Steel says motivational failures such as difficulty in sticking to diets and exercise regimes -- frequently the focus of New Year's resolutions -- are related to procrastination because impulsiveness is often at the root of the failure. "Temptations that are close at hand are difficult to resist. Addicts often relapse after returning from treatment facilities because drugs and alcohol become easily available and daily habits reassert themselves. Or we load up on bread in the restaurant before the meal is served. Or we check our email 10 times an hour instead of completing a project."

The good news is that willpower has an unusual capacity. "The old saying is true: 'Whether you believe you can or believe you can't, you're probably right'," Steel says. "And as you get better at self control, your expectancy about whether you can resist goes up and thus improves your ability to resist."

Steel has also come up with the E=mc2 of procrastination, a formula he's dubbed Temporal Motivational Theory, which takes into account factors such as the expectancy a person has of succeeding with a given task (E), the value of completing the task (V), the desirability of the task (Utility), its immediacy or availability (Γ) and the person's sensitivity to delay (D).

It looks like this and uses the Greek letter Γ (capital gamma): Utility = E x V / ΓD