It also builds on the theme of community (which seems to be the hot topic lately). Kids work together in a community and make, learn and create through relationships. In this community students also build on and realize their own identity within the context of that community (of artists) and as an artist and a part of a larger community (of society).
I was thinking about Collaborative Art and how it fits into education and it occurred to me that collaborative art could be a very useful tool for those kids in your class that don't see themselves as creative people. Kids who think they can't draw or paint or aren't talented in visual arts would probably have a much easier time in creating collaborative art with their peers, perhaps sometimes without evening knowing that they are creating art and could be used as a very powerful tool to raise self esteem and confidence in the process of art making.