This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: When humans are making decisions, they are known not to rely solely on their own considerations and the evidence available to them. Past behavioral science and psychology studies have shown that people are often also influenced by the choices and opinions of others.
For example, many people tend to conform to the judgments and opinions of the majority, even if they conflict with their own or with the information they are presented with. In behavioral science, this tendency is referred to as conformity bias. Researchers at the University of Toulouse-CNRS and the University of Leeds recently used a mathematical approach to investigate how groups of experts make decisions and whether dissent influences the reliability of their choices.
Their findings, published in the Journal of the Royal Society Interface, suggest that high levels of agreement or unanimity during group decision-making are not always signs of expertise and trustworthiness. "While reading a previous paper, we realized that a paradoxical—yet intuitive—result could emerge from Bayesian decision-making," Aurèle Boussard, first author of the paper, told Phys.org. "In this mathematical framework, individuals balance private and social information in an optimal way.
From that, it reasonably follows that the more individuals agree, the more likely the group is to be right. However, we found situations leading to the opposite conclusion, in which the more confident a group seems, the less trustworthy it is." Earlier observations by behavioral scientists suggest that a group's overconfidence in a decision can sometimes indicate conformity bias or other cognitive biases. In other words, individuals in the group might have simply agreed with the decision that the majority was leaning toward or may have made an unconsidered choice.
"We were surprised to predict a lower majority accuracy at high agreement (compared with slightly lower agreement, i.e., some dissent), so we decided to investigate," explained Boussard. "We started with the basic tools of probability theory to model how an individual would make the best decision given some information (both private and social). This is an idealized version of reality in which individuals are not assumed to be cognitively biased.
That idealization is, however, useful because it gives a clear baseline to which we can add specific biases, such as conformity—the tendency to align one's judgment with a group." There are numerous different ways of mathematically modeling conformity. In their paper, Boussard and colleagues used four distinct formulations: two information transfer schemes and two mathematical models. "We also varied the complexity of the decision, which is represented by the quality of the private information available to each individual," said Boussard.
Extract — continue reading at the source.
