I have to say that this is actually pretty wrong, at least for US undergraduate admissions at many “elite” schools (In a former life, I was a faculty member at an “elite” school). As far as I know, the undergraduate admissions committees at HYPS have no faculty members on them, and it’s somewhat rare for them to seek opinions on an application from the faculty.
Of course, I’m sure there are exceptions to this at schools like Caltech, LACs, professional majors like theater, dance, or at Oxbridge in the UK. And I honestly don’t know if engineering faculty members sit on the admissions committee at universities like Northwestern and Cornell that have separate admissions committees for their engineering schools. However, I tend to doubt that faculty members would be spending their time reading applications even at these engineering schools. (I actually think admissions committees do a reasonably good job, but it’s always been funny to me that the admissions officers at schools like HYPSM who pass judgement on candidates tend not to be people who themselves could have been admitted as undergraduates.)
At the Ph.D. level at HYPSM, it’s completely different. There, faculty in the individual departments make most of the decisions. The central admissions office at the graduate school does a final review, but for the most part individual departments decide.
If faculty members were more involved in undergraduate admissions at “elite” schools, they’d probably vote to increase the percentage of academic admits … not that they don’t enjoy teaching the average undergraduate, but there’s something very energizing about mentoring a young brilliant mind and helping them discover what’s exciting about your field of interest. Frankly, even at a school like Harvard there just aren’t that many of these students.
In my opinion, this is related to one of the biggest misunderstandings about how admissions work at “elite” schools. Even at schools like Harvard where test scores are really high, only about 10-20% of the students are “academic” admits. When Harvard talks about someone being admitted for their academics, they mean that the student seems to have some potential to possibly make a world-class intellectual contribution sometime in their life. It has nothing to do with SAT or AP scores (though of course kids with this kind of potential tend to have really high grades and scores without even really needing to try very hard). There’s no SAT score in the world that by itself is going to put someone in Harvard’s academic admit bucket. The problem of course is that it is really hard to identify real intellectual potential in 17 year olds who come from all sorts of different backgrounds.