Résumé : We hypothesized that individual grading in group work, a widespread practice, hampers information sharing in cooperative problem solving. Experiment 1 showed that a condition in which members’ individual contribution was expected to be visible and graded, as in most graded work, led to less pooling of relevant, unshared information and more pooling of less-relevant, shared information than two control conditions where individual contribution was not graded, but either visible or not. Experiment 2 conceptually replicated this effect: Group members primed with grades pooled less of their unshared information, but more of their shared information, compared to group members primed with neutral concepts. Thus, grading can hinder cooperative work and impair information sharing in groups.