Children's reasoning with peers in cooperative and competitive contexts.

We report two studies that demonstrate how five- and seven-year-olds adapt their production of arguments to either a cooperative or a competitive context. Two games elicited agreements from peer dyads about placing animals on either of two halves of a playing field owned by either child. Children had to produce arguments to justify these decisions. Played in a competitive context that encouraged placing animals on one's own half, children's arguments showed a bias that was the result of withholding known arguments. In a cooperative context, children produced not only more arguments, but also more 'two-sided' arguments. Also, seven-year-olds demonstrated a more frequent and strategic use of arguments that specifically refuted decisions that would favour their peers. The results suggest that cooperative contexts provide a more motivating context for children to produce arguments. Statement of contribution What is already known on this subject? Reasoning is a social skill that allows people to reach joint decisions. Preschoolers give reasons for their proposals in their peer conversations. By adolescence, children use sophisticated arguments (e.g., refutations and rebuttals). What the present study adds? Cooperation offers a more motivating context for children's argument production. Seven-year-olds are more strategic than five-year-olds in their reasoning with peers. Children's reasoning with others becomes more sophisticated after preschool years.