The false-consensus effect or false-consensus bias is a cognitive bias whereby a person tends to overestimate how much other people agree with him or her. There is a tendency for people to assume that their own opinions, beliefs, preferences, values and habits are 'normal' and that others also think the same way that they do. This cognitive bias tends to lead to the perception of a consensus that does not exist, a 'false consensus'. This false consensus is significant because it increases self-esteem. The need to be "normal" and fit in with other people is underlined by a desire to conform and be liked by others in a social environment.
The false-consensus effect is not necessarily restricted to cases where people believe that their values are shared by the majority. The false-consensus effect is also evidenced when people overestimate the extent of their particular belief is correlated with the belief of others. Thus, fundamentalists do not necessarily believe that the majority of people share their views, but their estimates of the number of people who share their point of view will tend to exceed the actual number.
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.
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.
The false-consensus effect is not necessarily restricted to cases where people believe that their values are shared by the majority. The false-consensus effect is also evidenced when people overestimate the extent of their particular belief is correlated with the belief of others. Thus, fundamentalists do not necessarily believe that the majority of people share their views, but their estimates of the number of people who share their point of view will tend to exceed the actual number.
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.
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.