There are specific elite colleges that many well qualified applicants desire to get admission to, of which, the main problem for gaining admission for those potential students, is the fact that the overall number of applicants, typically, far exceeds the availability of student slots. This thus indicates, that a significant amount of those potential students will be denied entry to their college of choice, which would probably be acceptable, if the process in the selection of which students who were admitted, was transparent, based on objective merit, and always consistent in the scoring and evaluation of who gets in and who does not.
Not too surprisingly, despite all the talk about fairness, objectivity, meritocracy, having the right stuff, specific standards, as well as other criteria, the selection of those students so admitted to a given elite college has a lot more to do with the preferences of those so making those decisions, as well as also the constraints and objectives that they are subject to by the powers-to-be, then impartiality and openness. Further to the point, one of the things that elite colleges do not desire to openly discuss is the fact that there is often a backdoor to admission to their college, which is done through specific legacy preferences.
A legacy preference is basically providing to those potential applicants that have had relatives, as in usually their mother and/or father, that have gone to that college, receiving a corresponding boost to their perceived qualification so as to better accommodate their admission to that college, as opposed to this not being a factor, that is even looked at. No doubt, there are families, that want their progeny to go to the same higher educational institution that they went to, not only because it continues a given legacy, but also because they perceive that college’s value, trust in the value of that institution, and finally because on some level, they believe that their progeny is entitled to it.
As for why any given elite college, would care about a given legacy, it almost goes without saying, that those families that believe in that institution, are probably going to be more generous in their donations to such, as well as typically being more engaged with that college; and finally those colleges recognize the value of legacy students going to their institution as being more conducive for those students in making the right connections, which thereby serves to setup a positive feedback loop for everyone.
After all, elite colleges are hardly stupid, for they know that part of what gets a particular person ahead, or a particular institution for that matter, is having the right networking, which allows such to meet and to know the right people from the right institutions, leading to the implicit understanding of the valued interplay between education and the subsequent successful entry of that student into a meaningful career. So, what we do find, is that legacy preferences are the workaround for colleges from being limited to evaluations so graded by strict meritocracy or fairness, to thereby permit those students that already have a significant leg up to sustain from one generation to the next, all the inherent advantages of being in the right place at the right time.