In “Born to Be Good,” Dacher Keltner describes the work he and others are doing on the mechanisms of empathy and connection, involving things like smiles, blushes, laughter and touch. When friends laugh together, their laughs start out as separate vocalizations, but they merge and become intertwined sounds. It now seems as though laughter evolved millions of years ago, long before vowels and consonants, as a mechanism to build cooperation. It is one of the many tools in our inborn toolbox of collaboration.

In one essay, Keltner cites the work of the Emory University neuroscientists James Rilling and Gregory Berns. They found that the act of helping another person triggers activity in the caudate nucleus and anterior cingulate cortex regions of the brain, the parts involved in pleasure and reward. That is, serving others may produce the same sort of pleasure as gratifying a personal desire.

In his book, “The Righteous Mind,” to be published early next year, Jonathan Haidt joins Edward O. Wilson, David Sloan Wilson, and others who argue that natural selection takes place not only when individuals compete with other individuals, but also when groups compete with other groups. Both competitions are examples of the survival of the fittest, but when groups compete, it’s the cohesive, cooperative, internally altruistic groups that win and pass on their genes. The idea of “group selection” was heresy a few years ago, but there is momentum behind it now.

Human beings, Haidt argues, are “the giraffes of altruism.” Just as giraffes got long necks to help them survive, humans developed moral minds that help them and their groups succeed. Humans build moral communities out of shared norms, habits, emotions and gods, and then will fight and even sometimes die to defend their communities.

Different interpretations of evolution produce different ways of analyzing the world. The selfish-competitor model fostered the utility-maximizing model that is so prevalent in the social sciences, particularly economics. The new, more cooperative view will complicate all that.

But the big upshot is this: For decades, people tried to devise a rigorous “scientific” system to analyze behavior that would be divorced from morality. But if cooperation permeates our nature, then so does morality, and there is no escaping ethics, emotion and religion in our quest to understand who we are and how we got this way.