# Managing Groups and Teams/Groupthink

Question: What is groupthink and how can a team prevent it?
Groupthink is a behavioral pattern exhibited by team members in an attempt to reduce conflict and reach consensus without critically analyzing an issue. In order for a team to achieve a high performing status, it is imperative that team members are fully aware of and make efforts to avoid falling victim to groupthink.

## Definition

Groupthink occurs when group members give priority to sustaining concordance and internal harmony above critical examination of the issues under consideration. Groupthink refers to a deterioration of mental efficiency, reality testing, and moral judgment that results from in-group pressures. Irving Janis referred to groupthink as a mode of thinking that people engage in when they are deeply involved in a cohesive in-group, when the members’ striving for unanimity override their motivation to realistically appraise alternative course of action.

## History

Groupthink has been used over the years to help understand group dynamics and why certain groups are successful and others lead to disaster. A considerable amount of social science literature shows that in circumstances of extreme crisis, group contagion occasionally gives rise to collective panic, violent acts of scapegoating, and other forms of what could be called group madness. Many researchers feel that groupthink arises out of highly cohesive groups (groups where there is a lot of mutual liking and respect) that are put in extreme circumstances, though there has been some debate about this conclusion (see Criticisms of groupthink).
In the 1950’s and 1960’s, other social psychologists such as Leon Festinger, Harold Kelley, and Stanley Schachter found that group cohesiveness increases when there is more member participation and group membership remains stable. Kurt Lewin, a social psychologist, found that when group cohesiveness is high, all members express solidarity, mutual liking, and positive feelings about attending meeting and carrying out the routine tasks of the group. Thus, highly cohesive groups are often high performing under normal circumstances.
Wilfred Bion, an eminent group therapist, investigated to what extent cohesion could also contribute to negative group outcomes. Bion described how the efficiency of working groups can be negatively affected by preconscious misconceptions of group members. His stated that by sharing basic assumptions that preserve the group, group members tend to lose regard for the work at hand and focus more on maintaining positive group relations. The higher the group cohesiveness, the more power the group has over norms, acceptance of goals, reduction in member anxiety, and a heightened level of group member’s self-esteem.
In 1972, Irving L. Janis coined the term “groupthink” after the Newspeak vocabulary used in George Orwell’s book 1984. Janis was an American research psychologist who studied at Yale University and was a professor at the University of California, Berkeley. Janis’ background in social sciences paved the way for his Groupthink theory.
Groupthink has been linked to many famous disasters where group decision making lead to the end result. Janis used historical events such as the Bay of Pigs, Pearl Harbor, and the escalation of the Vietnam War to explain the characteristics of Groupthink in policy making. An interesting aspect of Groupthink is that the theory is used to help explain group dynamics after the event has taken place. To this date, Groupthink has not been proven in a research study.

## Antecedent Conditions

According to Janis, there are three main antecedent conditions that encourage groupthink tendencies to occur. When these three conditions are present, the group is more suspect to groupthink.
The first condition is that decision makers constitute a cohesive group. For example, if the decision makers in the group have been working together for a long period of time and have had past successes, they will usually operate as a cohesive group.
The second condition is there are structural faults in the organization. Structural faults include: Insulation of the group, lack of traditional impartial leadership, lack of norms requiring methodical procedures, and homogeneity of members’ social background and ideology.
The third condition is that the group is in a provocative situational context. When a group experiences high stress from external threats the context is created. The threats are usually compounded with the fact that there is little hope of a better solution than what the leader of the group is offering. Another factor that induces the provocative situational context is low self-esteem within the group. The low self-esteem is usually induced by recent failures, excessive difficulties on decision-making that lowers each member’s sense of self-efficacy, and moral dilemmas.

