9 Comments

"Another line of evidence is that the blacks have a smaller standard deviation for IQ than whites (Jensen 1973, 212)."

Don't think so. Your own table from our study above shows slightly larger Black SD.

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What percentage of the b-w gap are PGS able to predict? How do we account for differing r2 for blacks and whites on pgs_edu when predicting the iq gap mediated by allele variants

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https://russellwarne.com/2022/12/17/irish-iq-the-massive-rise-that-never-happened/

the irish iq has always been relatively high (98)

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"Sibling regression toward the mean is one line: a black sibling of someone with an IQ of 120 will have an IQ of about 100, while a white sibling would have an IQ of about 110 (Jensen 1973, 118). "

Interesting. Is there also data about the IQ of the parents of this individual with 120 IQ?

What is the distribution of individuals with 120+ IQ in the black community?

If the individuals are a super minority, then the genetic impact might be less pronounced, as scarcity might limit reproduction partners.

If both parents have an IQ above 120, I would be curious to see if this sibling regression relationships remain the same.

I know that some level of endogamy exists between social classes, which leads to IQ wealth being concentrated within communities. Elites marry other elites, and high IQ individuals rarely interact outside similar groups. I wonder if the observed sibling regression is based on the expectation that this social endogamy is the same across both communities.

I also question the actual accuracy of income as a proxy for measuring sibling regression within the black community - DEI and affirmative action type interventions must have an outsize effect on the output on that analysis. I would be curious to know how one would correct for such interventions.

Really though, I'm curious to see what newer data looks like. A lot of the African Elite professionals have migrated to the west over the last twenty years, I expect changes, at least to our understanding of heritability, race and environment.

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Your estimates of heritability are hugely exaggerated. While behavior geneticists believed that IQ was 80% heritable in the 90s, more recent research has shown that the heritability has to be much lower. IQ scores are rising all the time, a fact that isn't compatible with an 80% heritability. Adoption studies have shown massive IQ gains for children. New theories of environmental influence on IQ have become increasingly accepted. Read about it here: https://open.substack.com/pub/eclecticinquiries/p/on-race-racism-iq-and-heritability?r=4952v2&utm_campaign=post&utm_medium=web

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I understand why people can have concerns over this question. But it is possible, in a free society, that defends civil rights, to have this discussion safely, without threatening anyone. We all live gifted, and burdened with our innate traits. There are better and worse traits. We all know that about ourselves, our loved ones, and everyone else. And we see the gifts and lesions of each other. I think most of us do appreciate the diversity that blesses and plagues each of us. But a few traits separate us- the honesty and courage to admit these things.

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Two of the findings you reference puzzle me.

First:

"For example, the black-white IQ gap remains roughly the same at all income levels (Herrnstein & Murray 1994, 288), meaning lower group income couldn’t be the cause."

Doesn't that mean that although IQ predicts income (to some degree), Blacks on average, require a lower IQ score than do whites to achieve the same level of income? And wouldn't that then mean that the test actually IS biased -- such that a lower score for African Americans ultimately has the same consequences for life success as a higher score for whites? Am I wrong?

and, second:

"When they have the same IQ as whites, blacks are more likely than whites to graduate from college and to attain a high status occupation. "

Again (same basic argument as above regarding wealth). Doesn't this finding mean that African Americans with a lower IQ score are as academically able as whites with a somewhat higher IQ score? That IS what the sentence I quoted means, isn't it? If not -- then what DOES it mean?? And if I've interpreted the finding correctly, then wouldn't that mean there is a degree of bias in the test, such that lower IQ scores for African Americans are predictive of the same degree of academic and life success as high scores for whites? What am I missing here?

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You misunderstand. One association is one own's income vs IQ (when adult), other is parental income vs child IQ.

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There were too many comments on your twitter thread to read. A number of people pointed this out and I agree. The IQ gap between black and white Americans is likely entirely genetic. There are no starving people in the US nor do we have lead paint or any widespread pollutants.

It's like sex differences. The more egalitarian a society becomes, the more of the differences we see are genetic. Women can be anything in the US or Western Europe. Yet so few of them go into computer science or engineering. Instead a poor country like Romania has a lot of women engineers.

But the IQ gap between Sub Saharan Africans in Africa and whites probably has a sizable environmental explanation. Giving the Raven's test to children after they spend a day mining cobalt is not exact good data right? There's still a lot of pollution in their drinking water also.

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