Why do group decisions often become extreme, and what are the causes and solutions?

In group decision-making, if initial opinions are adventurous or conservative, they can become increasingly extreme as the discussion progresses. This is called “group polarization,” and various theories explain why this happens. This polarization can lead to bad decisions, and you need a strategy to prevent it.

 

It’s easy to assume that getting a group of people together and talking to each other will lead to more rational conclusions because of the diversity of opinions, but in practice, group decision-making can sometimes lead people to go to the extremes rather than the other way around. This phenomenon of polarization, where a group’s initial opinions become more adventurous if they were adventurous, or more conservative if they were conservative, is known as group polarization.
This phenomenon can be surprisingly widespread in the decision-making process. For example, if you’re working on a team project at work and the initial idea is to take some risks, you’ll often find that as the discussion among team members progresses, they become more willing to take those risks. Conversely, if the initial idea is designed to be very safe, team members may tend to stick with the safer option over time. This tendency can lead to overly risky or overly conservative decisions that go beyond prudence.
So why does group polarization happen?
First, social comparison theory explains that group members tend to compare themselves to others and have a desire to be recognized by others. During a group discussion, if people feel that their argument is inferior to the other person’s, they will inadvertently express more extreme opinions. For example, if you thought a movie you went to with your friends was average, but more of your friends claimed that it was “really bad,” you might think that you didn’t enjoy it either, and you might be more inclined to make a stronger case for your criticism to gain support from the group. In this way, the group’s opinions become more and more extreme as the group’s mood strongly influences the individual’s opinion.
Second, the persuasive argumentation theory explains that as a group discussion progresses, members are exposed to new information or opinions, which opens them up to a variety of different and persuasive opinions that they may not have considered before. If someone in a group initially makes an opinion that is somewhat exaggerated, it is more likely that other members will gradually agree with them or make stronger arguments, and the group as a whole will move in an extreme direction. If a persuasive argument emerges from this process, it will likely dominate the group’s decisions.
Third, social identity theory relates group polarization to the phenomenon of conformity to group norms. People with higher levels of social identity identify themselves with their in-group. As a result, differences of opinion within the ingroup are minimized, and they are strongly influenced by the group’s norms and act in accordance with the group’s norms. In other words, differences of opinion between ingroup members are minimized, while differences between the outgroup and the ingroup are maximized, and over time, the ingroup’s opinions become differentiated from those of the outgroup and shift to more extreme directions. An example of this is when two political parties with different political tendencies become less unified and more divergent over time. This can also be easily observed in online communities, where groups with the same political leanings discuss a particular issue and see their opinions become more and more extreme over time.
This phenomenon of group polarization can lead to poor decision-making, where a group makes a decision without considering other alternatives or thinking diversely, a process known as groupthink. The negative tendency of groupthink is reinforced in highly cohesive groups, groups that are excluded from outside input and criticism, groups with overly authoritarian leaders, groups without democratic processes to present and evaluate alternatives, and groups under high stress. This raises the question of what are the group conditions for rational decision-making?
We also need to consider different strategies to prevent group polarization and groupthink. For example, deliberately assigning dissenting voices to maintain a diversity of perspectives within a group, or making the decision-making process more structured to ensure that different alternatives are fully explored. These strategies can help the group make more balanced decisions, rather than leaning toward extremes.