Working With An "Out-Group"

Working with homeless children at Homeward Bound has been a very eye-opening experience for me. The children I work with defy any previous stereotypes I had of homeless people. If I saw them outside of Homeward Bound, I wouldn't even be able to tell they were homeless. Although it is hard to relate to them sometimes because I am not homeless, I can still relate to them because I am human. According to Kwame Anthony Appiah in Cosmopolitanism, "Once we have found enough to share, there is the further possibility that we will be able to enjoy discovering things we do not yet share" (97).
One of the things I have discovered from working with homeless children is that they are very similar to children who are not homeless. This is because they both share human characteristics of children. They even act similarly to the way I did when I was their age. Even though they may be strangers to me, "the warmth that comes from shared identity will...be available" (98). I believe that even if these homeless and non-homeless children met, they would still find that they share an identity: that of being children, and that of being human.
However, one could define the homeless as being the "out-group" of those who do have homes. But from the perspective of the homeless, they might consider the "out-group" to be those who have homes. In either case, they share identities with those within their own groups, such as family and friends. Perhaps they even gain strength from the fact that they share similar characteristics with those in their in-group, whether it is having a home or not having a home.
Could you define the group you are working with as an "out-group?" Is it necessarily a bad thing to be part of this "out-group?" What could be some possible benefits from belonging to an "out-group?"