Stress. I do not mean to imply that all cohesive groups necessarily suffer from groupthink. All in-groups may have a mild tendency toward groupthink, displaying one or another of the symptoms from time to time, but it need not be so dominant as to influence the quality of the group's final decision. Neither do I mean to imply that there is anything necessarily inefficient or harmful about group decisions in general. On the contrary, a group whose members have properly defined roles, with traditions concerning the procedures to follow in pursuing a critical inquiry, probably is capable of making better decisions than any individual member working alone.