Motivated reasoning and public opinion.

Citizens, especially those who are knowledgeable and care the most about politics, are motivated to defend their beliefs and attitudes in the face of discrepant information. These motivated biases strongly influence the way people think about health care policies and the politicians and parties that propose or attack these contentious policies. Three cognitive mechanisms are identified: a prior belief effect, confirmation bias, and disconfirmation bias. Together, these information processes conspire to produce persistence and polarization of opinion on health care policies.