Confirmation Bias
Also called: confirmatory bias, motivated reasoning
Confirmation bias is seeking and weighting evidence that supports what you already believe while discounting what doesn't. It's why a thesis grows more confident with research rather than being tested by it. The practical countermeasure is structural rather than motivational: write down in advance what evidence would make you sell, and have someone argue the opposite case before you commit.
Where this is taught
Definitions are the trailer. These free levels turn Confirmation Bias into something you play — one bite-size lesson, with worked examples, a quiz and XP.