I went to a big sports school (football, hockey, basketball) so you could always spot the "jock" major. I happened to choose the current "jock" major at my school, and didn't realize it until I started my major classes and in every single one of them, the entire back row was filled with GIGANTIC guys. I'm talking all 6 feet and over 250 pounds. They were all always on time for class and they never skipped class! But they were rarely called on and rarely participated. Just quietly sat in the back.

I was in a few group projects with some of them and they all totally pulled their load in our groups. Most of them were quiet but they totally did their share of the work, and did it well.