Professionalism/Irving Janis and Groupthink

A mode of thinking that people engage in when they are deeply involved in a cohesive in-group, when the members' strivings for unanimity override their motivation to realistically appraise alternative courses of action.[1]

—Groupthink as defined by Irving Janis, principal investigator of Groupthink

Groupthink is a phenomenon that occurs when members of a cohesive group are concerned with quickly reaching a consensus in their decision making without critically analyzing and evaluating ideas. The term was coined by William H. Whyte in 1952 and was studied extensively by Irving Janis. Janis analyzed numerous foreign policy disasters such as Japanese attack on Pearl Harbor and Bay of Pigs and found group cohesion to be the cause.

Causes and Symptoms of GroupthinkEdit

Irving Janis identified a number of group properties that would lead to the emergence of groupthink:

  1. Directive and promotional leadership
  2. Cohesiveness of the group
  3. Insulation of the group from the outside
  4. Lack of methodical decision-making procedures[2]

Groupthink encompasses a number of symptoms which frequently lead to poor decision making:

  1. Illusions of invulnerability
  2. Illusions of unanimity
  3. Rationalization of the warnings
  4. Intolerance to those opposed to the group and whistle-blowers
  5. Self-censorship of ideas deviating from the group consensus
  6. Complete faith in the morality of the group

Case Studies of GroupthinkEdit

These case studies highlight the importance of recognizing and avoiding groupthink as a professional engineer.


Challenger was destroyed in a launching accident on January 28, 1986. Cause of the accident was attributed to a faulty O-ring on the solid-fuel rocket booster which failed in the cold weather. All seven crew members died on board, including a woman who would have been the first teacher in space.

From Janis’s perspective, groupthink was responsible for the Challenger disaster, specifically cohesiveness, directive leadership, and group insulation. This case exhibited many symptoms of groupthink: launch crew members rationalized warnings from the engineers, they had an illusion of invulnerability based on their past success, and the managers belittled the engineers for always wearing their "engineering hats" and stereotyped them as ignorant.

Pearl HarborEdit

Pearl Harbor demonstrates two symptoms of groupthink: illusions of invulnerability creating excessive optimism and encouraging risk taking, and rationalizing warnings that might challenge the group’s assumptions. Americans ignored the fact that Japan had a tendency to launch brutal attacks before declaring war.[3] In fact, the US government underestimated the Japanese' intentions and continued sending scrap iron, oil, and other raw materials to Japan well into 1940.[3] Nine years before the bombing of Pearl Harbor, Admiral Frank Schofield anticipated a possible attack on Hawaii from the Pacific. The military confirmed his theory that aircrafts attacking from the Pacific would be undetected and would wreak havoc on the harbor. Despite these results, the military refused to re-examine their defenses.

Bay of PigsEdit

The Bay of Pigs Invasion was an assault on Cuba in 1961 by approximately 1400 United States trained Cuban exiles. The invasion was an utter failure when about 20,000 Cuban soldiers ended the assault within three days. Irving Janis attributed the cause of the disaster to groupthink.

Janis attributed the causes of groupthink in the Bay of Pigs to cohesion, secrecy, biased leadership, and lack of critical methodology[1]. One group would make decisions started by another group--which contributed to cohesion--since many considered a good start to the presidential term to be more important than the decision. The Bay of Pigs was meant to be a surprise invasion, so secret meetings were held with little outside communication. Kennedy's presence at meetings inspired biased leadership since no one wanted to question his statements. Finally, they lacked methodical decision-making procedures. These factors all led to illusions of invulnerability, illusions of unanimity and suppression of personal doubt among advisers.

Cuban Missile CrisisEdit

Irving Janis used the Cuban Missile Crisis to contrast the disaster at the Bay of Pigs. The Cuban Missile Crisis was a thirteen day long diplomatic crisis where the United States fought to keep Soviet missiles from being set up in Cuba.

After witnessing the failure of his administration at the Bay of Pigs, Kennedy made significant changes to the way that decisions were made within his offices.

