People act and learn together for a rich mixture of reasons. The current story that most of us tell ourselves about how humans get things done is focused on the well-known flavors of self-interest, which make for great drama?survival, power, wealth, sex, glory. People also do things together for fun, for the love of a challenge, and because we sometimes enjoy working together to make something beneficial to everybody. If I had to reduce the essence of Homo sapiens to five words, "people do complicated things together" would do.
