The Ivies have between 4300 and 14,300 undergrads and are some of the most diverse colleges in the country. The admissions officers work very hard to avoid having a class of students who are too alike. There’s a popular saying on CC that colleges are looking for well-rounded classes, not necessarily well-rounded people.
You can come up with approximate stereotyped personalities for each Ivy, and people have been doing that on CC for over a decade now (see the links above), but it is a serious mistake to assume that all or even the majority of students at each Ivy share the same characteristics. The problem with generalizations like “artsy Ivy,” “hippie Ivy,” and “party Ivy” is that it can take minor differences between universities and blow them greatly out of proportion.
Be aware that a college that seems perfect on paper may feel very different in person, so visit the colleges of interest if you can. Brown in particular seems to trigger different responses in people, based on a thread a couple of years ago that discussed (dis)liking a college before vs. after a college visit.
Deresiewicz is a “former” professor because he was denied tenure at Yale and didn’t get job offers at any other colleges, not by choice. Now he makes a living taking potshots at the system he was working hard to get into.