New research suggests that babies as young as six months have already developed a sense of right and wrong.

The study from the Infant Cognition Center at Yale University theorizes that the notion of morality may be hard-wired into the brain at birth.

"A lot of philosophers and psychologists used to believe that babies start off knowing nothing, and in the domain of morality many people believe babies start off as little psychopaths – indifferent to the suffering of others, not knowing right from wrong," Yale University psychologist Paul Bloom told Canada AM Tuesday. "But in our own lab – and in other labs – we are finding a surprising rich understanding in morality, even in the youngest babies we could test."

In one experiment, babies between the ages of six months and one year watched an animated film in which a red ball tried to climb a hill, while a yellow square tries to help it up and a green triangle tries to push the ball down.

Scientists tested which shape the babies preferred by measuring how long they spent looking at a picture of each one. In 80 per cent of cases, babies chose the helpful shape over the unhelpful one

In another experiment, researchers devised "one-act morality plays" with puppets, with "good" animals and "bad" animals. The babies preferred the "good" animals when tested, going so far as to "reward" the good animal with a treat and take away a treat from the "bad" animal.

‘We've done some even more recent studies that show that babies have a rudimentary sense of justice, so if they see a different character punish a bad guy and reward a good guy, they like that character," Bloom said. "But if they see a character reward the bad guy and punish the good guy, they dislike that character.

"All of this speaks to an early moral sense of understanding of what is going on in that sort of relationship."

However, Bloom said parents should be cautious about the implications of his work.

"If you're happy with how you are interacting with your baby or child, that's terrific, our research tells you nothing new about how to do that," he said. "What it does tell us (is) I think parents can learn a lot and appreciate a lot by knowing just how smart and moral their babies are."