<p>It might be a large percentage for this particular year, but I imagine if you average over the past 20 years or something Caltech won’t seem different from any other school.</p>
<p>From what I heard about the grad student, they were pretty upbeat and positive, and nobody in their lab had a clue anything was wrong. The only possible cause I heard was their advisor was a bit strict/harsh/demanding, but that would really be a shortcoming of that particular professor and not the institution as a whole.</p>