## Symptoms

Irving L. Janis has identified eight main Symptoms_of_Groupthink: invulnerability, rationale, morality, stereotypes, pressure, self-censorship, unanimity, and mind guards. The eight symptoms can be divided into three specific types.:
* Overestimation of the Group
** Illusion of invulnerability: This symptom can alleviate fears of failure and prevent unnerving fears of failure during a crisis.
** Belief in inherent morality of the group: The shared belief that “we are a good and wise group” inclines them to use group concurrence as a major criterion to judge the morality as well as the efficacy of any policy under discussion. The members believe since the group’s objectives are good any means we decide to use must be good as well.
* Closed-Mindedness
** Collective Rationalization: The group will construct rationalizations in order to discount warnings and other forms of negative feedback that, taken seriously, might lead group members to reconsider their assumptions each time they recommit themselves to past decisions.
** Stereotypes of Out-Groups: This symptom is when the group uses undifferentiated negative stereotypes of opponents. This symptom enables the group to minimize decision conflicts between ethical values and expediency. Shared negative stereotypes of out-groups support the so-called “evil nature” of the enemy.
* Pressures Toward Uniformity
** Self-Censorship: Victims of Groupthink avoid deviating from what appears to be group consensus. The group members will keep silent about their misgivings and even minimize to themselves the importance of their doubts.
** Illusion of Unanimity: An illusion of unanimity is shared within the group concerning all judgments expressed by members who speak in favor of the majority view. This symptom is supported by the false assumption that any individual who remains silent during any part of the discussion is in full accord with what the others are saying.
** Direct pressure on dissenters: Members of the group will apply direct pressure on any individual who momentarily expresses doubts about any of the group’s shared illusions or who questions the validity of the arguments supporting a policy alternative favored by the majority.
** Self-appointed mind guards: This symptom protects the members from adverse information that might break the complacency they share about the effectiveness and morality of past decisions.

## Effects of Groupthink

Irving L. Janis calls the effects of groupthink “products”. The products are the consequences to poor decision making practices that lead to inadequate solutions to the problems under discussion. There are six products identified by Janis that are evident in groupthink situations.
The first product is when the group limits its discussions to a few alternative courses of action (often only two) without an initial survey of all the alternatives that might be worthy of considerations. The group ignores all possible solutions to an issue usually overlooking better solutions.
A second product of groupthink is when the group fails to reexamine the course of action initially preferred by the majority after they learn of risks and drawbacks they had not considered originally. This product is especially alarming because the group is not methodically thinking through the consequences of their decisions. In government and policy making situations, this product can have disastrous repercussions.
The third product is when the members of a group spend little or no time discussing whether there are not obvious gains they may have overlooked or ways of reducing the seemingly prohibitive costs that made rejected alternatives appear undesirable to them.
The fourth product is when the members of a group make little or no attempt to obtain information from experts within their own organizations who might be able to supply more precise estimates of potential losses and gains. The members are afraid to find any information that might sway the group from their decided course of action.
The fifth product is when the members of a group show positive interest in facts and opinions that support their preferred policy. In turn, they tend to ignore facts and opinions that do not support their preferred policy. Any information that supports the decision is embraced and any information that disputes the decision is swept under the table. The groupthink tendency prevails because the group does not want their decision to be threatened in any way.
The sixth and final product identified by Janis is when the members of a group spend little time deliberating about how the chosen policy might be hindered by bureaucratic inertia, sabotaged by political opponents, or temporarily derailed by common accidents. They fail to work out contingency plans to cope with foreseeable setbacks that could endanger the overall success of their chosen course.

## Ways to prevent groupthink

There are many different opinions on how to prevent groupthink. However they all have the same underling theme: Create an open environment for ideas and participation. There are five simple steps which can be taken to create this environment:
* Leaders should allow each member to challenge ideas and present objections.
* Members should talk about and solicit ideas with people outside the group.
* Outside experts should be invited to attend meetings.
* Avoid expressing opinions about the preferred outcome.
* Assign Devil's_Advocate at all meetings to challenge any and all ideas.

