Definition
Habit loop is the four-stage neurological cycle — cue → craving → response → reward — that produces and reinforces every habit. Each loop is a closed feedback circuit: the reward strengthens the association between the cue and the response, making the response more automatic the next time the cue appears.
Why it matters
How it works
The four stages are sequential and interdependent.
Cue triggers your brain to initiate a behavior. It is a piece of information that predicts a reward. The smell of coffee, the buzz of a notification, walking past the gym.
Craving is the motivational state behind the behavior — the wanting, not the having. You crave the state-change the response will produce, not the response itself (caffeine alertness, not the cup; status update, not the act of unlocking).
Response is the actual behavior, the thought or action you perform. Whether you can perform it depends on motivation (the craving) and ability (the friction in your environment).
Reward delivers the state change. It satisfies the craving and teaches the brain that this cue was worth noticing. The reward closes the loop and signals: remember this — do it again.
Run the cycle enough times and the response becomes automatic — the cue alone triggers the response without conscious thought. That is what we call a habit.