Interesting question–I have always wondered this too, if schools use it as part of yield assessment (ie family connections at another school makes matriculation at any non-connected school less likely). The question of where each parent went to college was on every college app last year–or at least most–as well as questions on where graduate degrees were obtained. I actually was remembering it as a Common App question? But maybe it was individual schools that questioned it. I was just the last-minute proof-reader of each app so I still do not fully understand how the common app works. And some asked about siblings too! So for D23 I would certainly hate it if schools assume she wants to go where her parents did and where her sister currently is! Maybe if they have kids themselves they will understand that a current sibling can very well make them LESS likely to want to go!!