Confirmation Bias is the tendency of people to favor information that confirms their own beliefs, goals or desired outcomes (and ignore what doesn’t fit).
A definition of confirmation bias from the book Consumer Behavior:
“The tendency of consumers to interpret ambigious evidence as consistent with their current beliefs.”
A business example of confirmation bias is the hugely popular personality-type quizzes (e.g. which ‘Beatle member are you?’ or ‘What type of Ice Cream are you?’). When people take those quizzes they are typically reaffirming the opinion they already have in their mind (“I’m Mick Jagger of course”).
A trick of those quizzes is that most of the successful ones return you results that are positive (you’re unlikely to find one that asks ‘Which mass murderer are you?).
Why do people do this? According to PsyBlog:
“In an uncertain world, people love to be right because it helps us make sense of things. Indeed some psychologists think it’s akin to a basic drive.”