automaticity

When a skill is practiced enough that it runs without the mind steering it — the centipede that walks without thinking about legs.

Automaticity is the endpoint of practice: a process that once needed conscious attention becomes fast, effortless, and outside working memory. The power law of practice describes the curve — reaction time drops logarithmically with trials, a smooth decline rather than a sudden cliff. The centipede effect is the disruption that occurs when attention is drawn back to an automatic process: the centipede that walks fine until someone asks how it moves its legs. In the castle, automaticity is the tacit layer's engine — the procedural knowledge that runs silently while the explicit layer narrates, and the reason the tacit-cost gap widens: the more automatic the judgment, the less of it passes through working memory where verbalisation can reach it.