name out loud, on average! Cats do better than humans on a test of scratching, on average!) In this matter of cognitive ability scores by race, Murray briefly addresses two popular (but mutually in tension) classes of objection: that the gaps will vanish with better (more equitable) education policy, and that the tests are biased.
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+The response to the we-can-fix-it objection is basically, "We tried that and it didn't work": a lot of money and effort has been poured into attempts to narrow the racial achievement gap over the past thirty years of its stability, and no known intervention seems to provide lasting gains. The response to the tests-are-biased objection is basically, "We checked for that and it doesn't work": [TODO: continue p. 42 ...]