[foobar2020]

> Poles and Italian immigrants in the US raised their average IQ scores over the 1st half of the 20th century -- by over 15 points!

So did everyone else: https://en.wikipedia.org/wiki/Flynn_effect

3 points per decade = 15 points per 50 years. So this shows that immigration to the US had no impact on the IQ of this group.

Whole developed world has very similar IQ levels to United States, except for China, Japan, Korea which have higher average levels: https://iq-research.info/en/average-iq-by-country

[philwelch]

There are also a lot of very boring explanations for this. It turns out that good nutrition and avoiding lead poisoning (two major improvements in quality of life in developed countries in the 20th century) both lead to higher IQ.

[foobar2020]

Right right, I'm not sure anyone really knows why this happens.

My point is that 15 points per half-decade is just baseline. Doesn't mean we've picked up any useful correlation.

[stcredzero]

Doesn't mean we've picked up any useful correlation.

There are US sub-populations that have lagged. Genetics does not explain this, as overseas populations with the same genetics have not lagged.

[foobar2020]

Interesting. Do you have any sources where I could read about it?

Flynn effect is fascinating me - if it holds in the future we'll have, in developed nations, an average IQ of 130 (by today's standards) in 100 years. That's a LOT. It'd, roughly, mean that ~17% of people would be capable of graduating from today's Ivy League schools without problems (145 IQ or more). And there would still be the (new) top 0.5%. But whether it will hold is anyone's guess.

[stcredzero]

The Flynn Effect in Britain, Kenya, and Dominica:

Black IQ Gains in Britain, Kenya and Dominica

https://robertlindsay.wordpress.com/2011/01/19/black-iq-gain...

Eyeferth Study -- Children of Black American servicemen in Germany had the same average IQ as German children:

https://en.wikipedia.org/wiki/Eyferth_study

Thomas Sowell's survey of the work of Arthur Jensen and others. Basically, the patterns around the Flynn Effect are everywhere, and it shows up in Black populations as well. There is also a mention of a study of Black children raised by white families, which found the average IQ of that population to be 106.

https://www.nytimes.com/1977/03/27/archives/new-light-on-bla...

[simonsarris]

Flynn most recently has been giving talks about the reverse Flynn effect.

It isn't holding, especially in isolated populations that are easy to measure like Iceland.

[MagnumOpus]

Flynn effect stopped in the 1980s and even reversed since then.

Most probably it was due to the increasing ubiquity of K-12 education and fewer bad childrearing habits (smoking/drinking while pregnant, lead exposure, no vitamins).

[stcredzero]

> So did everyone else: https://en.wikipedia.org/wiki/Flynn_effect .

Then, look at differentials in the US that came after 1950.