I think exposure at least offers you the opportunity of engagement with other perspectives. If your dad is racist but you go to school and make a black friend, that might change your perspective vs. if you lived in an area where mostly white people lived, and you had no practical experience to weigh against your dad's racist perspective. A lot of people stay siloed, especially after schooling ends. They work with the same people for decades, attend the same church, or otherwise cement their social circle for the most part, since there are fewer opportunities to meet people from different perspectives as an adult. This is in contrast to say undergrad, where half the kids in your dorm were from another country and everyone is looking to make friends as soon as possible, or public school where you make friends both rich and poor because you don't see class really when you are six years old, you just want to play tag.