## Historical Examples
### Bay of Pigs Invasion

The idea for the Bay_of_Pigs_Invasion was first suggested by John F. Kennedy’s main political opponent, Richard M. Nixon. As Vice President during the Eisenhower administration, Nixon had proposed that the United States government secretly send a trained group of Cuban exiles to Cuba to fight against Castro. In March 1960, acting on Nixon’s suggestion, President Dwight D. Eisenhower directed the Central Intelligence Agency to organize Cuban exiles in the United States into a unified political movement against the Castro regime and to give military training to those who were willing to return to their homeland to engage in guerrilla warfare. The CIA put a large number of its agents to work on this clandestine operation, and they soon evolved an elaborate plan for a military invasion. Apparently without informing President Eisenhower, the CIA began to assume in late 1960 that they could land a brigade of Cuban exiles not as a band of guerrilla infiltrators but as an armed force to carry out a full-scale invasion.
Two days after the inauguration in January 1961, President John F. Kennedy and several leading members of his new administration were given a detailed briefing about the proposed invasion by Allen Dulles, head of the CIA, and General Lyman Lemnitzer, chairman of the Joint Chiefs of Staff. During the next eighty days, a core group of presidential advisers repeatedly discussed this inherited plan informally and in the meeting of an advisory committee that included three Joint Chiefs of Staff. In early April 1961, at one of the meetings with the President, all the key advisers gave their approval to the CIA’s invasion plan. Their deliberations led to a few modifications of details, such as the choice of the invasion site.
On April 17, 1961, the brigade of about fourteen hundred Cuban exiles, aided by the United States Navy, Air Force, and the CIA, invaded the swampy coast of Cuba at the Bay of Pigs. Nothing went as planned. On the first day, none of the four ships containing reserve ammunition and supplies arrived; the first two were sunk by planes in Castro’s air force, and the other two promptly fled. By the second day, the brigade was completely surrounded by twenty thousand troops of Castro’s well-equipped army. By the third day, about twelve hundred members of the brigade, comprising almost all who had not been killed, were captured and ignominiously led off to prison camps.
Symptoms:
* Overestimation of the Group
** The CIA felt that the Cuban exiles would carry out the invasion without any ground support from the United States.
** They also felt that Casto’s army was so weak that the Cuban exiles could hold his army at the beachhead.
** This plays into the first example that the Cuban exiles would carry out the invasion no matter what.
* Closed-Midedness
** They assumed that if the brigade did not succeed they could just retreat to the Escambray Mountains and reinforce guerrilla units that were there.
** They also assumed that the invasion would spark uprisings behind the lines, and that those uprisings would support the exiles and prompt the top poling of the Castro regime.
* Pressures Toward Uniformity
** The invasion was actually an idea from the Presidency of Dwight D. Eisenhower, which had not been implemented. Once John F. Kennedy became President he took over the invasion and was given a brief overview of what they had planned. Also, the briefing was given by two members of the original group that had devised the plan. The new Presidency most likely felt as though they needed to implement the plan from the prior Presidency, and as a result went forward with the invasion without thinking through the entire situation.
Some of the effects of groupthink that were apparent in the Bay of Pigs example were:
* The group did not reexamine the course of action initially preferred by the majority. As mentioned above, this was a result of President John F. Kennedy taking over once he had became President and not reevaluating the situation and decisions that had been made.
* The group also limited discussion to a few alternative courses of action. To this degree Janis Jarvis mentions that several members of the existing group debriefed the President on the plan of action.

### Titanic

The RMS Titanic was an Olympic-class passenger liner owned by the White Star Line and was built at the Harland and Wolff shipyard in Belfast, in what is now Northern Ireland. At the time of her construction, she was the largest passenger steamship in the world.
Shortly before midnight on 14 April 1912, four days into the ship's maiden voyage, Titanic struck an iceberg and sank two hours and forty minutes later, early on 15 April 1912. The sinking resulted in the deaths of 1,517 of the 2,223 people on board, making it one of the deadliest peacetime maritime disasters in history. The high casualty rate was due in part to the fact that, although complying with the regulations of the time, the ship did not carry enough lifeboats for everyone aboard. The ship had a total lifeboat capacity of 1,178 people, although her maximum capacity was 3,547.
The Titanic was designed by some of the most experienced engineers, and used some of the most advanced technologies available at the time. It was popularly believed to have been unsinkable. It was a great shock to many that, despite the extensive safety features, the Titanic sank. The frenzy on the part of the media about Titanic's famous victims, the legends about the sinking, the resulting changes to maritime law, and the discovery of the wreck have contributed to the continuing interest in, and notoriety of, the Titanic.
Symptoms
* Overestimation of the Group
** The Titanic was viewed as being the safest ship ever built and therefore was viewed as being “unsinkable”. As a result the ship was only equipped with 20 lifeboats, which was only enough to carry half of the ships total passengers.
** The rudder construction was also determined to be much smaller than needed in comparison to the size of the ship.
* Closed-Mindedness
** The SS California, another ship in the area, had warned the Titanic by radio of the ice packs, for which it had stopped for the night. The Titanic ignored the warnings.
* Pressures Toward Uniformity
** Everyone bought into the idea that the Titanic was “unsinkable”.
Some of the effects that were apparent in the sinking of the Titanic include:
* Members showed positive interest in facts and opinions that supported their preferred policy, such as the fact that the Titanic was the largest passenger ship of its time and the opinion that the Titanic was unsinkable. While at the same time ignoring facts such as the fact that the rudder construction was too small and the opinion from the SS California which had stopped for the night because of the ice packs.

