The November 2011 edition of The Atlantic presents E. O. Wilson's "Theory of Everything." Wilson's theory takes into account the "eusocial" status of human animals, something that we share with ants and bees, but very few other species. Eusocial animals build complex societies wherein "individuals specialize in various activities and sometimes act altruistically." Wilson has taken the position that eusociality is not the result of close genetic similarity (the explanation offered by "kin selection"). Rather, he is a strong advocate of "group selection." By the way, E. O. Wilson is no relation to another Wilson who has strongly advocated group selection, David Sloan Wilson (and see here). Here's how E. O. Wilson presents group selection, according to a passage from The Atlantic:

In his new book, Wilson posits that two rival forces drive human behavior: group selection and what he calls “individual selection”—competition at the level of the individual to pass along one’s genes—with both operating simultaneously. “Group selection,” he said, “brings about virtue, and—this is an oversimplification, but—individual selection, which is competing with it, creates sin. That, in a nutshell, is an explanation of the human condition. “Our quarrelsomeness, our intense concentration on groups and on rivalries, down to the last junior-soccer-league game, the whole thing falls into place, in my opinion. Theories of kin selection didn’t do the job at all, but now I think we are close to making sense out of what human beings do and why they can’t settle down.” By settling down, Wilson said, he meant establishing a lasting peace with each other and learning to live in a sustainable balance with the environment. If Wilson’s new paradigm holds up—“and it will,” he insisted in an e-mail exchange several weeks after visiting Gorongosa—its impact on the social sciences could be as great as its importance for biology, advancing human self-understanding in ways typically associated with the great philosophers he criticized. “Within groups, the selfish are more likely to succeed,” Wilson told me in a telephone conversation. “But in competition between groups, groups of altruists are more likely to succeed. In addition, it is clear that groups of humans proselytize other groups and accept them as allies, and that that tendency is much favored by group selection.” Taking in newcomers and forming alliances had become a fundamental human trait, he added, because “it is a good way to win.”