Meritocratic sharing is based on collaboration in 3-year-olds.

The present study investigated young preschoolers' proportional allocation of rewards in 2 different work contexts. We presented 32 pairs of 3.5-year-old peers with a collaborative task to obtain rewards by pulling ropes. In order to establish differences in work input, 1 child's rope was not immediately accessible but had to be retrieved from the apparatus by means of a specific tool, while the other child had no such additional work to do. The result of the game was that 1 individual received 1 toy and the other received 3 toys. In the Deserving condition, the working child received the 3 toys (thus work and reward matched), whereas in the Undeserving condition, the other child received the 3 toys (he or she was overpaid, and the working child was underpaid). Another 32 dyads participated in a noncollaborative, parallel work task, again in a Deserving condition and an Undeserving condition. On average, children with 3 toys shared with their partner more in the Undeserving condition than in the Deserving condition after collaboration but not in a parallel work setup. These results suggest that young children take merit into account in distributing resources at a much younger age than previously believed and that peer collaboration is an especially facilitative context for children's attention to norms of fairness.