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points by fliglr 22 hours ago | 0 comments

IQ differences between the racial groups is one of the most, if not the most, replicated findings in psychology.

Difference in IQ test scores between racial groups in the United States is established and replicated. Differences in innate intelligence are not. It's not hard to intuit the difference; you just ask yourself, "I wonder what else could have been different between racial groups in the United States at the time these surveys were conducted?".

[–] mike_hearn 10 hours ago

It replicates worldwide, it's not a US thing.

[–] tptacek 9 hours ago

What do you mean "it replicates worldwide"? What replication are you referring to?

[–] fliglr 4 hours ago

IQ differences between ethnic/population groups/racial groups. It's not only a US phenomenon

[–] tptacek 4 hours ago

I don't think it's a US phenomenon in particular; I'm saying we have data about the US, and not about the rest of the world.

[–] fliglr 3 hours ago

Then you haven't looked

[–] tptacek 3 hours ago

People tend to say this before citing "IQ and the Wealth of Nations" or something derived from it.

[–] mjanx123 3 hours ago

The US racial groups are US specific. The bundling of different ethnicities into a race (like grouping high pigmented out of Africa with Africans instead of with low pigmented out of Africa) is silly.

[–] graemep 21 hours ago

Are they consistent across time and cultures? Are they corrected for differences in health, education, culture, wealth, etc? How big are racial differences compared to differences between people from different social classes?

How do you define racial groups? its something that constantly shifts. I have an encyclopedia for the 1950s that defines South Asians as "Caucasoid" which is not how most people now think.

[–] DC-3 20 hours ago

You can do a dimensionality reduction on genetic variants and certain recognisable groups fall pretty clearly out of the data.

[–] graemep 20 hours ago

Do those groups relate closely to what people generally mean by race? Race as defined in which culture? I know from personal experience that its not the same definitions across cultures. How big are those differences compared to differences within racial groups?

[–] DC-3 19 hours ago

Take a look yourself.

https://upload.wikimedia.org/wikipedia/commons/f/f9/Principa...

Obviously some racial groups which are heavily socially constructed are not borne out by the data. There's no cluster for 'Latinos'. But in general I think there is quite a high correspondence with race as it is constructed in society and culture.

[–] ComposedPattern 17 hours ago

So on that graph, the distance between East and West Africans is about as great as the distance between Indians and Europeans. Somalis are closer to East Asians than they are to Southern African Khoisan people. Bedouin Arabs and Southern Europeans are closer to each other than either are to North Africans or Northern Europeans.

There are certainly some cases where the genetic data matches conventional thinking about race, but also many where they flatly contradict. It also suggests that saying something like "white people are genetically smarter on average than black people" is highly suspect. The group of people that we call "black" has a greater range of genetic profiles than the rest of the world put together, and the group we call "white" is kind of confused—to be genetically meaningful it would probably need to either include North Africans and Arabs or exclude Southern Europeans.

[–] mjanx123 2 hours ago

The social "white race" (declared superior to other "races" to rationalize and justify the UK empire parasitation on a half of the world) corresponds with the northwestern european genetic cluster (with the exclusion of the Irish who were conquered by the UK and not considered white despite being the least pigmented population in the world). The intra european clusters are an ultra fine genetic resolution analysis. The genes that in todays population correlate with high IQ spread from ~2000bc likely with the Iran-neolithic genetic component.

[–] graemep 15 hours ago

Where are South and SE Asians on that?

Looking at this

https://en.wikipedia.org/wiki/Human_genetic_variation#/media...

It looks as though there are two rough clusters, Africans and everyone else, with Europeans and Middle Easterners in the intersection. Pretty much reflecting geography.

[–] jcranmer 15 hours ago

There is more genetic diversity among Africans than among all of the non-African groups. And yet I haven't seen a racial typology that didn't lump all of the Africans into one race, very often while they're trying to declare differences between people in the same European cluster.

[–] ninjagoo 4 hours ago

> Take a look yourself.

> https://upload.wikimedia.org/wikipedia/commons/f/f9/Principa...

Is there a reason you're sharing a random uploaded file instead of a "vetted" actual Wikipedia article?

Is there any reason to think this is from a real or valid scientific study?

[–] fliglr 4 hours ago

Well, one way of looking at it is, asking: to what extent does biological population correlate with self-identified race. The answer is, very much so.

[–] snowwrestler 15 hours ago

Of course it is, creating that difference was the basis for IQ testing in the first place.

[–] tsimionescu 19 hours ago

Based almost entirely on racist studies, including some famous ones that were comparing white and black school children in apartheid South Africa. I wonder if there may have been some confounding variables there, but surely this is just my bias.

Plus, none of these studies actually spend the money to do any genetic testing, they simply assign people to "white" or "black" race based almost always on skin color (which, since the gene for dark skin is dominant, is a very poor marker of actual genetic similarity - the great grandchild of a dark-skinned person with otherwise only white-skinned relatives can still be dark-skinned).

