• This refers to a cognitive bias that causes people to grossly overestimate the extent to which other people share their opinions, beliefs, and feelings on issues.
• People on social media websites who are exposed to political and other viewpoints that are similar to their own, for instance, may start to believe that most people in the world share their thoughts.
• This often leads them to draw wrong conclusions about public support for their beliefs.
• The false consensus effect could thus also explain the surprise that follows unexpected election results.

Source:TH