False consensus effect

In psychology, the false consensus effect, also known as consensus bias, is a pervasive cognitive bias that causes people to "see their own behavioral choices and judgments as relatively common and appropriate to existing circumstances". In other words, they assume that their personal qualities, characteristics, beliefs, and actions are relatively widespread through the general population. This false consensus is significant because it increases self-esteem (overconfidence effect). It can be derived from a desire to conform and be liked by others in a social environment. This bias is especially prevalent in group settings where one thinks the collective opinion of their own group matches that of the larger population. Since the members of a group reach a consensus and rarely encounter those who dispute it, they tend to believe that everybody thinks the same way. The false-consensus effect is not restricted to cases where people believe that their values are shared by the majority, but it still manifests as an overestimate of the extent of their belief. Additionally, when confronted with evidence that a consensus does not exist, people often assume that those who do not agree with them are defective in some way. There is no single cause for this cognitive bias; the availability heuristic, self-serving bias, and naïve realism have been suggested as at least partial underlying factors. The bias may also result, at least in part, from non-social stimulus-reward associations. Maintenance of this cognitive bias may be related to the tendency to make decisions with relatively little information. When faced with uncertainty and a limited sample from which to make decisions, people often "project" themselves onto the situation. When this personal knowledge is used as input to make generalizations, it often results in the false sense of being part of the majority. The false consensus effect has been widely observed and supported by empirical evidence. Previous research has suggested that cognitive and perceptional factors (motivated projection, accessibility of information, emotion, etc.