Preschoolers' understanding of others' desires: fulfilling mine enhances my understanding of yours.

We developed a gift-giving task requiring children to identify their mother's desire, when her desire differed from theirs. We found a developmental change: 3- and 4-year-olds performed more poorly than 5-year-olds (Experiment 1). A modified version of this task (Experiment 2) revealed that 3-, 4-, and 5-year-olds whose desires had been fulfilled chose an appropriate gift for their mothers significantly more often than children whose desires were unfulfilled. Children who merely anticipated desire fulfillment also outperformed children whose desires were unfulfilled. Analysis of children's verbal explanations provides converging evidence that desire fulfillment enhanced children's tendency to adopt the perspective of their mother and justify their choices by referencing her desires. Discussion focuses on why desire fulfillment enhances children's ability to consider the desires of others.