i've done a real iq test which consisted of a few long sessions with a psychologist who gave me lots of tasks to do, like identifying patterns in pictures, determining which shape will come next, memorizing geometric shapes, logic stuff and many more i can't remember. i think the iq test measures a very specific type of 'smart', which is rarer in society, that people who have a talent for math and physics often have, like being creative in a logical/mathematical way, thinking 'outside of the box' and recognizing patterns. when studying physics and math, taking notes and memorizing the equations is simply not enough to truly understand the material. you have to have that certain talent to some level to do well in these fields and that might explain why they are a little more 'selective' i guess. however, when studying a subject you need a lot more than 'raw' talent to succeed and there are other abilities, just as important, that an iq test doesn't measure. plus, what does op mean by 'high iq'? high compared to what? the average? high school students? college students? other science majors? completing a degree is one thing, but how many of those will have the grades and ability to continue on to grad school? phd? or even become professors? that's just my opinion here