In their book “Willpower: Rediscovering the Greatest Human Strength,” Roy F. Baumeister and John Tierney share an amazing amount of information about willpower, or self-control. One interesting point they make is that a number of studies have shown two particular lessons concerning human willpower:
“1. You have a finite amount of willpower that becomes depleted as you use it.
2. You use the same stock of willpower for all manner of tasks.”
So your supply of willpower is fixed and is depleted by any number of activities – studying, exercising, dieting, being patient with others. What conclusions...