Do infants expect fairness in distribution?

As adults, we may be concerned about income inequality, or an unequal distribution of wealth. Often, the distribution of wealth can appear to be unfair. But from what age can infants begin to understand fairness of

distribution?

In a study designed by Jessica Sommerville, 12 month-olds and 15 month-olds were tested to see how long they would spend watching a scene where resources were distributed equally (the equal distribution condition), compared to a scene where resources were distributed unequally (the unequal distribution condition).

In both conditions, the scene presented involved one distributor and two receivers, all seated together around a table. The distributer had four crackers to distribute to the two receivers. In the equal distribution condition, two crackers were distributed to each receiver. In the unequal distribution condition, three crackers were distributed to one receiver, and one cracker was given to the other receiver. 

Results found that 12 month-old infants spent the same amount of time viewing the two scenes, whereas 15 month-olds spent significantly longer time viewing the scene where resources were distributed unequally. When infants view one scene for a longer duration than another, it indicates that something unexpected occurred in that scene. Presumably, 15 month-old infants had expected the experimenter to distribute the crackers equally, and were surprised when this was not the case.

The results of the experiment indicate that 15 month-olds were concerned with unequal distribution of resources, while 12 month-olds were generally not. As adults in society, we tend to hold that all else being equal, a fair distribution of resources would be an equal distribution of resources. It seems that 15 month-old infants would agree, but 12 month-old infants are not that far off. It appears that in the short period of 3 months between those two ages, infants undergo a rapid transformation in their ability to understand fairness. This study shows that not only can humans understand fairness from an incredibly young age, but also that this ability develops rapidly in the first year of life.