Friday, February 10, 2012

Class and Race

This recent paper (NYTimes coverage) notes that achievement gaps between 10th and 90th percentile income families are now larger than corresponding black-white gaps.

Click for larger figures. The shaded shapes indicate 10-90 gaps, whereas unshaded figures indicate B-W gaps.


Steve Sailer said...

The graphs with the actual data points on them aren't as persuasive as the nice stylized fitted curves in the NYT article. For instance, National Longitudinal Studies of Youth in 1979 and 1997, which would seem like the most apples to apples comparisons, don't show a rising correlation of parental income and achievement. . Then again, NLSY79 was already a mile above the curve, and NLSY97 merely reproduced the same size effect, with other studies catching up with it. Since "The Bell Curve" was based on NLSY79, this doesn't sound like a new trend to people who read The Bell Curve with care -- Herrnstein and Murray predicted it a long time ago. 

In summary, meta-analysis is hard.

Iamexpert said...

Scores on measures of scholastic achievement are more susceptible to cultural influences (family environment) than scores on IQ tests proper.  This was seen in the Minnesota Transracial adoption study.

Your Lying Eyes said...

I find this all very plausible - except that they seem to show too great a closing of the racial gap from what I've seen. The second graph above, for example, implies a B/W racial gap of < .7. But that's not what I've found looking at NAEP results. The gap has been shrinking, but very modestly. Similarly, the SAT Math gaps continue to fall around 1 s.d.

I would think that the big news from this article would be the dramatically shrinking racial gap - but I haven't seen any other evidence of this. The appendix doesn't help clarify things very much.

Anyone else find this surprising or have any insights on they're findings on the dramatically shrinking racial gap?

steve hsu said...

It seems clear to me that many more white, upper class Americans are interested in elite higher ed, and are willing to do what it takes to prepare their kids for the admissions battle, than 20 or 30 years ago.

JustinLoe said...

On a good note:
"Amid concerns about the lagging math and science performance of American children, American adults are actually scoring higher than they did 20 years ago on a widely used index of civic scientific literacy, according to a University of Michigan researcher"

Iamexpert said...

According to rushton and Jensen, the b/w gap in the U.S. has not decreased at all within the last 50 years. They even suspect that true b/w gap in the U.S. might actually be 1.5 SD instead of the 1 SD gap traditionally reported because the most disadvantaged blacks in the inner-city and rural south get excluded from the national norms.

JustinLoe said...

I don't think the US ever ranked high in terms of its per capita science graduation rates.

LondonYoung said...

Steve - this is achievement of the children based on parents' income, right?
Have you posted anything up comparing achievement of children to achievement of parents with income as the third variable?
The question being, obviously, "is this just IQ aligning more with income over time?"
Parents contribute both genes and money to their kids ...

Jean Huiskamps said...

" to a first approximation, there is a natural competitor pool that grew together with the Asian population"

Reminds me of a joke I saw on 9gag recently:


It's becoming a meme.

Steve Sailer said...

Jensen found big declines in W-B gap with ending of Jim Crow. Since then ...

Iamexpert said...

I don't think Jensen believes there were any decline in the W-B gap with the ending of Jim Crow.  On page 331 of "The g Factor" he writes:

"If the Flynn Effect is caused by environmental factors, it is most remarkable that a steady rise in the population's average test scores over a period of fifty or sixty years has had no effect on the mean IQ difference between blacks and whites, which has remained at about 1 SD since World War I.  This era has been one of steadily diminishing disparities between blacks and whites in educational, social, and economic opportunities,.  Yet the general upward secular trend in the overall population level of mental test scores has not changed the standardized difference between the mean test scores of blacks and whites."

Of course "The g Factor" was written back in 1998.  Since then Jensen and Rushton found fresh evidence to also show no narrowing from 1954 to as recently as 2008:

In order to re-examine the Black–White differences over the
last 54 years, we calculate mean Black IQs from the formula
IQ=MA/CA×100, with the White mean set at 100. From the
1954 Georgia study (Osborne, 1967, p. 385), the mean IQ for
Black 8th graders (14-year-olds) was 86 (12/14×100), and in
1965, 81 (11.3/14×100). From the 1966 Coleman Report, the
mean IQ for Black 12-year-olds was 87 (10.4/12×100); for 15-
year-olds, 84 (12.6/15×100); and for 18-year-olds, 82 (14.7/
18×100). Fromthe 1975 NAEP tests, the mean IQ for Black 13-
year-olds was 70 (9/13×100), and for 17-year-olds, 71 (12/
17×100); from the 2008 NAEP tests, for Black 13-year-olds, 85
(11/13×100); and for 17-year-olds, 77 (13/17×100). These
results indicate no Black gain in either mean IQ or in educational
achievement for over 50 years.

steve hsu said...

This is childhood performance, which tends to be less heritable (more subject to environmental influence) than adult ability. Obviously genes play a role here as well -- it would be nice to see a 90/10 analysis of the parents :-)

LondonYoung said...

Grrrr ... because, of course, what I want to see is a study of how much "parental money alone" helps in descendants' life outcomes.  Factoring the problem of "unequal at birth" into "unequal due to genes" and "unequal due to inherited resources" will tell us a lot about the nature of societal struggles to come ...  The current view of SCOTUS, as voiced by Sandra Day O'Connor, copes only with the latter ... no plan yet for the former ...

Carney3 said...

SOME of the gap is/was environmental. But not all, as we have seen.

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