toddler
Although we often think of young children as rather selfish, research has shown that babies and toddlers have a surprisingly strong sense of what is fair. At one year old, kids already expect resources to be divided fairly and for people to be helpful towards others. By two, they themselves tend to distribute resources equally, and would rather play with a fair adult than an unfair one.

But at what point do young kids actually intervene when they see someone else acting fairly or unfairly? According to a series of studies in Cognition, before they're even one and a half years old children will reward someone for being fair — though they don't yet punish unfair behaviour.

The team, led by Talee Ziv from the University of Washington, first trained a group of 16-month-olds to use a touch screen to produce audio clips. Touching one side of the screen resulted in negative feedback (e.g. "She was bad") while touching the other side produced positive feedback (e.g. "She was good").

The kids then saw four video clips, each showing a woman distributing crackers or Lego blocks to two other people. In two of the clips, the "distributor" divided up the resources fairly, but in the other two she gave one person more than the other (a different actor played the role of distributor in each of the four clips). After watching these videos, the toddlers were again shown the faces of the four distributors, and after seeing each one had 60 seconds to touch the screen as many times as they wanted.

The team found that when the children saw the fair distributors, they touched the side of the screen that gave positive feedback significantly more often than the side that gave negative feedback. But when they saw the unfair distributors, there was no difference in the number of times they touched each side of the screen.

These results suggested that the children were "rewarding" the fair actors with positive feedback. But it wasn't clear that they really grasped the idea that the audio clips would be rewarding to the actor. So to ensure that the kids understood that their actions produced a clear reward or punishment, in a later study the researchers tweaked the methods so that touching one side of the screen produced a video of someone giving the actor a cookie, while touching the other side produced a video of someone taking a cookie away.

Once again, the children rewarded the fair distributors by pressing the "give cookie" side of the screen more often than the "take cookie away" side. But they pressed each side of the screen equally when the distributors had acted unfairly.

Overall, the results suggest that toddlers reward those who are acting fairly, adding to the evidence that very young children have a strong sense of what is "right" or normative. But, interestingly, these kids don't seem to punish those who have been unfair (in fact, the researchers suggest that the children instead tended to avoid making responses towards unfair distributors, as they touched the screen fewer times overall after seeing those who acted unfairly).

Further research is needed to understand why toddlers don't punish unfair actors. They might not see the actions as bad enough to warrant any kind of punishment, the team suggests, or could believe that punishment is only done by people in positions of authority. Or maybe the concept of punishment develops later than that of reward. Either way, the team concludes, the results imply that punishment is not simply the flip side of reward, but that the two are unique processes that may develop differently in children.

Toddlers' interventions toward fair and unfair individuals