There's a standard story which says roughly "motivated reasoning in humans exists because it is/was adaptive for negotiating with other humans". I do not think that story stands up well under examination; when I think of standard day-to-day examples of motivated reasoning, that pattern sounds like a plausible generator for some-but-a-lot-less-than-all of them.

Examples

Suppose it's 10 pm and I've been playing Civ all evening. I know that I should get ready for bed now-ish. But... y'know, this turn isn't a very natural stopping point. And it's not that bad if I go to bed half an hour late, right? Etc. Obvious motivated reasoning. But man, that motivated reasoning sure does not seem very socially-oriented? Like, sure, you could make up a story about how I'm justifying myself to an imaginary audience or something, but it does not feel like one would have predicted the Civ example in advance from the model "motivated reasoning in humans exists because it is/was adaptive for negotiating with other humans".

Another class of examples: very often in social situations, the move which will actually get one the most points is to admit fault and apologize. And yet, instead of that, people instinctively spin [...]

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Outline:

(00:30) Examples

(03:42) So why do humans motivatedly reason, then?

(04:20) What? But then why didn't motivated reasoning evolve away?

(06:04) Ok, but then why do humans motivatedly reason?

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First published:
January 14th, 2026

Source:
https://www.lesswrong.com/posts/GnatTWjdfCNn6hrFM/why-motivated-reasoning

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Narrated by TYPE III AUDIO.

“Why Motivated Reasoning?” by johnswentworth

LessWrong (30+ Karma)