  1. Advisers were asked to join discussions, not only as representatives with narrow responsibilities, but ready to think critically about all aspects of policy.
  2. Meetings were more open and less formal. Guests were invited frequently and explicitly asked to voice detailed opinions.
  3. Rather than always meeting as a full Executive Committee, meetings consisted of subgroups which included various White House Staff.
  4. Kennedy frequently chose to not attend meetings so he would not influence the opinions of group members.

These changes significantly improved the decision-making process of Kennedy's administration and enabled them to successfully negotiate the removal of the missiles. When Janis evaluated the new decision making process, he determined that no symptoms of groupthink were evident.


Religion is “a specific fundamental set of beliefs and practices generally agreed upon by a number of persons or sects,”[4]. It is a group belief system, which involves organized behaviors and rituals. Directive leadership is a fundamental part of many religions, and homogeneity of members’ social background and ideology is inherent to religion in general,[5] which are both causes of groupthink.

Janis' Symptoms of Groupthink Demonstrated by ReligionEdit

Unquestioned belief in the morality of the group, causing members to ignore the consequences of their actions: As Charles Selengut states, “the history and scriptures of the world’s religions tell stories of violence and war as they speak of peace and love.”[6] This is demonstrated in 1063 when Pope Alexander II granted a papal standard and an indulgence to those killed in the Crusades.[7]

Stereotyping those who are opposed to the group as weak, evil, biased, spiteful, impotent, or stupid: Muslims and Christians use the word infidel as a slur against those of different faiths.[4]

Direct pressure to conform placed on any member who questions the group, couched in terms of "disloyalty“: Members of the Baha’i faith must shun those who are declared as “covenant breakers” and expelled from the religion[8]; and Jewish communities can declare Cherem on members, which is an exclusion of a person from the community, although since the Enlightenment this is a rare occurrence.

Mind guards, who are self appointed members who shield the group from dissenting information: The 1925 Butler Act was a Tennessee law prohibiting public school teachers from denying Biblical Creationism, which forbade the teaching of evolution and other theories of man’s origin.[9]

Research Findings and Laboratory TestsEdit

Questions can be raised as to the utility of using groupthink for research.

—Henningsen, Henningsen, Eden & Cruz[10]

According to Clark McCauley[5], groupthink occurs due to directive leadership, members’ homogeneous background and ideology, and isolation of the group from outside sources of information and analysis. A concept of groupthink has been extensively studied and challenged by the researchers.

In his book, Janis considered group cohesion to be the most important antecedent of groupthink [1]. Based on laboratory studies, many researchers such as Mullen, Anthony, Salas, and Driskell [11] found weak or no support for the hypothesized relationship between cohesion and groupthink symptoms. Esser[2], McCauley[5] and Tetlock[12] also found that the group cohesion is not predictive of groupthink. Hogg[13] argue that cohesiveness is not cause of groupthink because one cannot distinguish cohesiveness from friendship or social attraction.

In a study of variables such as cohesiveness, leadership, dominance, accountability, and threat, only two variables were supported to be causes of groupthink symptoms[14]. It was found that the insulated groups has tendency to consider fewer alternatives and groups with directive leaders use less available information[15].

Preventing GroupthinkEdit

After concluding his case studies, Janis proposed some techniques to prevent groupthink[1]. Awareness of the causes and symptoms of groupthink helps group members limit its negative effects.

  1. The group leader should assign each member the role of "critical evaluator" and encourage objections and criticism.
  2. Group leaders must describe the problem using unbiased statements to avoid partiality.
  3. The organization should set up several independent groups to tackle each problem.
  4. The group should periodically split into subgroups with different leaders to discuss ideas then reconvene to work out issues.
  5. Each group member should discuss issues with trusted associates outside of group meetings.
  6. Each meeting, one or more qualified outside experts should attend meetings and challenge ideas of group members.
  7. One member each meeting should be given the role of Devil's Advocate.
  8. The group should analyze all possible intentions of involved parties.
  9. After reaching preliminary consensus, each member should vividly voice all residual doubts about the decision

Janis' prevention proposals were based on his experience and observations but not scientifically validated. Although his suggestions make sense, they have not been scientifically proven. Overall, there is startlingly little research done on the practical applications of groupthink. [16] In the limited practical research on groupthink, Hart proposes adding 'group accountability' to the list of preventions[17]. The end goal in preventing groupthink is in positive decision outcomes, so even beyond preventing groupthink, the following suggestions are valuable.

