Echo chamber (media)

In the context of news media and social media, an echo chamber is an environment or ecosystem in which participants encounter beliefs that amplify or reinforce their preexisting beliefs by communication and repetition inside a closed system and insulated from rebuttal.^[2][3][4] The echo chambers function by circulating existing views without encountering opposing views, potentially leading to three cognitive biases: correlation neglect, selection bias and confirmation bias.^[5] Echo chambers may increase social and political polarization and extremism.^[6] On social media, it is thought that echo chambers limit exposure to diverse perspectives, and favor and reinforce presupposed narratives and ideologies.^[4][7]

The term is a metaphor based on an acoustic echo chamber, in which sounds reverberate in a hollow enclosure. Another emerging term for this echoing and homogenizing effect within social-media communities on the Internet is neotribalism.

Many scholars note the effects that echo chambers can have on citizens' stances and viewpoints, and specifically implications has for politics.^[8] However, some studies have suggested that the effects of echo chambers are weaker than often assumed.^[9]