The engine behind the wheel: what has to be in place for a behaviour to happen.
How to read it. The six sub-types on the left feed the three components. All three components shape behaviour. Capability and opportunity also shape motivation (a great gym you cannot reach still saps the will to go). And behaviour feeds back on its own causes: doing it makes you more capable and more motivated, which is how a change takes hold, or, when the first attempts fail, unravels.
Work the wheel
This is the Behaviour Change Wheel. The hub is the gap (which of Capability, Opportunity, or Motivation is missing), and each wedge is one kind of fix. The skill is to read outward: once the gap is diagnosed, only certain fixes actually target it. For each case, click the wedge you would use.