Irrationality refers to the quality of being illogical or unreasonable in thought or behavior. It often manifests when individuals make decisions based on emotions, biases, or flawed reasoning rather than objective facts. This can lead to choices that contradict their own best interests or established evidence. In psychology, irrationality is studied to understand how cognitive biases, such as confirmation bias or anchoring, influence human behavior. These biases can cause people to overlook important information or cling to false beliefs, impacting everything from personal decisions to broader societal issues, such as political opinions and economic choices.