The Bias Everyone Else Has

A news story describes how people let their group loyalty color their judgment. A thought agrees at once, and it has someone else in view. It is not about itself. KTT counts that thought as a thought, noticed or not, even when it arrives as a small satisfied nod. In 2002, Emily Pronin, Daniel Lin and Lee Ross gave it a name: the bias blind spot. The sources read for this article are abstracts, a review by Pronin and a replication, not the full papers.

What they found

Across surveys and experiments, Pronin, Lin and Ross found that people see more bias in others than in themselves. People rated the average person as more affected by well-known biases than they rated themselves. The authors say that cognitive and motivational factors reinforce each other here, and they describe the result as an illusion of being less susceptible than peers.

Why the thought looks away

In 2007, Pronin and Matthew Kugler proposed one source: the introspection illusion. People judge themselves by their thoughts and feelings, which feel like direct evidence. They judge others by behavior, which is easier to check. The thought “my reasons were fair” feels like proof for the person who has it. In another person, the same sentence is not proof. A 2023 review by Pronin and Lori Hazel names the introspection illusion as a key source of the blind spot.

What later work found

A preregistered replication with a Brazilian sample in 2024 replicated two of the three hypotheses from the 2002 study. The main result held: people saw themselves as less susceptible to bias than others. The third did not hold in the same way. A 2020 replication also supports the effect. These are survey and laboratory studies. They show a pattern in how people rate themselves and others.

What is not known

Whether a person can learn to see their own bias by looking at their thoughts is not known. The theory says introspection is the problem, so looking harder inward may not help.

Whether the blind spot is the same in every culture is open. A Brazilian replication supports it in one more setting.

How the blind spot shows up in a single choice, as against a rating on a survey, is also open.