In a book coming out next week called The Bonobo and the Atheist, primatologist Frans de Waal argues that morality is built into our species. Rather than coming to us top-down from God, or any other external source, morality for de Waal springs bottom-up from our emotions and our day-to-day social interactions, which themselves evolved from foundations in animal societies.

For 30 years, de Waal has authored books about apes and monkey that open our eyes to the bottom-up origins of our human behaviors, ranging from politics to empathy. In this, his 10th volume, he extends that perspective by writing, "It wasn't God who introduced us to morality; rather, it was the other way around. God was put into place to help us live the way we felt we ought to."

"The way we felt we ought to" has a long evolutionary history, so that de Waal's thesis depends crucially on numerous and convincing examples from our closest living relatives.

Read more at NPR.