Playing Nice is Learned Early

Babies as young as 15 months old show sense of fairness and altruism

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Social cooperation and working together is the key to the success of the human race.

These innate, evolutionary characteristics appear to be learned a lot earlier than we thought. Infants seem to have a sense of fairness and exhibit altruistic behavior as early at 15 months of age.

"Human cooperation is learned from birth."

Jessica Sommerville, an associate professor of psychology at the University of Washington, led the first study to present evidence that a basic sense of fairness and altruism appears in infancy. Sommerville and her team measured 47 babies at 15 months old, an age chosen because it is when babies begin to show cooperative behaviors. The infants sat on their parents laps and watched two short videos that demonstrated sharing.

In one video, a bowl of crackers was distributed to other people - once with an equal allotment of crackers, but another time with unequal distribution of food. A second, similar video showed the same equal/unequal distribution with milk.

The babies spent more time looking at the times when one recipient received more food than another. Researchers call this the "violation of expectancy," and say that babies pay more attention when they are surprised. Sommerville said that the infants expected a fair distribution of food, and so were surprised and noticed when that didn't happen.

Her team also wanted to see if this sense of fairness was related to the babies' willingness to share, themselves. In the second part of the experiment, the infants were allowed to choose a toy that was then marked as their preferred toy. An experimenter, who the babies had not seen before, would ask to have a toy.

One-third of the babies shared their preferred toy, one-third shared a non-preferred toy, and the last third did not share at all, through either lack of motivation or nervousness of the stranger.

92 percent of the babies who shared their preferred toy had spent more time looking at the unequal distribution of food. In contrast, of the babies who only shared their non-preferred toy, 86 percent of them had paid more attention - possibly because they were more surprised - when the video showed a fair division of food. Researchers concluded that babies who were more sensitive to fair distribution of food were more likely to share themselves.

In the study, Sommerville wrote, "Human cooperation is a key driving force behind the evolutionary success of our hominin lineage. In contrast to past work suggesting that fairness and altruism may not emerge until early to mid-childhood, 15-month-old infants are sensitive to fairness and can engage in altruistic sharing."

The study has implications for nurturing altruism and cooperation. Findings were published in the journal PLoS ONE in October 2011.

Reviewed by: 
Review Date: 
October 10, 2011
Last Updated:
October 11, 2011