I think you're correct that experience will differ substantially by context. I think your particular generalizations might hold enough to show up in a regression but there's enough other stuff going on (and noise) that they won't be tremendously predictive in individual cases.

I was a STEM major, did well at a reasonable school, and the only time I felt like I had way the hell more homework than I could get through was at a community college when I signed up for a Literature course and a Political Science course the same summer.