Concept
Motivated Reasoning
Motivated reasoning is the tendency to weigh evidence by what we want to be true: we accept welcome conclusions easily and hold unwelcome ones to a much stricter standard.
Motivated reasoning rarely feels like bias. It feels like being careful. Ziva Kunda's classic 1990 review explained how it works. Our wishes don't let us believe anything we like. Instead, they quietly steer which evidence we look for and how hard we scrutinise it. A pleasing claim gets the question "Can I believe this?", and one supporting study is enough. An unwelcome claim gets "Must I believe this?", and we hunt for flaws until we find one. Julia Galef calls this posture soldier mindset: reasoning whose job is to defend a belief you already hold. It speaks the language of war, with positions, attacks and grudging retreats. Its opposite is the scout, whose job is to draw an accurate map even when the map disappoints. Being clever is no protection, because it can simply make the defence more sophisticated. Clearer thinking starts with noticing which role you're playing.
A real-life example
Maya spent eight months building a feature she had championed. The usage data comes in, and only 4% of users have touched it. She immediately questions the tracking code, the launch timing and the sample. Two months earlier, five friendly pilot customers loved the feature, and she questioned nothing. The data didn't change her standards. Her stake did. The scout's question would have been: if this were a colleague's feature, what would I conclude from 4%?
How to use it
- 1When a conclusion pleases or stings you, notice which question you're asking: "Can I believe this?" or "Must I believe this?" Then apply the stricter one to both sides.
- 2Run the selective-standards test. Imagine the same evidence pointed the other way, and ask whether you would judge its quality just as harshly.
- 3Before you look at the data, decide what result would change your mind and write it down.