## Recent Examples
### 9-11-2001

The unfortunate truth is that, especially in the case of analyzing and recognizing Groupthink, hindsight is 20/20.
Several events (real and imagined, catastrophic and global) in the last ten years possess Groupthink symptoms. Though it is impossible to pinpoint Groupthink as the catalyst for these events, it is interesting to consider how it may have contributed to their development.
Take, for example: attacks in 2001. “Warnings about Al Qaeda may have gone unheeded as the incoming administration may have unwisely ranked the Al Qaeda threat somewhere lower than other objectives like national missile defense, China and the ousting of Saddam Hussein,” suggests a writer who wrote about the attacks. Paul Wolfowitz is also quoted as saying, "You give bin Laden too much credit. He could not do all these things," before the attacks occurred. These quotes suggest the presence of an illusion to invulnerability; rationalizing warnings to change the group’s assumptions; and stereotyping those who are opposed to the group as weak, evil, biased, spiteful, disfigured, impotent, or stupid. Whether the other characteristics of Groupthink were present is a question left to those who were present in the national security meetings.

### Y2K

Another example can be found in the Y2K scare prevalent in 1999. In this instance the group is different than others discussed: instead of from a centralized unit of individuals, Y2K was perpetuated by programmers across the globe. Sam Meddis had this to say about Y2K February of 1999. "My point is that Y2K has already consumed more effort, money and angst than is merited. At this point the problem has less to do with computer code than with psychology. If we march on like lemmings convinced that major disaster is inevitable, then our hysterical actions might make it so. We'll have our doomsayers, not our machines, to thank for that."
Five years after the year 2000 arrived, Larry Seltzer, of eWeek, had this to say, "What we all should have argued for at the time was perspective: A focus on worst-case planning is usually unwarranted."
A USA Today columnist who resisted Y2K paranoia received this letter from a programmer:
* "First, the bad news: this problem is real, very big, and isn't going to be fixed in time…There is no likelihood whatsoever that the banking system is going to make it, nor the power grid as a whole. Therefore, we are in for a major disaster. The good news? You (and all the other pollyannas who have your head stuck in the sand) will stop consuming valuable resources, like air. Too bad that you may convince others not to protect themselves as well, but I guess that's another example of Darwinism in action. By the way, I am a computer programmer with almost 30 years experience in the field, and I have nothing to sell regarding Y2K. I wonder if you can twist that into some reason that my opinions should be disregarded?"
This letter gives interesting insight into this particular programmer’s thought process and potentially other programmers as well. The quote reveals unquestioning belief in the morality of the group, stereotyping those who are opposed to the group, illusions of unanimity among group members, and pressure on the columnist to conform to the group’s thinking. This programmer is, in affect, playing the role of a mind guard—shielding the group from dissenting information.

