My son's father, uncle, paternal grandfather and grandmother all attended Harvard. (His grandfather did his graduate work there as well.) Do these five legacy connections (if you count grandpa twice!) prove a larger boost, either officially or unofficially, or is it more binary - "are you legacy or not"?
According to your list, only 1 out of the 5 legacy connections is viable. Harvard only considers a parent legacy status if they attend either Harvard College or Radcliffe College ( now part of Harvard).
As long as your son scores high on the Harvard admission score sheet for Academics, Intellectual Vitalty/Curiosity, ECs/Co-curriculars, Personal Character, Recommendations, and Athletics, he should get a boost from legacy status. Most typical admits (90%) have a composite score of 2+, 2, 2-.
If he's a 3 but a recruited athlete and a legacy, they may still consider him as well. Harvard uses their score sheets so that the admissions committee can compare apples to apples and ensure most admits meet minimum thresholds for grades, test scores, quality of their ECs, and recommendations. While a legacy applicant will get a boost for being a qualified applicant, it doesn't really help much if they are rated a 3,4, or 5 applicants. I'm sure they just defer them in the SCREA early rounds or waitlist them, so they are let down softy in the process.
It all depends on the college. For Harvard, I believe the answer is yes. Many private colleges are more dependent on the intergenerational connections and give a lot of weight to legacies. Most public schools ask, but it has little to no weight.
Also, most colleges consider "legacy" an undergraduate degree only.
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