But human children -- and most higher animals -- are "moral" in a scientific sense, because they need to cooperate with each other to reproduce and pass on their genes, he said.
Research has disproved the view, dominant since the 19th century, typical of biologist Thomas Henry Huxley's argument that morality is absent in nature and something created by humans, said de Waal.
And common assumptions that the harsh view was promoted by Charles Darwin, the so-called father of evolution, are also wrong, he said.
"Darwin was much smarter than most of his followers," said de Waal, quoting from Darwin's "The Descent of Man" that animals that developed "well-marked social instincts would inevitably acquire a moral sense or conscience."
De Waal showed the audience videos from laboratories revealing the dramatic emotional distress of a monkey denied a treat that another monkey received; and of a rat giving up chocolate in order to help another rat escape from a trap.
Such research shows that animals naturally have pro-social tendencies for "reciprocity, fairness, empathy and consolation," said de Waal, a Dutch biologist at Emory University in Atlanta, Georgia.