I think our simple two factor model
Grades = ability + work ethic = IQ + W
is not too crazy. Note that once you fix the ability level (=SAT score) the remaining variance in GPA has about the same SD regardless of value of SAT score. . . . That suggests that we can think of IQ and W as largely uncorrelated random variables -- so there are smart lazy people, hard working dumb people, etc. I can't really prove the residual variance after IQ is controlled for is due to work ethic, but my experience in the classroom suggests that it is. . . . Beyond work ethic, some people are just more "effective" -- they can get themselves organized, are disciplined, can adapt to new challenges, are emotionally robust -- and this is also absorbed in the W factor above.
Now, in some fields there seems to be a minimum cognitive threshold. . . . Whether IQ has a large impact on life outcomes depends on how you ask the question. I do believe that certain professions are almost off-limits for people below a certain IQ threshold. But for most jobs (even engineer or doctor), this threshold is surprisingly low IF the person has a strong work ethic. . . . For typical jobs I think the correlation between success/income and IQ isn't very high. Other factors come into play, like work ethic, interpersonal skills, affect, charisma, luck, etc. This may even be true in many "elite" professions once you are talking about a population where everyone is above the minimum IQ threshold -- if returns to IQ above threshold are not that large then the other factors dominate and determine level of success. . . . [But] in science the returns to IQ above the . . . threshold (for getting a PhD) are pretty high. . . . Finally, when it comes to *individual* success I think most analysts significantly underestimate the role of pure blind luck (i.e., what remains when all other reasonable, roughly measurable variables have been accounted for; of course this averages out of any large population study).
A reader sums this up with an famous quote (of uncertain authenticity) on four types of men:
Field Marshall Erich von Manstein said that there were only 4 types of men. Smart hardworking men, who make excellent staff officers; smart lazy men who make the best general because they can make the right decision without all the information; stupid lazy men for whom uses could be found, and stupid hardworking men who must be avoided because of the problems they create.
Also notable was a post (quoting the New York Times) recounting the different academic backgrounds of right wing and left wing terrorists:
For their recent study, the two men collected records on 404 men who belonged to violent Islamist groups active over the past few decades (some in jail, some not). Had those groups reflected the working-age populations of their countries, engineers would have made up about 3.5 percent of the membership. Instead, nearly 20 percent of the militants had engineering degrees. When Gambetta and Hertog looked at only the militants whose education was known for certain to have gone beyond high school, close to half (44 percent) had trained in engineering. Among those with advanced degrees in the militants’ homelands, only 18 percent are engineers.
The two authors found the same high ratio of engineers in most of the 21 organizations they examined, including Jemaah Islamiya in Southeast Asia and Hamas and Islamic Jihad in the Middle East. Sorting the militants according to their 30 homelands showed the same pattern: engineers represented a fifth of all militants from every nation except one, and nearly half of those with advanced degrees. . . .
Gambetta and Hertog found engineers only in right-wing groups — the ones that claim to fight for the pious past of Islamic fundamentalists or the white-supremacy America of the Aryan Nations (founder: Richard Butler, engineer) or the minimal pre-modern U.S. government that Stack and Bedell extolled.
Among Communists, anarchists and other groups whose shining ideal lies in the future, the researchers found almost no engineers. Yet these organizations mastered the same technical skills as the right-wingers. Between 1970 and 1978, for instance, the Baader-Meinhof gang in Germany staged kidnappings, assassinations, bank robberies and bombings. Seventeen of its members had college or graduate degrees, mostly in law or the humanities. Not one studied engineering.
Presumably, radical moderates are mostly patent lawyers.