The fast system is an associative machine. It links ideas by similarity, cause, and mood, producing quick interpretations without asking permission.
A single cue can activate a network: words, images, stereotypes, memories. Once activated, the network shapes what feels normal, what feels likely, and what feels like “the obvious conclusion.”
Association is useful because it creates speed. It also creates vulnerability: primed thoughts can tilt judgment while you feel independent.
The slow system can resist, but only when it is alert and suspicious. Without that suspicion, association becomes reality, and you confuse what is easy to think with what is true.
To understand many biases, start here: the mind is not a neutral observer. It is a pattern-maker, always completing the picture.