## Criticisms of groupthink

Despite the widespread acceptance of the groupthink theory, it is not without criticism. In his essay “So Right It's Wrong: Groupthink and the Ubiquitous Nature of Polarized Group Decision Making“ Robert Baron explores skepticism around the groupthink model by scholars involved in further analysis and testing of the theory. Baron suggests that the strength and acceptance of the model is based on popular culture’s predisposition toward a familiar social scenario and symptoms rather than on scientific findings.
Scientific study of the groupthink theory is rare as he states, “The majority of reports take the form of group decision case studies or historical sampling studies.” His research sites papers from academics familiar with the groupthink theory, such as a 1980 Longley and Pruit paper proposing that “the dangers posed by selective historical analysis, the possibility that the groupthink symptoms in Janis’s historical examples (particularly self censorship of dissent) might be more a result of group stage (early formation) than a function of Janis’s antecedent conditions (crisis, cohesion, directive leadership, etc.) and the argument that suppression of dissent might be functional in certain group settings.”
He also sites studies which provide significant supporting evidence contrary to the model. Data taken from studies such as R.J. Brown’s study on “Minimal group situations and intergroup discrimination” (1980) include scientific testing of the model with conclusions that dispute some of Janis’s claims. “It clearly is not the case, as Janis had surmised, that cohesion leads to poor decision making. Indeed, all the evidence suggests that it is unrelated to decision quality or may even be associated with better decision processes.” In addition Teltlock ( 1991) found that “neither degree of crisis nor cohesion was reliably related to decision quality of major national policy decisions.”
Baron goes on to further investigate the groupthink theory and historical scientific testing. He dissects Janis’s conditions for groupthink and proposes a revised model. His “ubiquity model” identified three antecedent conditions for groupthink phenomena to occur, and separates these from less well researched “amplifying conditions.”
Antecedent Conditions:
* Social Identification: Allegiance and social identity with the group forms because of common goals, history, or shared fate. Information has more influence when it originates from this in-group source as it receives more attention and elaboration.
* Salient Norms: Norms emerge within the group serving to bias discussion towards commonly held information, a symptom similar to Stasser’s “hidden profile paradigm.”
* Situational Low Self Efficacy. When presented with especially challenging problems, group members will refrain from proposing non-conforming ideas unless they are very confident in its success, and this confidence is reduced when the problem is more challenging resulting in suppression of counter arguments, and elevation of in-group ideas.
Brown concludes that these three phenomenon are far more common than Janis proposes and are “necessary and sufficient” for groupthink to occur. He identifies other aspects of Janis’s model merely as “amplifying conditions” which may decrease decision quality but are not necessary for groupthink symptoms to present themselves.
Amplifying Conditions
* Threat or Crisis – The time consuming democratic process becomes dangerous when rapid and deceive action is critical.
* Intense Cohesion – Crisis stimulates dependency needs
* Member Insecurity – Heightens desire for social identification making members more susceptible to group norms.
* Directive Leadership – Strong leadership more clearly identifies and establishes group norms, strengthening groupthink reactions.
This model accounts for persistence of groupthink phenomenon in even the most minor of group settings, rather than the intense and historically significant cases that Janis’s model focuses on. Barons “ubiquity model,” proposes that the majority of Janis’s conditions are “not necessary to trigger such phenomena as polarized judgment, out-group stereotyping, self censorship, and the illusion of consensus.” He shows that amplifying conditions need further laboratory study to show any meaningful relationship to groupthink phenomena. The conclusion that groupthink symptoms are far more widespread than Janis’s claims and that many of the symptoms are not an invariant feature of group decision making but rather amplifying conditions that require more study provides a less well known, but more well supported theory.

## Conclusion

An interesting point to consider is that when groups fail, we call the culprit Groupthink; when groups succeed, we call the culprit Synergy. Could an observer diagnose a group’s behavior as Groupthink versus synergy before the outcome is realized? Or are groups consigned to wait for the end before recognizing what behavior was involved? The danger of reflecting back is that people may focus only on supporting evidence—blaming Groupthink or synergy, as the case may be. The luging accident in the 2010 Winter Olympics carries the thrill of Groupthink analysis, whereas the commercial success of Disney’s Animation Studios during the 1990’s is heralded as pure synergy.
The answer to this question may some day be decided, but the difficulty in ensuring synergistic results is sure to continue. Synergy and Groupthink appear to be two faces on one coin, where a combination of external forces contributes in deciding which side lands face-up. As Groupthink is a relatively new study (since the 1970’s) perhaps continued research will weigh the chances so that when the coin is tossed, we can safely call out, “Synergy.”