Edit: and I'm not even mentioning the obvious publication bias, as essentially only racists care about this race vs intelligence discussion, at least enough to invest in creating studies about it. Plus the fact that IQ itself is actually a very problematic measure, when applied beyond its actual medical use (quantifying mental disability).

[–] sjducb 17 hours ago

We care about racial differences in outcomes that are correlated to IQ, such as employment and imprisonment.

What if some of the observed racial differences were caused by a lack of vitimin D, due to darker skin photosynthesising less of it? Vitamin D is essential for brain development. Black people in northern climates get less of it than evolution intended. This lack of vitamin D might be causing reduced brain development in black populations. If that is true, we could fix the prison crisis and racial IQ differences with a pill!

Sadly we don’t know because you can’t do the research to test the hypothesis.

If we block all research into a problem then we can’t solve it.

If you actually care about fixing a problem then we should bring all available tools to fix and solve it.

[–] vintermann 15 hours ago

It's a good tool if you want to rank people, it's a bad tool if you want to help people. IQ tests couldn't (and can't) even detect dyslexia, a specific disability which you can get help with, which was known even in Terman's time. IQ tests by design throw out all information which could complicate ranking people. If your goal is to help, why would you measure people with a tool which can't tell the difference between dyslexia and concussion?

IQ tests have been revised several times to address things like that, like that they "unfairly" penalize dyslexia, or that they had lots of questions which were easier for people of specific social backgrounds. Every time they were, they naturally became less "predictive", since both dyslexia and not belonging to the California white upper middle class give you pretty obvious disadvantages in life outcomes.

So don't waste time on IQ, and don't waste time on other academic culture war BS either.

[–] tptacek 12 hours ago

Wait, this is the opposite of reality. IQ is in fact a useful tool (in a battery of other tools) for helping diagnose cognitive deficits and learning disabilities. That's what it's good for: as a clinical tool. It's in fact terrible for ranking people.

[–] vintermann 10 hours ago

Well that's what it was used for! Do your history homework, mr. clinician!

Tell me then, if someone scored low on a text-based IQ test and that's all you know, how do you tell if it was caused by dyslexia or concussion? I guess you break out that "battery of other tools"? What does IQ tests give you that those other tools don't give better?

Oh, I know one. An excuse to write someone off as simply stupid. An excuse to _stop looking_ for the things which might have helped them. Which is what it was historically used for.

[–] sjducb 15 hours ago

If you can’t study IQ how do you demonstrate that lead poisoning causes reduced intelligence?

The research to ban lead in fuel relied on measuring IQ and measuring lead exposure, then showing a correlation between the two.

At the population level IQ is a very useful tool.

[–] jcranmer 15 hours ago

IQ is a very bad tool for measuring populations. That's because IQ is definitionally designed to force a population to adhere a particular metric: a bell curve distribution, with the median at 100 and the standard deviation of 10. Whatever the thing you're measuring is--and there's good reason to think it's not "intelligence"--you're crunching and distorting that measurement to get the number at the end of it to force the population to adhere to a standard distribution.

We don't have a good model of what intelligence is. But since IQ studies are fairly common, there's a lot of data collected that uses IQ, and since it IQ looks vaguely like "intelligence," a lot of researchers who are motivated to find reasons to declare particular people intelligent or unintelligent are more than happy to use that data to support their claims.

[–] sjducb 14 hours ago

Did you even read my comment?

Answer this question:

> If you can’t study IQ how do you demonstrate that lead poisoning causes reduced intelligence?

[–] jcranmer 12 hours ago

The answer to that question should be blindingly obvious: you don't.

It should be clearly evident that trying to use IQ to establish that "<insert ethnic group here> are stupid" is bad science. It's the same sort of science to establish that "<insert environmental factor here> causes stupidity," so we also need to reject it even if the environmental factor is clearly something problematic. The problem isn't the conclusion, it's the methodology.

[–] ogogmad 16 hours ago

> correlated to

Correlation measures whether Y=mX+c holds with small error. I sometimes think that many people unknowingly assume that all dependencies are somehow straight-line ones. This is distinct however from "linear approximations" in physics, which can at least be justified sometimes.

I also suspect that correlations of 0.5 or lower are often just statistical noise.

[–] sjducb 15 hours ago

I don’t see how your reply relates to my comment. At no point do I say that any correlations are linear, nor does my argument depend on linear correlations.

Fundamentally my argument is maybe science can solve a problem, let’s at least try.

[–] mjanx123 2 hours ago

The US never truly abolished slavery, it turned it into a punishment, and started sending black people into prison en masse. There is no prison crisis, in fact the prison industry is flourishing like never before!

[–] fliglr 4 hours ago

You are hilariously wrong. There is a mountain of evidence of racial differences in IQ scores, why don't you familiarize yourself with the literature before spouting off nonsense about it?

Question: is there any kind of evidence, that hypothetically did show a racial difference, that you would not label as racist?