Article on IQ: The Inappropriately Excluded

buybuydandavis

I saw an article on high IQ people being excluded from elite professions. Because the site seemed to have a particular agenda related to the article, I wanted to check here for other independent supporting evidence for the claim.

Their fundamental claim seems to be that P(elite profession|IQ) peaks at 133 and decreases thereafter, and goes do to 3% of peak at 150. If true, I'd find that pretty shocking.

They indicate this diminishing probability of "success" at the high tail of the IQ distribution as a known effect. Anyone got other studies on this?

The Inappropriately Excluded

By dividing the distribution function of the elite professions' IQ by that of the general population, we can calculate the relative probability that a person of any given IQ will enter and remain in an intellectually elite profession. We find that the probability increases to about 133 and then begins to fall. By 140 it has fallen by about 1/3 and by 150 it has fallen by about 97%. In other words, for some reason, the 140s are really tough on one's prospects for joining an intellectually elite profession. It seems that people with IQs over 140 are being systematically, and likely inappropriately, excluded.

Their fundamental claim seems to be that P(elite profession|IQ) peaks at 133 and decreases thereafter, and goes do to 3% of peak at 150. If true, I'd find that pretty shocking.

They indicate this diminishing probability of "success" at the high tail of the IQ distribution as a known effect. Anyone got other studies on this?

The Inappropriately Excluded

By dividing the distribution function of the elite professions' IQ by that of the general population, we can calculate the relative probability that a person of any given IQ will enter and remain in an intellectually elite profession. We find that the probability increases to about 133 and then begins to fall. By 140 it has fallen by about 1/3 and by 150 it has fallen by about 97%. In other words, for some reason, the 140s are really tough on one's prospects for joining an intellectually elite profession. It seems that people with IQs over 140 are being systematically, and likely inappropriately, excluded.

One interpretation I've seen is that ~130 is about as high as a human brain can get while still using basically the same architecture as an IQ 100 brain. The further beyond that you get, the more you're using significantly different systems. These differences may tend to be autism-related, such that the higher IQ comes at the expense of impairments.

What definition of "autism" would you use in this case?

17gwern10y

My reading of the behavioral genetics literature is that high intelligence being driven by rare autism variants is looking unlikely. DeFries-Fulker extremes analyses like "Thinking positively: The genetics of high intelligence", Shakeshaft et al 2015 aren't consistent with the (relatively) high end being due to rare variants (but are consistent with the low end being due to rare variants) and current attempts to find rare variants enriched in the very high IQ with large effect sizes have turned up nothing: "A genome-wide analysis of putative functional and exonic variation associated with extremely high intelligence", Spain et al 2015. There is also an autism heritability observed in the GCTAs/LD score regression using only common SNPs (>=1% population frequency), along with a positive autism/intelligence genetic correlation, which undermines that idea. My speculation at this point is that Spearman's law of diminishing returns is - based on all the genetic correlations with intelligence which have piled up and the current trends in brain imaging studies finding brain volume/thickness & global connectivity & white-matter integrity & connection speed to be the best predictors of intelligence - is due to intelligence reflecting a bottleneck between all the regions of the brain communicating to solve problems and that as the global communication becomes closer to optimal due to better health & development, individual specialized brain regions start to become the bottleneck to higher performance and shrinking the g factor.