Price Roe sent me this fascinating study on college students. It is a detailed survey of 263,710 students at 385 4-year colleges. That's comprehensive!
The American Freshman: National Norms for Fall 2005
By Sylvia Hurtado & John H. Pryor
(the 2006 study should come out next month)
they have been doing these studies since the mid-sixties and the results and trends are fascinating.