Recent experiments suggest that reciprocity of this kind is neither natural nor intuitive: Young children showed almost no awareness that they should repay favours to those who helped them in the past.
Helping those who help you
The principle of direct reciprocity – paying back those who have helped you in the past – is so central to everyday life that it’s often imbued with moral status. In many societies, failure to return a favor can be considered a great offence.
Beyond the personal level, researchers have argued that direct reciprocity can explain both the success of communities and the evolution of co-operation more generally. We reasoned that if reciprocity is indeed something that evolved as a foundation of the way human beings interact with others, it should come naturally to young children.
To test this hypothesis, we designed a simple computer game for 4- to 8-year-olds. Children interacted with four avatars that we told them were other children playing the game. In one version, all of the “other children” received a sticker, leaving the child without any. But then one of the players gave their sticker to the child.
We found this same effect several times in other groups of children, again finding no evidence that they respect the principle of “you scratch my back, and I’ll scratch yours”.
Does this mean children never show direct reciprocity? Not exactly. In fact, they did, just in the form of grudges rather than gratitude.
Paying back with a punishment
Direct reciprocity actually comes in two flavors. In addition to the positive form of returning benefits – showing gratitude – there is a negative form of returning injuries – holding grudges. This negative form is also ensconced in proverbs, such as “an eye for an eye”.
We tested the negative form of direct reciprocity with a different group of children, who played a “stealing” version of the task.
Children started with a sticker which was then stolen by one of the four computer players. Later the other players had stickers and the child had the opportunity to take from one of them. Now children retaliated, often with relish, snatching a sticker from the thief in order to even the score.
Why were children of the same age eager to retaliate but unconcerned with returning a favor? Here too, memory errors or biases could not account for the phenomenon: Children were just as good at remembering the nice person as the mean person, but they only reciprocated in the case of negative behavior.
An expectation that must be learned
Young children may not respond to obligation, but researchers know they try to abide by social expectations. We wondered if children were simply unaware of the norm of returning favors. Maybe it just doesn’t occur to them to reciprocate the benefits they received.
So, we asked them. We used the same game as before and children still received a sticker, but this time, we just asked “Whom should you give to?” In this case, kids in the oldest age group we looked at, 7- and 8-year-olds, did systematically pick the person who had given a sticker to them. Younger children chose the potential beneficiary at random; it appeared that they simply didn’t know the rule.
Our results suggested that young children must learn the principle of direct reciprocity in order to apply it.
So the upshot isn’t so grim after all: grudges may come more naturally than gratitude, but gratitude is readily learned. Perhaps, then, the reason why there are so many fables like “Androcles and the Lion” about reciprocity isn’t because the behavior comes so naturally. Instead, we need the fables precisely because it doesn’t.