London: Believe it or not, babies as young as 15 months have a basic sense of what is fair, says a new study.

In the study, researchers at University of Washington found that children could notice the difference between the equal and unequal distribution of food or drink and reacted with surprise to perceived unfairness.

That altruistic awareness and concern for others was also linked to their willingness to share a toy.

Professor Jessica Sommerville, who led the study, was quoted as saying, "Our findings show that these norms of fairness and altruism are more rapidly acquired than we thought."

Babies watched videos of crackers and milk being shared out. Prof Sommerville said, "The infants expected an equal and fair distribution, and they were surprised to see one person given more crackers or milk than the other."

The babies were also given two toys from which to choose in the study, a third of them were ready to share their  favourite toy, another third shared their non-preferred one, but the final third did not share.

Professor Sommerville said, "Babies who were more sensitive to the fair distribution of food were also more likely to share their preferred toy."

The results, published in the 'PLoS ONE' journal, showed that even early in life there are individual differences in altruism.