How exactly does legacy work at top universities?

Ex:

I have an aunt who received her Ph.D. and Postdoc at Stanford. Will this give me much (if any) boost on my applications? Also, do they look up relatives to gauge their success?

It depends on the university. Some count only parents. Some count parents and grandparents. Some only count if the undergraduate degree was received at the school.

On the application, there is no box that says “Check here if you are legacy.” Each college is free to define legacy as it sees fit and how much (if any) of a bump it gives in the admissions process. In most cases, it will not cover a weakness in the application, though.

No, Stanford’s definition of legacy is:

https://www.stanforddaily.com/2009/12/02/legacies-a-fifth-of-the-class-of-2013/

No. Of course, if they are hugely successful and/or donate a ton of money, AO’s probably know that without having to look it up.

I have to believe that the legacy status at Stanford doesn’t give much of a boost. We have good friends whose son applied there a few years ago - both parents graduated from Stanford undergrad. Kid had a perfect SAT score, is an Eagle Scout, became a licensed pilot at a young age because it was a passion, did tons of community service, is a generally great kid, etc etc. He wasn’t even waitlisted. Just denied admission. He is now a senior at another great university and is thriving, so he found his fit and it all worked out.

“The percentage of alumni children admitted to Stanford is roughly three times the overall percentage of acceptance: somewhere in the mid to high teens.”

According to https://alumni.stanford.edu/get/page/magazine/article/?article_id=66225

At Stanford, legacy status ensures that the application gets a second reader. That’s it unless the family is a mega donor.

With that said, I would guess that most Stanford alums are affording their kids excellent opportunities to achieve. In other words, making them excellent applicants at Stanford and other schools.