There have been lots of threads on this:
http://talk.collegeconfidential.com/college-search-selection/758030-the-cult-of-ivy-league-personalities-p1.html
http://talk.collegeconfidential.com/college-search-selection/1359801-ivy-league-stereotypes-p1.html
http://talk.collegeconfidential.com/columbia-university/108356-ivy-league-stereotypes-p1.html