Commenter pumpkinhead made a series of points about Donald Trump’s IQ that I thought were worth responding to in a new article.

1. SAT scores correlate highly with IQ, I believe the correlation is around 0.86. There are SAT to IQ conversion charts online. So using that as a metric we can work out his IQ based on the Wharton school minimum SAT requirements. It is not clear what his score is or whether he even has any but he did gain entry(albeit as a transfer student) which is one more piece of “evidence” in his favor.
2. According to this, https://www.iqmindware.com/blog/the-bell-curve-cognitive-elites/
the average IQ of the top 12 universities in the country is around 142.

The 142 figure is from The Bell Curve by Richard Herrnstein and Charles Murray. It’s based on the fact that elite school students scored 2.8 standard deviations above the general U.S. population on the verbal SAT, which equates to 142 on the IQ scale.  For years I’ve argued that this is a massive overestimate because you get a selection bias effect when you measure the IQs of a group by the very test used to select them.  Thus I was happy to see that buried in the notes on page 712 of The Bell Curve, they state that the correlation between verbal SAT and IQ is 0.65, and so students from elite schools should regress about a third of the way to the mean.  This would reduce them from +2.8 SD to 0.65(+2.8 SD) = +1.82 SD or IQ 127.  And that’s more or less what we see in a study of Harvard and Dartmouth students.

Now there are studies where the SAT correlates much higher with official IQ tests or g (general intelligence) in academically homogenous samples, but if you gave the SAT to all U.S. 17-year-olds (including high school dropouts with no test prep & little interest or knowledge in algebra) the g loading might drop a lot.

Of course in Trump’s case, the SAT would be a valid proxy for his IQ if it were discovered randomly,  but the average SAT of elite students in general is an inflated IQ proxy because the only reason we know their average score on the SAT (and not some other test) is precisely because they did well enough to get into an elite school; thus it’s not a random sample of their ability and thus we use regression to predict their score on a random test.

3. He is a billionaire, albeit with a good head start but he has basically multiplied his bankroll/inheritance 100x over in his lifetime. That is nothing to scoff at especially since a lot of people squander their entire inheritance in their lifetime.

Just yesterday The New York Times reported that Trump was given \$413 million in today’s money from his father.  As of Oct 3. 2018, Forbes estimates his real time net worth to be \$3.1 billion so I’d say he multiplied his inheritance by 7.5 times.  That’s still quite impressive, but nowhere near 100 times.

4. He comes from the cutthroat business/real estate world AND he managed to become a successful entertainment personality. In retrospect it all may have played into his long term plan to win the presidency. This may be more a testament to his grit and social status/contacts but if by some happenstance it is easy to get in(entertainment & business worlds), i’m pretty sure it is exceedingly hard to stay in, a certain level of intelligence is a must. Any way you slice it though, that is no small feat.

I’ll grant him that.  I define intelligence as the cognitive ability to adapt (turn situations to your advantage) and there’s virtually no public figure who has made it to the top in three completely different domains (real-estate,  media, and politics).

But at the same time, because there are so many factors that can influence life outcomes, the correlation between IQ and worldly success (money, power, status) is only moderate (0.5 at the most) and Trump had a huge head-start.

His father was one of the 400 richest Americans (and self-made) and such people average IQs around 132, which means their kids have IQs around 116 (assuming about a 0.5 correlation between father and child).  His father was about 4.73 standard deviations above average in money (one in a million level) and given the 0.47 correlation between father and son income in the U.S., we’d expect Trump to have been 4.73(0.47) = +2.37 SD in income (and perhaps worldly success in general).  Instead, as both a multi-billionaire and a President, he’s arguably the most successful of all 215 million American adults (age 25+) and thus +5.73 SD in worldly success, which is 3 SD higher than expected.

Given a 0.5 correlation between IQ and worldly success and assuming it applies within social classes, that would give him an expected IQ that is 3 SD(0.5) = 1.5 SD above that of other trust fund babies (average IQ 116) and thus IQ 139.

5. Interviews from when he was younger reveal a much more linguistically and cognitively adept individual. His fluid intelligence has taken a hit with age but that is to be expected. IMO certain aspects of his working memory took the biggest hit.

Indeed, which is why although his biggest accomplishment (becoming president) came in old age, I would only apply the above IQ estimate to his younger years.  Given the imperfect stability of IQ over the life time, his current score could be wildly different (even adjusting for age).

6. He won the presidency as a complete outsider, going up against the media, corporate, and deep state favorite during a time of “first black”, “first female”(what’s next, first gay?) national infatuation(very un-meritocratic but i’m glad logic prevailed). In my view that is unheard of in the last 100 years, or maybe ever in US politics.

He certainly showed incredible adaptability in becoming President.  Being President?  Not so much.

7. The reason I give him a high math/visual IQ is because he seems to be the sort of person that thinks in pictures. People that think in images formulate their thoughts in that way and then try to put words to those images. If their verbal is not too high and old age has impacted their working memory even further, they struggle to find the words while the conceptualizing may be stellar. They then try to make up for this and convey their competence(of which they are internally sure of) in a braggadocious way. Of course not all big ego types are of this sort, one has to look at all the evidence…which is found in the obvious competence it would take to gain a degree in business from Wharton, a degree that leans far more into math/logical and visual acuity than it does linguistic.

8. In any case I think that his greatest asset is his interpersonal intelligence a must for any business/real estate entrepreneur let alone a president of the US. This won’t be measured by any IQ test but given the high correlation between respective facets of intelligence it is not much of a stretch to think that the underlying cognitive foundation that allows one to excel in one area can lend itself to facilitating excellence in other areas too(though admittedly this is not a strict rule).
So using all the above I would say there is enough evidence to safely say that he is more likely >125 than he is <125. I’ve settled at 140(a far cry from the reported 156) and while I admit I may be wrong, I doubt I am wrong by much. So peak 140, current 130.

I can agree with a peak IQ of 140.  A current IQ of 130 sounds way too generous (even adjusting for age) in my humble opinion but anything’s possible.  Let’s see if he’s smart enough to get re-elected.