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PurpleAlien47 t1_irel38i wrote

Reply to comment by jonathot12 in TIL A 2017 study found that the introduction of iodized salt in 1924 raised the IQ for the one-quarter of the population most deficient in iodine. by kstinfo

>To figure out the effects, the researchers used the data from the Army General Classi cation Test (AGCT) given to people who enlisted during World War 2. That covers a wide group of men born precisely at the time iodized salt was introduced (1920-1927), which allowed comparison of low and high iodine areas.
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>The Air Force received enlistees who scored significantly higher on the AGCT, and the number of men who scored well and went to the Air Force from low iodine areas dramatically increased after iodized salt was introduced. The estimates of intelligence increases are based on that data.

Source: https://www.businessinsider.com/iodization-effect-on-iq-2013-7

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Gemmabeta t1_irf7jkd wrote

> AGCT

Hasn't it been shown many times that the AGCT is a complete bullshit way to measure innate intelligence because most of the questions revolve around trivia and school knowledge--which meant that rural men and African Americans of the era were classified as borderline mentally handicapped when they were simply unschooled.

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PurpleAlien47 t1_irfhjd3 wrote

Not sure, and unfortunately the paper Business Insider is citing doesn't seems to go into detail about how they're mapping these AGCT scores onto IQ. That information is probably in one of the paper's own references.

They do however mention they weren't able to find a significant correlation between AGCT scores and level of education in this particular dataset:

>While surprising, this finding is consistent with the fact that in our data we find a very weak correlation between AGCT scores and education. Specifically, the correlation between AGCT scores and graduation from high school is 14%, while the correlation between AGCT scores and having one year of college or more is just 9%.

https://www.nber.org/system/files/working_papers/w19233/w19233.pdf

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Gemmabeta t1_irfhx22 wrote

I mean, the difference here is they are comparing people with considerable schooling with people who has even more schooling (high school dropouts vs college students).

I am talking about people who are entirely unschooled or nearly so (of which there were many back in the World War I era).

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