Teams often fail to reach their potential because each member’s need to feel accepted prevents him or her from offering their unique perspective or information to the team. Drawing on self-affirmation theory, we propose that social worth affirmation – which we define as the process by which an individual’s unique contributions are affirmed by social relationships – can prepare individuals to contribute to team performance more effectively. We theorize that affirming team members’ social worth spills over to the new team context, thereby decreasing their social concerns about being accepted by other members. This, in turn, leads to better information exchange and performance in teams. In a first field experiment, we found that teams in which members experienced social worth affirmation prior to team formation performed better on a problem-solving task (compared to teams without social worth affirmation). In a second experiment, conducted using task-oriented teams in the U.S. military, we tested a full model that social worth affirmation influences information exchange and team performance by reducing members’ concerns about social acceptance. In the third experiment using virtual teams, we find that social worth affirmation improves teams’ ability to exchange information by sharing unique information cues.