Image credit: Simon Wheeler Ltd/Getty Image

New research is proving that humans are naturally pretty nice  with "pro-social tendencies"  and not as "nasty" as previously thought, according to a top primate-behavior expert.

Frans de Waal, a biologist at Emory University in Atlanta, told a meeting of the American Association for the Advancement of Science that new research was helping to challenge earlier beliefs - popular until more than a decade ago - that humans were competitive, aggressive and plain-old mean, according to The Discovery Channel.

He showed videos from laboratories of a monkey displaying emotional distress after being denied a treat that another had received as well as a rat turning down a snack to help another rat escape from a trap.

De Waal, the author of "The Age of Empathy: Nature's Lessons for a Kinder Society," said the new research revealed that animals were naturally capable of "reciprocity, fairness, empathy and consolation."

He told the audience in Vancouver, British Columbia, on Monday that human children and most higher animals, such as primates and elephants, are "moral" because they need to cooperate with each other to reproduce and pass on their genes, The Discovery Channel reported.

But he told reporters that animals empathized with those within their "in group" but that courtesy was not so easily extended in the human world.