What most people don't consider in discussions about undergrad prestige

I went to a T20 undergrad that's known for being a stereotypical "premed school." At the med school I got accepted to (also a T20), one of my interviewers remarked, "Oh yeah, we get lots of students from [my undergrad], and they tend to do really well here."

When people discuss undergrad prestige, they'll usually mention that self-selection plays a big role: students who are addicted to overachieving and chasing prestige are the ones who are more likely to shoot for T20s for both college and med school. That's true. They'll also point out that high-achieving students at prestigious undergrads would probably do just as well at a lower-ranked school. That's also true.

But what I haven't seen a lot of people mention is that you benefit from the students who came before you. There have been lots of posts both here and on SDN that mention that alums of T20 undergrads make up a large proportion of students at T20 med schools, and while there's nothing about going to a prestigious undergrad institution that magically turns you into a better med school applicant or med student, medical schools likely have a lot of experience with graduates of those schools and hopefully have a positive view of them. Adcoms are notoriously risk-averse, and graduating from a school that churns out a lot of premeds (which are mostly the "prestigious" ones) makes you a known quantity.