I think that Bostonian meant that getting a degree in a traditional college subject such as English, history, economics, the sciences, etc., requires an above-average IQ (at a minimum, IMO).
I don't think that that's accurate. It's certainly true that above-average intelligence helps greatly. I'm certainly willing to consider that some courses of study (I think you mentioned tensor calculus once or twice in the past) would require higher than normal working memory to do well. What I'm not seeing is the evidence that high IQ is required just to graduate from a range of even the traditional fields. I think a properly motivated, properly taught person of even average intelligence can do quite a bit of abstract and critical thinking; it's just that few public schools in the U.S., at least, teach these skills, leaving many to rely on their native smarts alone. Abstract logic, critical thinking, creativity, etc. are not magical, and can be taught despite some people having more of a bent for them (I know you know this, and I'm not trying to be pedantic).
For example, it's obvious that someone can become hobbled in math ("innumerate") by bad teaching, which often starts quite early on. Replace that with proper instruction and you might get a different picture. What we need is twin studies, where one twin is brought up in Singapore and one in the backwoods of the U.S.
We could probably start drawing all sorts of boundaries-- one really needs a certain working memory and processing speed to cope with Harvard Law, for instance-- but I just don't see a hard lower limit on intelligence for going to college in general. Of course some colleges and majors are tougher, but I'm sure a great many people with average IQ (or average intelligence) manage to graduate from
some college, even in your traditional core fields.
I see the bar for entry to college as pretty low, and well within the capabilities of most people if they were well-taught. When people drop out, I think it's less likely to be because they don't have raw biological thinking horsepower than a host of other reasons, including finances, lack of interest, emotional reasons, poor study habits due to lack of training, and lack of a decent program running on that brain hardware (poor critical thinking skills, etc.).
(I also think that one could permanently improve the intelligence of anyone with normal beginning intelligence through training, and likely more than the ~5-point bump that's been discussed previously as evidenced by the Colorado Adoption Project and other studies, but we can discuss that a different day and in a different thread.)
I'm certainly no expert on anything intelligence-related, but maybe what I'm thinking is that a great deal of intelligence can be crystallized, including the sorts that help people do well in college and succeed at a job. People can be taught how to think and how to learn; higher-aptitude people just do a better job of filling in the blanks for themselves than average people.
