The theory of cognitive dissonance was developed in the mid-1950s to explain why people of strong convictions are so resistant in changing their beliefs even in the face of undeniable contradictory evidence. It occurs when people feel an attachment to and responsibility for a decision, position or behavior. It increases the motivation to justify their positions through selective exposure to confirmatory information (Fischer, 2011). Fischer suggested that people have an inner need to ensure that their beliefs and behaviors are consistent. In an experiment that employed commitment manipulations, it impacts perceived decision certainty. Participants were free to choose attitude-consistent and inconsistent information to write an essay. Those who wrote an attitude-consistent essay showed higher levels of confirmatory information search (Fischer, 2011). The levels and magnitude of dissonance also play a role. Selective exposure to consistent information is likely under certain levels of dissonance. At high levels, a person is expected to seek out information that increases dissonance because the best strategy to reduce dissonance would be to alter one's attitude or decision (Smith et al., 2008).