Motivated reasoning is reasoning steered by the conclusion you want rather than by the evidence. It differs from confirmation bias in its source. Confirmation bias favours whatever you already believe, even about things you do not care about. Motivated reasoning comes from a stake in the answer: your self-image, your group, your money, your health. Its signature is a double standard for evidence. For a welcome conclusion you ask, 'Can I believe this?', and almost any support will do. For an unwelcome one you ask, 'Must I believe this?', and you search for flaws until you find one. In studies, people shown the same research method judged it sound when its result matched their views and flawed when it did not. Motivated reasoning is not lying; it feels like careful thinking from the inside, because you really are scrutinising, just only one side. Wishful thinking is its simplest form: rating a hoped-for outcome as more likely because you hope for it. The practical check is to notice when you have a stake, then ask whether you would accept the same evidence, at the same quality, for the conclusion you do not want. After this Concept you can tell motivated reasoning from plain confirmation bias, and spot the 'can I' versus 'must I' double standard in an argument, including your own.
Confirmation bias and motivated reasoning explain why people believe what they want to be true and ignore evidence against it. Confirmation bias is the habit of seeking and accepting only information…