If reducing interest in religion is a sign of rationality, then social sciences rule! A new NBER paper compares college majors for their effect on student religiosity. Majoring in biological sciences, engineering, or vocational areas all increase religiosity about the same relative to not going to college. Majoring in education encourages religion even more, while majoring in physical science has about the same effect as no college. Majoring in humanities reduces religiosity relative to no college, and majoring in social science reduces it the most.