  1. Create backup plans in case of failures
  2. Hold the decision making group accountable for their decisions[18]


Group decision-making or cohesion is not always a bad thing. Collective wisdom or Group wisdom is when shared knowledge by individuals and groups are used to solve problems and conflicts. As long as the group does not fall into the trap of groupthink, cohesiveness of a group is useful especially during decision-making in the military.

The following example cases are recommended for further studies:

  • North Korea
  • Watergate
  • Marshall Plan
  • Northern Rock
  • Vietnam War

Related words:

  • Abilene paradox
  • Bandwagon effect
  • Collective behavior
  • Communal reinforcement
  • Group polarization
  • Group serving bias
  • Herd behavior
  • Spiral of silence


  1. a b c d Janis, Irving L. Victims of Groupthink. Boston. Houghton Mifflin Company, 1972.
  2. a b Esser, James K. (1998). Alive and well after 25 years: A review of Groupthink research. Organizational Behavior and Human Decision Processes. Vol 73. pp. 116-141.
  3. a b Walsh, H. (1989). Groupthink (pp. 16). Hartland Publications.
  4. a b (2011)
  5. a b c McCauley, C. (1989). The nature of social influence in groupthink: Compliance and internalization. Journal of Personality and Social Psychology, 57, 250–260.
  6. Selengut, Charles (2008-04-28). Sacred fury: understanding religious violence. p. 1. ISBN 9780742560840.
  7. Handy, R., Lotz, D., Norris, R.,Walker, W. (1918). A History of the Christian Church (4th ed.), pp. 347. New York City: Scribner. Retrieved April 24, 2011, from
  8. Abdu'l-Bahá. (1992). The Will And Testament of ‘Abdu’l-Bahá. Mona Vale: Bahá'í Publications Australia. Retrieved April 26, 2011 from
  9. Moore, R. (2002). Evolution in the Courtroom: A Reference Guide (pp. 117). Santa Barbara: ABC-CLIO.
  10. Henningsen, D. D., Henningsen, M. L. M., Eden, J., & Cruz, M. G. (2006). Examining the Symptoms of Groupthink and Retrospective Sensemaking. Small Group Research, 37, 36-64.
  11. Mullen, B., Anthony, T., Salas, E., & Driskell, J. E. (1994). Group cohesiveness and quality of decision making: An integration of tests of the groupthink hypothesis. Small Group Research, 25, 189–204.
  12. Tetlock, P. E., Peterson, R. S., McGuire, C., Chang, S., & Feld, P. (1992). Assessing political group dynamics: A test of the groupthink model. Journal of Personality and Social Psychology, 63, 403–425.
  13. Hogg, M., Hains, S. 1998. "Friendship and group identification: a new look at the role of cohesiveness in groupthink." European Journal of Social Psychology. Vol. 28. pp 323-341.
  14. Park, W. (2000). A comprehensive empirical investigation of the relationships among variables of the groupthink model. Journal of Organizational Behavior, 21, 873–887
  15. Flowers, M. L. (1977). A laboratory test of some implications of Janis’s groupthink hypothesis. Journal of Personality and Social Psychology, 35, 888–896.
  16. Rose (2011). Diverse Perspectives on the Groupthink Theory. Emerging Leadership Journeys, Vol. 4 Iss. 1, 2011, pp. 37- 57.
  17. Mohamed, A. A., & Wiebe, F. A. (1996). Toward a process theory of groupthink. Small Group Research, 27(3), 416-430.
  18. Hart, P. (1998). Preventing groupthink revisited: Evaluating and reforming groups in government. Organizational Behavior and Human Decision Processes, 73, 306-326.