He isn't saying that at all. I think his main point is you are talking crap (though he articulated it much better than I have).

And Princeton (in undergrad) isn't "intellectually" elite, it is financially elite. I don't think you can derive anything about student "ambitiousness" just from how wealthy they are, and wealth is pretty much the only thing that separates Princeton undergrad student from a public college student.

Caveat: I'm assuming the study was done on undergrads, postgrad princeton is different beast.