[roel_v]

People who have the stamina to finish a big project are already, by that measure alone, 'special'. Not that many people can slog on for so long working on something with an ill-defined goal and no clear steps to perform to get to that goal.

Apart from that I still don't think you're right. Take an extreme example: someone with a mental deficiency. I don't think it's a stretch to say that it's possible to find people in a home for the disabled who are, intellectually, in absolute terms incapable of getting a degree. With that as the 'lower' value, intelligence of others is a sliding scale all the way up to the geniuses of our world. Somewhere along this line, there is a cutoff point at which it becomes possible to get this degree. So, it must logically follow that there are a number of people who are not capable of getting it. One can debate on where that cutoff point is. I think it's over the median iq of all people, and that's a prudent estimate. That would mean that 50% of people (I'm not saying this is the cutoff point, I think it's higher, just to illustrate the point I'm making) are incapable, in absolute terms, of demonstrating the intellectual capacity that is needed to get this degree by today's standards.