Having strong willpower
Duhigg says “dozens of studies show that willpower is the single most important keystone habit for individual success.”
It all comes down to self-discipline. How do you know if you have it? One way to measure self-discipline, Duhigg writes, is to put people in a room with cookies and radishes and assign them one of the foods. Those who eat the other food, which will likely be the cookie, aren’t using their willpower.
He cites a 2005 University of Pennsylvania study that says students with high self-discipline perform better than those with a high IQ. “They had fewer absences and spent less time watching television and more hours on homework,” Duhigg writes.