Two measures—both alike in quackery
When I land in discussions of IQ, it is often manifestly clear that two thirds of the debaters have no clue about the topic. In an attempt to straighten out a few question marks, I will below present an analogy. The topic as a whole is far too wide for a single blog post, but I can recommend IQ Comparison Sitee and some of La Griffe du Lion’s writingse to those who want a basic introduction respectively some discussion of other aspects. (There is plenty of more material on the Internet, including academic papers. Google is your friend.)
Now, one of the most common ways of dismissing IQ is to point out that there are high-IQ people who have failed utterly and that there are low-IQ people who have succeeded—“obviously” IQ is just quackery.
IMO, a very appropriate analogy is height in basket ball. Consider that:
Countless other factors play in, including how hard and well the athlete trains (the two are far from the same…), what his physical characteristics in other areas are, how he fits in the team—and whether he is at all interested in basket ball.
It is possible to be an NBA player without being tall: Muggsy Boguesw played for 14 seasons at a mere 5 ft 3 in (1.60 m). (Numbers here and elsewhere copied from Wikipedia.)
Great height is no guarantee for anything: Robert Wadloww stood a full 8 ft 11.1 in (2.72 m)—but was hard-pressed to walk. Despite being the tallest man on historic record, theoretically able to dunk while keeping his heels solidly on the floor, he never played an NBA game.
Michael Jordanw, by many considered the greatest player of all times, was far shorter, at 6 ft 6 in (1.98 m).
Obviously, height in basket ball is just quackery…
No: As anyone who thinks the situation through, looks at more statistics about height (e.g. heree), considers the advantages under the basket, whatnot, soon realizes, great height is a major advantage and lack of height is corresponding disadvantage. This in particular when considering the statistics in light of how few men reach 7 feet compared to those who reach 6 feet.
In conclusion, I will look at two side-issues:
I have seen speculated that there is a certain “comfort interval” of roughly 30 IQ points within which people are sufficiently compatible to handle each other well: Someone with an IQ of 130 gets along well with people down to roughly 100, but has problems with those at 90; someone with an IQ of a 160 plays well down to 130, but has problems with someone at 120; etc. (Obviously, there is unlikely to be an abrupt change, but rather a gradual worsening.) This can go a long way to explain why many of the very highly intelligent have problems in life, including mental issues, problems in romance, surprisingly poor career developments, whatnot. (Speaking for myself: Yes, I find that when I am too far ahead of someone else, communication problems, differences in interests and world-view, etc., become disproportionally likely.)
Feynmanw is often taken as an example of an “ordinary” man who became a Nobel-prize winning physicist—his IQ being “only” 125.
Apart from 125 being more than one-and-a-half standard deviations above the mean, this number is highly likely to be misleading. Consider e.g. that anyone can have a bad day and score low, that he may not have taken the test seriously, or that he may have had his mind elsewhere, causing careless mistakes. Notably, I have spent a lot of time solving puzzles of various kinds (including questions from real IQ tests), and have found it to be important to know what level of difficulty the puzzle has: Different difficulties require different approaches and meta-reasoning—and a world-leading physicist could easily have over-estimated the difficulty of the questions.
Most notably, many IQ tests have a strong verbal component (the more so in the past) and there is reason to suspect that Feynman’s verbal IQ was far from stellar. At the same time, a physicist needs math ability, spatial thinking, and similar. Going by the books by him that I have read, I would only be mildly surprised to hear him going below 100 in verbal IQ—and shocked if he went above average + one standard deviation (i.e. roughly 115). He may then very well have had mathematical and visio-spatial IQs and a “g” on a genius level while still scoring just 125 overall.
Certainly, based on his books and accomplishments, Feynman was very, very far from average in raw intelligence—and a claimed IQ of 125 would point to a test that needed refinement or something having gone wrong. (Note that this would hold true even if IQ was a more flawed proxy of intelligence than I consider it to be: A man on his level should have no problem scoring higher on a well-made IQ test, be it in my world or in the world of Stephen Jay Gould.)