Children strategically conceal selfishness.

Can children exploit knowledge asymmetries to get away with selfishness? This question was addressed by testing 6- to 9-year-old children (N = 164; 81 girls) from the Northeastern United States in a modified Ultimatum Game. Children were assigned to the roles of proposers (who offered some proportion of an endowment) and responders (who could accept or reject offers). Both players in the Informed condition knew the endowment quantity in each trial. However, in the Uninformed condition, only proposers knew this information. In this condition, many proposers made "strategically selfish" offers that seemed fair based on the responders' incomplete knowledge but were actually highly selfish. These results indicate that even young children possess the ability to deceive others about their selfishness.