Give and take: A microgenetic study of preschoolers' deceptive and prosocial behavior in relation to their socio-cognitive development.

Early on, young children begin to learn the social skills which will help them navigate through an increasingly complex social world. We explored how deceiving for personal gain potentially interacts with sharing the resulting resources and how they both relate to theory of mind (ToM) and inhibitory control in 3- to 5-year-old children (N = 92, 43 girls). Children played a hide-and-seek zero-sum game in which they could win stickers if they discovered how to deceive the experimenter. Then they were prompted to share their stickers in a dictator game paradigm. Using a microgenetic design, we tracked deceptive behavior across ten sessions and sharing behavior across five of these sessions, plus a follow-up session 15 months later. Children polarized into a group who never deceived across all sessions, and a group who constantly deceived above chance levels (around 85 % of the time). Sharing behavior was extremely low (under 6 % of stickers) across the sessions. At follow-up, deceptive behavior was above 80 %, while sharing remained at a low level (under 5 %). The novelty of our findings was that children who initially discovered how to deceive shared less than the children who didn't use this deceptive strategy. Nonetheless, this pattern was reversed at follow-up. Furthermore, ToM positively predicted deceptive behavior across all sessions and improved after the microgenetic sessions but wasn't related with deception at follow-up. Implications for enabling children to deploy the growing understanding of their worlds in a more prosocial way are discussed.