This psychological concept refers to our tendency to favor information that aligns with our pre-existing beliefs while we often ignore information that contradicts them. Remember that friend of yours who always insists that their favorite basketball team is the best even when they're losing? That's confirmation bias in action!

Peter Wason, a cognitive psychologist, created a popular experiment in 1968 which showed how confirmation bias influences our decision-making.

Wason presented participants with a logical task involving four cards. The rule was "If a card has a vowel on one side, then it has an even number on the other side". Participants were asked to identify which cards needed to be turned over to verify this rule.

Most participants chose cards "A" or "A and 4" - but they were wrong! The correct answer was "A and 7". Why? Because to truly test the rule, you need to identify instances that can falsify the rule, not just confirm it.

So remember, it's like trying to prove that all swans are white - you'd need to find a non-white swan to really test your theory!

Some psychologists argue that "confirmation bias" doesn't fully explain our decision-making patterns. They propose the term "congruence bias" instead. This suggests our decisions are influenced by our failure to consider alternative hypotheses.