Groupthink is a theory dedicated to understanding the decision-making process in small groups. Janis believes that groups frequently make decisions with profound consequences, and although he focused his efforts on foreign policy groups, the application of Groupthink terminology resonates to many other decision-making groups.

The theory of Groupthink is a heuristic undertaking; the theory and many of its elements have been employed in a number of studies and have enjoyed the attention of many communication and social psychology scholars (for example, Cline, 1990; Courtright, 1978; Hensley & Griffin, 1986; Pavitt & Johnson, 2002; Turner & Pratkanis, 1998). The theory has generated a number of different assumptions about group behavior, and Groupthink remains an important part of the literature on group decision making. Ramon Aldag and Sally Riggs Fuller (1998), for instance, state that "[groupthink] has stimulated research on group dysfunctions and encouraged viewing outcomes in problem-solving terms; shown how decision processes may be relevant to a wide range of situations; provided links to other literatures, such as stress and vigilance; and identified potentially important variables in group problem solving" (p. 57).

The scope of the theory is relatively narrow, and Janis (1972) cautions readers to keep in mind that the hypotheses he advances require more rigorous assessment before they can be fully accepted. Janis also limits his discussion to decision-making groups who are in crisis periods; he does not readily apply all of his thinking to all types of groups.

Critics, nonetheless, have been vocal in their assessments of Janis's theory. Jeanne Longley and Dean Pruitt (1980), for instance, criticize the validity of the theory. They argue that half of the symptoms of groupthink are not associated with concurrence seeking—a key feature of the theory. They charge: "A theory should be a logical progression of ideas, not a grab-bag of phenomena that were correlated with each other in a sample of six cases" (p. 80). Further, they note that Janis includes self-esteem in discussions about groupthink, yet he fails to mention self-esteem in his theory. In later writings of the theory, however, Janis (1982) addresses self-esteem as an antecedent to groupthink.

Concurrence seeking also concerns Alexander George (1993). He surmises that Janis may have unintentionally caused some to inappropriately extend his theory into other domains because Janis "did not succeed in impressing on his readers that concurrence seeking emerged under conditions of severe decisional stress" (p. 37). George remains concerned that there are no empirically observable signs of concurrence seeking in group decision making. He also wonders whether the symptoms are exclusive to concurrence seeking or whether the symptoms can occur without it.

Paul 't Hart (1991) critically observes that Janis first chose examples of foreign policy disasters and then applied Groupthink principles to see whether the decision process was affected by groupthink. 't Hart concludes that Janis consequently sacrificed objectivity in his methodology. Interestingly, however, 't Hart (1990) used similar protocol in his analyses of the 1940 Nazi invasion of Holland. For researchers, then, it appears that policy decisions are good places to find high-stress, high-risk group decision making.

Groupthink may be more intuitively appealing than empirically driven. The theory, however, continues to receive attention in research as well as in the popular press. In fact, Janis's thinking on groupthink has been quite influential in several fields of study, including communication, cognitive and social psychology, anthropology, and political science. Few would debate the failure of the foreign policy fiascoes outlined by Janis: massive violence and casualties, loss of confidence in governmental decisions, and policymaking gone wrong. For these reasons alone, Janis is credited with helping us identify and examine one type of group decision-making problem.