Thinking · 2 guides
Thinking errors
The mistakes we make before we say a word — and the ones we make the moment we start arguing.
Biases vs. fallacies#
These two ideas get mixed up constantly, so here is the short version. A cognitive bias is a systematic tilt in how people judge or decide: we lean on the first number we hear, we notice evidence that agrees with us, we overrate what is easy to recall. Biases are psychological; they happen whether or not anyone is arguing.
A logical fallacy is a defect in an argument: the conclusion doesn’t follow from the reasons given, even if it sounds as though it does. Fallacies are about the structure of reasoning, which is why philosophers, not psychologists, catalogued most of them.
| Cognitive bias | Logical fallacy | |
|---|---|---|
| What it is | A pattern in judgment | A flaw in an argument |
| Where it lives | In the thinker | In the reasoning as stated |
| Studied by | Psychology, behavioral economics | Logic, philosophy, rhetoric |
| Example | Anchoring on a list price | “Everyone buys it, so it must be good” |
A note on evidence#
Some famous findings in psychology have not held up when other labs repeated them. Where an effect is contested, our guides say so and link the replication work, instead of presenting a classic study as settled. Knowing which errors are well established is itself a guard against error.