## References

* ↑ 1.Kroon, Marceline B.R. Effects of accountability on groupthink and intergroup relations: Laboratory and field studies. Amsterdam: Thesis Publishers, 1992.
* ↑ Janis, Irving L. Groupthink. Boston: Houghton Mufflin Company, 1982.
* ↑ Janis, Irving L. Groupthink. Boston: Houghton Mufflin Company, 1982.
* ↑ Janis, Irving L. Groupthink. Boston: Houghton Mufflin Company, 1982.
* ↑ Janis, Irving L. Groupthink. Boston: Houghton Mufflin Company, 1982.
* ↑ Janis, Irving L. Groupthink. Boston: Houghton Mufflin Company, 1982.
* ↑ Janis, Irving L. Groupthink. Boston: Houghton Mufflin Company, 1982.
* ↑ Janis, Irving L. Groupthink. Boston: Houghton Mufflin Company, 1982.
* ↑ Janis, Irving L. Groupthink. Boston: Houghton Mufflin Company, 1982.
* ↑ Janis, Irving L. Groupthink. Boston: Houghton Mufflin Company, 1982.
* ↑ Janis, Irving L. Groupthink. Boston: Houghton Mufflin Company, 1982.
* ↑ Janis, Irving L. Groups: Pressures, decisions, and conflicts. “Groupthink.” Psychology Today Magazine, November 1971. Page 443.
* ↑ Janis, Irving L. Groups: Pressures, decisions, and conflicts. “Groupthink.” Psychology Today Magazine, November 1971. Page 442-443.
* ↑ Janis, Irving L. Groups: Pressures, decisions, and conflicts. “Groupthink.” Psychology Today Magazine, November 1971. Page 444.
* ↑ Janis, Irving L. Groups: Pressures, decisions, and conflicts. “Groupthink.” Psychology Today Magazine, November 1971. Page 445.
* ↑ Janis, Irving L. Groups: Pressures, decisions, and conflicts. “Groupthink.” Psychology Today Magazine, November 1971. Page 445-446.
* ↑ Janis, Irving L. Groups: Pressures, decisions, and conflicts. “Groupthink.” Psychology Today Magazine, November 1971. Page 444-445.
* ↑ Janis, Irving L. Groups: Pressures, decisions, and conflicts. “Groupthink.” Psychology Today Magazine, November 1971. Page 446.
* ↑ Janis, Irving L. Groups: Pressures, decisions, and conflicts. “Groupthink.” Psychology Today Magazine, November 1971. Page 447.
* ↑ Janis, Irving L. Groupthink. Boston: Houghton Mufflin Company, 1982.
* ↑ Janis, Irving L. Groupthink. Boston: Houghton Mufflin Company, 1982.
* ↑ Janis, Irving L. Groupthink. Boston: Houghton Mufflin Company, 1982.
* ↑ Janis, Irving L. Groupthink. Boston: Houghton Mufflin Company, 1982.
* ↑ Janis, Irving L. Groupthink. Boston: Houghton Mufflin Company, 1982.
* ↑ Janis, Irving L. Groupthink. Boston: Houghton Mufflin Company, 1982.
* ↑ Janis, Irving L. Victims of Groupthink. Boston. Houghton Mifflin Company, 1972, page 148-149
* ↑ http://www.hodu.com/groupthink.shtml
* ↑ Janis, Irving L. Groupthink. Boston: Houghton Mufflin Company, 1982.
* ↑ Richard Howells The Myth of the Titanic
* ↑ http://en.wikipedia.org/wiki/Titanic
* ↑ Zeller, Tom. “The World; So Many Voices, So Many Versions” New York Times. Published: April 11, 2004;http://www.nytimes.com/2004/04/11/weekinreview/the-world-so-many-voices-so-many-versions.html?scp=2&sq=administration%20knew%20about%209/11&st=cse; Accessed March 1, 2010.
* ↑ Meddis, Sam Vincent. "Don't Hold Breath for Y2K Disaster." USA TODAY. Feb. 15, 1999.http://www.usatoday.com/tech/columnist/ccc0215.htm. Accessed February 21, 2010.
* ↑ Seltzer, Larry. "Some Perspective 5 Years After Y2K." http://www.eweek.com/c/a/Security/Some- Perspective-5-Years-After-Y2K. 2005-01-03. Accessed February 21, 2010.
* ↑ Meddis.
* ↑ Baron, R. S. (2005). So Right It's Wrong: Groupthink and the Ubiquitous Nature of Polarized Group Decision Making. In Zanna, Mark P (Ed.) Advances in experimental social psychology, Vol. 37. (219-253). San Diego. Elsevier Academic Press.
* ↑ Longley, J., & Pruitt, D. G. (1980). Groupthink: A critique of Janis's theory. In L. Wheeler (Ed.), Review of Personality and Social Psychology (pp. 507-513). Newbury CA: Sage.
* ↑ Brown, R. J., Tajfel, H., & Turner, J. C. (1980) Minimal group situations and intergroup discrimination: Comments on the paper by Aschenbrenner and Shaeffer. European Journal of Social Psychology. 10, 399-414.
* ↑ Tetlock, P. E., (1979). Identifying victims of groupthink from public statements of decision makers. Journal of Personality and Social Psychology, 37, 1314-1324.
* ↑ Stasser, G., & Stewart, D.D. (1992). Discovery of hidden profiles by decision-making groups: solving a problem vs. making a judgment. Journal of Personality and Social Psychology. 63:426–34