Reddit mentions of The testing of Negro intelligence

3/3


Another argument for IQ being genetic is that IQ of mixed race black/white people is intermediate that of the black and white average.

Obviously there are environmental factors that impact IQ. But they don't have as much an impact as people think.

Overall it seems that intelligence is about 80% nature 20% environment.


Lets compare the IQ of black populations to poorer populations of other races. Using GDP per capita data from World bank as well as Census data and IQ data from this study you find that blacks in America have a GDP per capita of 20,458 and an average IQ of 85. There are many other countries with few blacks that have lower GDPs per capita and higher IQ. Estonia, Chezk Republic, Lithuania, Latvia, Poland, Hungary, Croatia, Russia, Romania, Belarus, Vietnam, Ukraine, Mongolia, Serbia, China, and others all have lower GDPs and higher average IQs.

Now lets look at SAT scores. One study found that if average SAT scores of high school students are broken down by their parent’s socioeconomic status or SES (for both Blacks and Whites), Whites from families who earn less than $20,000 a year do just as well on the SAT as Blacks from families that earn more than $200,000 a year. Other studies have found that Whites from severely impoverished families who earn under $10,000 a year tend to have higher SAT scores than Blacks who earn over $100,000 a year. Another source. And another.

Another thing that's interesting, is that the richer people you compare, the larger that Black-White IQ gap becomes. In this book 32 studies were analyzed and found a mean Black-White IQ gap of 12 points between people of low SES and 20.3 points between people of high SES. This has been replicated multiple other times, including in Murray's The Bell Curve.

Now lets look at racial and IQ difference over time. The U.S. Census began collecting information on individuals income in 1939. Since then, Black wage relative to White wage have risen from 44% to 67% in 1989. Using data from the US Census Bureau between the 1950’s and 2014, there was a dramatic reduction in the size of the Black White income gap. The median income of Whites went from 2.4 time larger than the median Black income during the 1950’s, to only around 1.3 times larger in 2014. Rates of post-secondary educational attainment revealed the exact same pattern. In 1940, Whites were nearly 4 time more likely than Blacks to have a Bachelor’s degree or higher. However, as of 2014, Whites were only 1.5 times more likely than Blacks to have a BA or higher. All and all, the historical trends reveal huge reductions in the education and income gaps between Blacks and Whites.

But during this time, the white/black IQ gap hasn't really changed. In this book it's reported that IQ testing during the first world war gave Blacks a mean IQ of 83. Today the average IQ of blacks is 85. Thus, the Black-White IQ gap has been reduced by 2 points during a time period in which the black/white socio-economic gap has been reduced by at least 50%.

I really don't understand why people have such a hard time accepting that intelligence is largely determined by genetics. Environment certainly plays a role, but it's not as large as you've been led to believe.

>Which of course is from 1996 (23 years old),

Indeed, but it's still the gold standard and new discussions on the topic reference it as the conclusions still hold true today.

>and talks about direct evidence, not evidence in general. Such desired direct evidence was published first in 2013, and has since been updated a number of times as new GWASs come out. The results don't really change much, though there are issues with this approach. Most recent publication is https://www.mdpi.com/2624-8611/1/1/5. A slightly less direct approach is to use admixture analysis. 20th century studies of this are mostly supportive of genetic causation (Shuey reviewed these in 1966), and the only published modern study is https://www.mdpi.com/2624-8611/1/1/1. There are a few more of these in review, and more powerful methods (local admixture, GWASs on sibling pairs) exist and studies using these are under way.
>
>So plenty of progress since 1996 and its basically all pointing in the same way.

Those "studies" you link to are essays published in the pseudojournal Psych which is known for just pushing racist nonsense and having practically no quality control.

Specifically, the author you link has posted numbers articles in the "journal" demonstrating the truth of psychic powers.

So I agree that there is new and exciting evidence on the topic of race and IQ, as long as we qualify it by saying that the evidence is of the same quality as the evidence for telekinesis.

Which of course is from 1996 (23 years old), and talks about direct evidence, not evidence in general. Such desired direct evidence was published first in 2013, and has since been updated a number of times as new GWASs come out. The results don't really change much, though there are issues with this approach. Most recent publication is https://www.mdpi.com/2624-8611/1/1/5. A slightly less direct approach is to use admixture analysis. 20th century studies of this are mostly supportive of genetic causation (Shuey reviewed these in 1966), and the only published modern study is https://www.mdpi.com/2624-8611/1/1/1. There are a few more of these in review, and more powerful methods (local admixture, GWASs on sibling pairs) exist and studies using these are under way.

So plenty of progress since 1996 and its basically all pointing in the same way.