Inzlicht believes that willpower is not a finite resource but instead acts like an emotion. Just as we don't "run out" of joy or anger, willpower ebbs and flows based on what's happening to us and how we feel.

Is there a limit to willpower?

Their research was based on the “limited theory” of willpower, in which some people believe it is limited and needs to be replenished. However, others believe the opposite – that willpower is not limited and that they can activate it when they want to. ... Job's research has overturned both of these assumptions.

Is your willpower finite?

Michael Inzlicht, a professor of psychology at the University of Toronto and the principal investigator at the Toronto Laboratory for Social Neuroscience, believes willpower is not a finite resource but instead acts like an emotion.