Each of the twelve jury members fulfilled a role at some point within the movie. They fulfilled task roles, maintenance roles, and self-centered roles. They had to learn to work together despite the roles they played to come to a unanimous decision.
The Forman (Juror #1) fulfilled one group maintenance role (tension reliever) and two group task roles (procedural technician and initiator). As a tension reliever, the Forman told Cobb to calm down when Cobb started on his rant. He often tried to relieve tension in situations with conflict. As a procedural technician, Forman emphasized teamwork by asking the group to vote a couple of times in a couple different ways, vocal ballots and silent ballots. This helped the group stay on track. He also ran errands for the group, like retrieving the knife and the apartment blueprint. As an initiator, the Forman initiated the discussions after the jurors would break in the beginning of the movie.
Whimpy (juror #2) fulfilled a group maintenance role as a supporter. Once Whimpy changed his vote to not guilty, he supported Fonda’s ideas. When Fonda was conversing with Cobb about the glasses, Whimpy supported Fonda’s point of view and told Cobb, “You can’t send someone off to die on evidence like that!” Lee J. Cobb (juror #3) played three individual roles (blocker, dominator, and confessor) and one group task role (opinion giver). Cobb played the role of