The Episcopal Cafe asks: More education = less religion? It points to a study of Canadian religiosity by Notre Dame economist Daniel Hagerman mentioned on Freakonomics.
But perhaps it’s not just higher education, but what one majors in. Rosalynde Welch concludes from another study that Humanities and Social Science majors are less likely to be religious after graduating than Science majors. She blames it on postmodernism, the encounter with pluralism, and methodological doubt. Of course, as one commenter on the Episcopal Cafe thread pointed out, members of the Episcopal Church are much more likely to have college and graduate education than the wider public, including the wider religious public.
Preaching Grace on the Square 
Rosalynde Welch’s article raises some interesting points but also makes some sweeping assumptions about both science and religion that are puzzling. Scientific inquiry and religious reflexion are two quite different universes of discourse. They are not trying to explain the same things, therefore insights generated in one sphere neither affirm or negate the “truths” of the other. As for the connection between the social sciences and humanities and religious conviction, the key problem is not that a greater awareness of the “relativism” of social structures or cultural complexity undermines religious faith. The central problem, as Marcus Borg shows in his latest book (“Speaking Christian”), is that what passes for religious faith in much of American Protestant Christianity is fundamentally misinformed. Biblical literalism cannot tolerate post-modern or any other serious historical criticism and that is the tradition that most students bring with them to college. If studying the humanities and social sciences frees them from the prison of “heaven and hell Christianity” so much the better.