The mechanic of motivated reasoning.
There are psychological mechanisms that influence the way people think and believe. People believe what they want to believe even if their belief is leading them to process information in a biased sense. This is because the psychological process leading them can be affected in many ways by people’s motivations driving to biased beliefs. Their belief ends up changing their choices and preferences. Motivated reasoning is guided by motivated beliefs in the service of self-interest to be sure but with reasoning either way. People tend to reason by the goals that they are trying to achieve. The big deal is that people have many goals ranging from imperatives of survival and reproducing to more proximate that helps us survive. For instance, maintaining social and cooperative relationships, achieving social status and having a consistent belief that enables effective action. A perfect example of motivated reasoning is when a person chooses to preserve a favourable identity. For a person to maintain a positive self-regard; they unwillingly discount unflattering or unpopular opinion that contradicts their self-image. Individuals engage in motivated reasoning as a way of avoiding cognitive dissonance. The mental discomfort people experience when confronted by opposing information, especially on matters that directly relate to their mental health and happiness.