You finish making tea and reach for the book beside your chair. Repeating an action in a recurring setting can build an association between the setting and the response. That is one way habits are understood in research.

James Clear’s popular four-part framework uses cue, craving, response and reward. It can prompt useful questions about a situation, what you expect, what you do and what follows. It is an organising framework, not a complete neurological model or proof that every action contains a conscious craving.