Witness the way frats function at Columbia - the doors seem most often closed to non-brothers and rarely do you have the whole campus "circuiting" around different parties, frats, off campus parties, etc the way you do at other Ivies.
Witness Columbia 5 year reunions - a 20% attendance is a good year. Dartmouth and Princeton bring in closer to 80% - Brown and Yale around 60%. That's a substantial difference which I think is truly indicative of the differences in culture.
^I would be surprised if reliable data exists to support that assertion. I would be astonished if reliable data exists to support the assertion that the percentage of Harvard, Princeton and Chicago students who both seek and obtain investment banking jobs exceeds the percentage at Columbia.