My group was new, lacking much in the way of research funds. Therefore, we taught for support (Chemistry): lab proctor, recitation leader. Somebody had to wrangle those 1000 people taking 1st-year chemistry. Pre-med, pre-vet, pre-dental, biology and a rare chemistry major or two. In return, the department covered my living expenses. This was in ancient times, but I figure similar mechanisms exist today because the student base seems to be quite similar.