One Bias to Rule Them All

All cognitive biases = one of a handful of fundamental beliefs + confirmation bias

Pablo Picasso, Girl Before a Mirror

I can explain it only by a weakness of the scholarly mind that I have often observed in myself. I call it theory-induced blindness: once you have accepted a theory and used it as a tool in your thinking, it is extraordinarily difficult to notice its flaws.

-Daniel Kahneman (1934-2024)

Psychologists have posited hundreds of cognitive biases over the years, from hindsight bias to ingroup-outgroup bias to the fundamental attribution error. They’ve even proposed a “bias bias”: a tendency to overestimate the impact of cognitive biases on (other) people’s thinking. Inventing and cataloguing biases seems to be one of psychologists’ favorite pastimes.

But a fascinating recent paper by Aileen Oeberst and Roland Imhoff argues that all our cognitive biases boil down to one of a handful of fundamental beliefs, coupled with just one “ultimate” bias. The fundamental beliefs include such ideas as “I make correct assessments” and “I am good.” And the ultimate bias is confirmation bias: the tendency to seek and favor information consistent with one’s preexisting views.

In this post, I’ll look at a range of common cognitive biases, and the six fundamental beliefs that give rise to them.