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Brain size=IQ level theory (Blacks vs Whites & Asians)

Human Anatomy, Physiology, and Medicine. Anything human!

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Postby wildfunguy » Thu Jul 31, 2014 10:29 pm

I was wrong about the adoption studies.

Adoption Studies

In addition to prenatal environment, the studies also fail to control for social environment.

https://en.wikipedia.org/wiki/Minnesota ... dy#Results
table of the Flynn-effect corrected results, 3rd table under Results...
It's interesting that the adopted children had a larger drop in IQ from 7 to 17, but the average drop for the adopted non-whites ((55*12.2+12*4.9+21*7.7)/(55+12+21)=10.1) was equal the drop for the adopted whites (10.1). The drop was smaller for the adopted blacks specifically (7.7), which could be due to the decline with age in the effect of "pre-adoption variables".
According to the Wikipedia article, Loehlin suggested prenatal effects, noting that among the adopted interracials, 66 of their 68 biological mothers were white. You'll notice that this group's IQ was only below the adopted whites by 6 and 8 IQ points, whereas the adopted blacks were below by 20 and 18 IQ points, more than twice below at age 17 and nearly four-times below at age 7.

Suffice it to say, the adoption studies results were influenced by many non-genetic variables, and it shouldn't be surprising that the adopted blacks still scored lower on IQ tests.
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Postby josem » Mon Oct 27, 2014 9:12 pm

I think there is no correlation between brain size and IQ level. If compare brains of whale and elephant with humans, ours is too small. But we have very high intelligence. I think some connections between neurons or some unknown factors determine intelligence.
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Postby Seth90210 » Wed Feb 25, 2015 2:37 am

CandyTon wrote:MRI scan of human brains have shown that the brains of different races are of different sizes.

The Worldwide Pattern of IQ Scores. East Asians average higher on IQ tests than Whites, both in the U. S. and in Asia, even though IQ tests were developed for use in the Euro-American culture. Around the world, the average IQ for East Asians centers around 106; for Whites, about 100; and for Blacks about 85 in the U.S. and 70 in sub-Saharan Africa.

although environment is the major factor in determining IQ, genes (ie as in bigger brains which contribute to some innate intelligence) play a small- but not empirical- role. do not forget that Asians scored 6 points ahead due to their lower and unrepresented sample of selected subjects and higher visuospatial intelligence, but very average to below average verbal intelligence (a cause most likely due to selective breeding). in any case, there are other factors that determine intelligence- social, emotional, rhythmic, and others- that are often neglected by researchers, making IQ tests less credible. in the end, the way one is raised and their level of nourishment and nurture are major contributors to their intelligence.

1. There's no such thing as a "black brain." So your brain size claim has no validity.

2. The 70 IQ claim for Africans is a well-known fraud.
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