Motivated reasoning
Etymology
A term from late-20th-century psychology, joining "motivated" (Latin "movere," to move) with "reasoning." Psychologist Ziva Kunda’s 1990 paper "The Case for Motivated Reasoning" fixed it as a standard concept.
noun phrase · /MOH-tuh-vay-tid REE-zuh-ning/
Reasoning aimed at reaching a conclusion you already want, rather than the one the evidence supports.
What it names
The way desire quietly steers thought — we scrutinize unwelcome facts and wave through welcome ones.
Example
His motivated reasoning let him dismiss every study that questioned the diet he’d already committed to.
Related idea
Confirmation bias is the mechanism — noticing confirming evidence; motivated reasoning is the goal that drives it — protecting a conclusion we’re emotionally invested in.