Human social behavior is wildly influenced by major uncertainties about our own nature, and our own "place" in the cosmos. That is, we seek out people, experiences, and social institutions to learn about, develop, edit, distill, and confirm/reject answers to fundamental questions of existence. And, it is with this information that many social actions are influentially guided. That said, a little wisdom from philosophy on these matters can be very illuminating on why The Social Brain acts as it does.
To know or not to know?
"Blessed are the forgetful: for they get the better even of their blunders."
What are the defining characteristics of one's personality or identity?
"Character is determined more by the lack of certain experiences than by those one has had."
How can we maximize pleasure, and minimize pain?
"We must not study ourselves while having an experience."
Should we try to get back to the "good old days," "live in the now," or "plan for the future"?
"Existence really is an imperfect tense that never becomes a present."
What is the purpose and/or meaning of life?
"Art is the proper task of life."
What is next, or should be next, for humankind?
"Man is something that ought to be overcome."
Source: Friedrich Nietzsche
(Note: There certainly will be more to come on this theme as many of the most thorny questions about the social animal have already been thoroughly examined, for millenia, by great philosophers, or as I sometimes like to call them "pre-scientists.")