Infants have more social savvy than usually given credit for. Credit: Punchstock

You might scoff at doting parents who proudly tell you that their youngster, even though still in diapers, takes an instant liking to kind-hearted people and shows disdain for less savoury characters. But a new experiment shows that such claims could be more than parental pride. Babies, it seems, have a lot more social savvy than we credit them with.

Research led by Kiley Hamlin, a graduate student at Yale University in New Haven, Connecticut, shows that babies less than a year old can judge the niceness or nastiness of others, even when watching events that don't directly affect them. The researchers made the discovery using nothing more high-tech than a simple puppet show.

After watching the show, the babies, aged either six months or ten months, instinctively preferred 'nice' characters over less helpful ones. This kind of skill may be useful in helping them learn the right values as their social awareness develops later in childhood.

"We knew that babies were socially skilled, but we weren't aware that they were so skilled that they could track people by their behavioural tendencies; how they might treat someone else," says Hamlin.

Evil puppets

Going up? Kids tend to approach the puppet that helped its mate up the hill. Credit: Nature

Hamlin and her colleagues showed the babies a puppet show in which the central character, a brightly coloured round wooden block complete with googly eyes, tried in vain to scale a steep hill. The puppet was then either given a friendly shove up the hill by a 'good Samaritan' puppet, or thwarted by an evil puppet who pushed the climber back down.

After the show, the babies were encouraged to reach out for either the helper or the hinderer puppet. Almost all favoured the helper, Hamlin and her colleagues report in this week's Nature1.

"This suggests to us that at least they're able to tell them apart, and also that they have some tendency towards the positive helper," Hamlin says. "We were shocked by the strength of the responses. We thought infants would be sensitive to the behaviour of others, but didn't anticipate the extent of this."

What's more, the effect was not so marked when the puppets' googly eyes were removed, showing that the babies identify with the puppets as characters and make their choice on the basis of the characters' actions, even though the babies were not personally affected by the show's events.

In a second experiment, the babies were again shown the puppet show, and then saw the climber subsequently appear to 'make friends' with either helper or hinderer. The older babies spent longer looking at it when the climber approached the hinderer, suggesting that they found this event more surprising. The result shows that the older babies, although not the younger ones, can draw fairly sophisticated conclusions about the social attitudes and motives of others, say the researchers.

Parental pride

"You get a lot of parents saying their babies have these reactions to different kinds of people," says Hamlin. "It's been said anecdotally but never tested experimentally before."

The fact that babies can make choices like this at such an early age suggests that the ability to choose between nice and nasty may even be innate, Hamlin says. This may even form the bedrock of a child's social development, she suggests ? by favouring helpful over unhelpful people, a growing child may sow the seeds for strong social ties with others in later life.

"Just by spending more time with positive people, they might get a different set of learning inputs than if they spent time with negative people, and over time you can see that could have a real influence on their development," Hamlin says.