Lumifer comments on Rationality Quotes Thread January 2016 - Less Wrong
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Pardon my ignorance, but all the "intellect realism" theories seem like they can be charitably paraphrased as group X:
- has a different mean IQ than the general population and/or
- has a different standard deviation for IQ and/or
- has a significantly skewed distribution from the normal curve
I've seen claimed IQ means in the 80s for black Americans. Observationally, American public life includes many black people for whom I find it implausible that they aren't pretty smart - eg Clarence Thomas, Colin Powell, Condeleeza Rice.
If I assume no difference in std dev or skew in intelligence distribution, it seems to me that I observe too many intelligent black folks for the mean to be in the 80s. Moreover, adding an assumption that std dev is lower doesn't help - now the successful black folk are explained, but I don't observe enough extreme low IQ folk.
That's why I conclude some error exists in the assumption of an 80s mean IQ.
One and two, yes, but I haven't seen data that would indicate some population has a significant skew in its IQ distribution.
Why don't you do the numbers? The purely-black IQ mean is about 85, I believe. A great deal of American blacks have some admixture of whte genes, so I think the IQ average for US blacks is in high 80s, maybe 90. There are about 42m of them. So lets' try three standard deviations above the mean, IQ > 130-135, more or less. That would be about 0.13% of the population, so about 56,700 individuals. You'd actually expect a bit more because many people with a lot of white genes (which would push their expected IQ up) identify as black.
How many do you observe? :-/
You can also look at IQ proxies, like SAT. Here are 2015 scores by race -- LW sucks at formatting tables, but basically scores of whites (average ~530) are consistently about 100 points above the scores of blacks (average ~430). Asians score the highest.
African American mean IQ is typically measured at 85 to 90. Sub-Saharan African IQs are difficult to estimate because of a number of factors, but 85 is much higher than typical estimates.
First, 42 million includes children for who I doubt there is a public criteria we can agree on as proxy for intelligence. Second, I'm not sure IQ > 130 is .13%. Wikipedia suggests 1%.
Since those cut in opposite directions, let's pretend they wash out. I am comfortable asserting there are more than 60k black folks in the set of:
- senior military officers (colonel or greater)
- highly successful national public intellectuals (eg Powell, Coates, Rice)
- highly successful lawyers (Clarence Thomas is top 1% of lawyers)
- highly successful MDs & research PhDs (eg Neil DeGrasse Tyson).
- highly successful media/entertainment personalities (Sean "Diddy" Combs, Oprah, etc).
- highly successful technocrats (mayors / police chiefs / school superintendent in large metro areas)
The tail above three standard deviations for a normal distribution constitutes about 0.13% of the population.
Media/entertainment personalities can be oh so very dumb :-)
Otherwise, I am doubting your assertion. Do you have data?
Most IQ scales set the standard deviation at 15 points, not 10 points.
Yes, but we are starting from the mean which is 85 in this particular case.
Oh, I see. I was confused about what calculation you were doing; my apologies.
From personal experience, there are lots of dumb lawyers. When I say highly successful, I mean roughly the level of screening that occurs through promotion from fresh-out-of-academy lieutenant to colonel.
For reference, Clarence Thomas easily clears the bar I'm trying to set, as did Johnny Cochran before he died. For entertainers, it seems clear that talent isn't correlated with intelligence. But I think staying power requires some, so the ultra-successful are candidates.
For my broader argument, the categories I set out are potentially under-inclusive. There are lots of folks (like business people) not included in the categories I explicitly listed. We also haven't included any children, on the grounds that we don't agree on how to identify them.
Yeah, but it's all hand-waving. I see this if I squint this way and you see that if you squint that way...
You originally said
You, personally, observe too many? Is that statement true? Or do you merely expect to see many?
By convenience sampling in my personal life and observing public figures, I see a certain proportion of successful folk are black. Extrapolating from the proportion I see, 60k smart black folks is plausible. A much lower number is not plausible. What number of smart black folk should we expect to see if the mean were 85?
Public figures are what, a few dozen at most? So you rely on your personal sample and why in the world do you think that it's representative?
Let's take our favourite people -- Alice and Bob. Alice lives in rural Alabama. She knows zero smart black people and extrapolates her personal sample to "all black folk are stupid". Bob hails from Idaho and is an undergrad at Harvard -- 100% of black people he knows are very smart. He extrapolates his personal sample to "all black people are smart". Why is your sample any better than Alice's or Bob's?