Pearl Harbor, the Bay of Pigs Invasion, the Vietnam War, the Watergate Scandal, NASA’s Challenger and Columbia shuttle disasters, and the invasion of Iraq in 2003. Psychologists have linked all of these tragic events to the concept of groupthink. As Dr. Irving Janis originally described in 1972 in in his pioneering book, Victims of Groupthink, groupthink occurs when likeminded people gather to make a decision, and due to social conformity, they all gravitate towards the same conclusion, without fully analyzing all sides of the issue.

There are a number of factors that make groupthink more likely, including high group cohesiveness, high stress situations, a closed leadership style by the leader of the group (i.e., a style by which the leader states his or her decision first, and suppresses dissenting views).

In a fascinating paper entitled “Groupthink and the Sanhedrin: An Analysis of the Ancient Court of Israel Through the Lens of Modern Social Psychology,” Rabbi Dr. Eliezer Schnall and Dr. Michael Greenberg argue through various examples from the Talmud that the laws regulating the Sanhedrin serve to counteract groupthink. The Sanhedrin tended to be a group of like-minded individuals who were in charge of making very important decisions in high stress situations, many of which had life or death consequences. Without proper checks in place, they were in danger of groupthink.

The plethora of Talmudic proofs that they cite to bolster their argument find their conceptual roots within Parshat Mishpatim. In a sharp formulation, the verse states “You should not follow a multitude to do evil” (Exodus 23:2). While some understand this as a general exhortation to everyone not to associate with groups of people who are not behaving appropriately (Rabbeinu Bechaye), most commentators argue that the verse is speaking directly to judges (see, e.g., Rashi).

Despite the fact that all the other judges may decide that someone is either guilty or innocent, if one judge is convinced based on his own well-thought-out process that the others are incorrect, he is obligated to state his dissenting opinion. Even though there may be great group and social pressure to suppress his opinion and let the decision be unanimous, he must state his argument.

The verse concludes “and do not respond to a disagreement by yielding to the majority to prefer [the law],” which also lends itself to a number of possible interpretations by the commentators but seems to reiterate the importance of not perverting justice just to conform to the majority (see HaEmek Davar). Rashi, quoting the Sages, points out that the word riv (disagreement), which should be spelled Reish-Yud-Vet, is spelled in the verse without the middle Yud (just Reish-Vet). This allows for a non-literal reading of the word as Rav, meaning teacher. According to this interpretation, the message is that one should not disagree with one’s teacher when deciding a legal ruling. Yet, because following this idea would suppress a judge’s honest opinion, the rule in the Sanhedrin is that the less experienced judges must give their opinions first, before listening to their teachers or the experts’ decisions. This open leadership style is essential for avoiding groupthink.

Despite the fact that none of us sit on the Sanhedrin, the lessons gleaned are generalizable to other situations. Broadly speaking, standing firm behind what is right and just even though most others disagree, is an important trait to inculcate. Additionally, to whatever extent we make decisions as a group, we should do our best to counteract the threat of groupthink by modeling open leadership styles and encouraging dissenting opinions.