Motivated reasoning is a phenomenon in cognitive science and social psychology in which emotional biases lead to justifications or decisions based on their desirability rather than an accurate reflection of the evidence. One of the common examples is when people disagree with something and then go online to “do their own research.”
Even though I knew about the bias, I first learned the term from The Scout Mindset book. The author Julia Galef lists two questions that go through people’s mind when they’re engaged in motivated reasoning:
- Must I believe it? Looking for an excuse to not believe.
- Can I believe it? Looking for an excuse to believe.
Later, I heard about it again in The Knowledge Project podcast episode with Jonathan Haidt as the guest:
If you’re a Homo sapiens, you evolved for group combat, you evolved for confirmation bias and motivated reasoning. We’re not really evolved to be academics or scientists searching for truth in an unbiased way. We evolve to basically CYA (cover your ass), and win in social competitions. But if you learn some skills, you can actually be very effective: as a teacher, as someone who persuades, as someone who changes people.
I recently read Positioning, a book from the 80s in which authors list three types of people. The last one is engaged in motivated reasoning.
- A sane person has a vision of the world in their mind. When the facts of the world collide with the vision in the head, the person changes the vision in the mind.
- An insane person has a vision of the world in their mind, and try to make the world conform to that vision.
- An unsane person finds it too cumbersome to constantly change opinions, so they stick to one. They find facts that validate the opinion and avoid facts that invalidate the opinion.