Preschoolers refer to direct and indirect evidence in their collaborative reasoning.

Collaborative reasoning requires partners to evaluate options and the evidence for or against each option. We investigated whether preschoolers can explain why one option is best (direct reasons) and why the other option is not (indirect reasons), looking at both problems that have a correct answer and those that require choosing the better option. In Study 1, both age groups produced direct reasons equally frequently in both problems. However, 5-year-olds produced indirect reasons more often than 3-year-olds, especially when there was a correct answer. In Study 2 with a nonverbal task with a correct answer, 3-year-olds produced indirect reasons more often than in Study 1, although 5-year-olds' indirect reasons were more efficiently stated. These results demonstrate that even 3-year-olds, and even nonverbally, can point out to a partner a fact that constitutes a reason for them to arrive at a correct joint decision.