"In a 1994 Harvard study that examined people who had radically changed their lives, for instance, researchers found that some people had remade their habits after a personal tragedy, such as a divorce or a life-threatening illness. Others changed after they saw a friend go through something awful, the same way that Dungy's players watched him struggle.

Just as frequently, however, there was no tragedy that preceded people's transformations. Rather, they changed because they were embedded in social groups that made change easier. One woman said her entire life shifted when she signed up for a psychology class and met a wonderful group. "It opened a Pandora's box," the woman told
researchers. "I could not tolerate the status quo any longer. I had changed in my core." Another man said that he found new friends among whom he could practice being gregarious. "When I do make the effort to overcome my shyness, I feel that it is not really me acting, that it's someone else," he said. But by practicing with his new group, it stopped feeling like acting. He started to believe he wasn't shy, and then, eventually, he wasn't anymore. When people join groups where change seems possible, the potential for that change to occur becomes more real. For most people who overhaul their lives, there are no seminal moments or life-altering disasters. There are simply communities-sometimes of just one other person-~who make change believable.

One woman told researchers her life transformed after a day spent cleaning toilets-and after weeks of discussing with the rest of the cleaning crew whether she should leave her husband.

"Change occurs among other people," one of the psychologists involved in the study, Todd Heatherton, told me. "It seems real when we can see it in other people's eyes."

The precise mechanisms of belief are little understood. No one is certain why a group encountered in a psychology class can convince a woman that everything is different, or why Dungy's team came together after their coach's son passed away. Plenty of people talk to friends about unhappy marriages and never leave their spouse; lots of teams watch their coaches experience adversity and never
gel.

But we do know that for habits to permanently change, people must believe that change is feasible. The same process that makes AA so effective-the power of a group to teach individuals how to believe- happens whenever people come together to help one another change. Belief is easier when it occurs within a community!"
• The Power of Habit, Charles Duhigh