Many of our habits—often the bad ones—are formed as a result of our efforts to relieve tension or anxiety. Sharon Rowe, 56, an entrepreneur in Ossining, New York, cofounded Ecobags.com, a pioneer in the reusable-bag industry. Like many other small-business owners, she felt constantly on call, hypervigilant for any sign of a snafu. “The sound of an incoming e-mail or text was my cue,” she recalls. “When I did not have my phone, I was anxious, and when I did have it, I was constantly checking it.” Her routine was to interrupt whatever she was doing to check the screen. Her reward was either the satisfaction of a pleasant social connection (one of the most powerful human cravings) or the release of anxiety that comes from knowing she had headed off a work problem. But her habit became “an overwhelming time suck,” she says, and it annoyed her friends.
In trying to change my work life, I too had to deal with a “time suck” habit. I’ve known for years that my leisurely morning routine—reading the newspaper for hours over coffee and breakfast before sitting down at my keyboard—resulted in my accomplishing far too little in a workday. But like Rowe, like everyone else, I’ve been caught in a battle between reward and reason, a struggle in which our reward circuits have the advantage. Located primarily in our midbrain, reward circuits developed early in evolution to drive us to seek food, water and sleep and to reproduce. Likewise, fear and anxiety circuits, also extremely powerful motivators, evolved early so we’d try to escape danger. But our rational circuits, centered mainly in the prefrontal cortex (PFC), behind our foreheads, evolved much later. They help us look into the future and anticipate the consequences of our actions. We use our rational circuits to calculate risk, make complex decisions, exert self-control—and help us form positive habits. Every time a dieter is confronted with a double-cheese pizza, reward circuits shout “Yes!” while the rational brain shouts “No!” In my case, every time my alarm goes off at 5:30 in the morning, my PFC says “Get up, get up!” but my reward circuits say “Noooo! More sleep!”
The outcome of this battle can vary significantly from one person to another, depending on life experience and genes. That’s why it may take one person a few weeks to adopt or change a habit, while another person may need many months. The winner of the rational-versus-reward battle can vary within each of us because of the role stress plays in our efforts to form positive habits.
Stress and anxiety aren’t always bad, of course. Without them, we wouldn’t run from a bear. But stress—including, for example, the upheaval that results from loss and grief—shifts the balance of power in our brains by suppressing activity in the frontal lobes and boosting our craving for reward. When we’re under stress, we become fixated on relieving it, without thinking much about countervailing costs. “Once you see your life choices in terms of your desire to relieve tension,” says Duhigg, “many things make sense.”
Also weakening our ability to resist reward is a phenomenon called depletion. In 1998 psychologists led by Roy Baumeister, PhD, then at Case Western Reserve University, hypothesized that self-control could be exhausting for our rational brains. To find out if that was true, they conducted a series of experiments. In one they put hungry men and women in a room in which chocolate chip cookies had been baked, so the aroma filled the space. A plate of the cookies was on display, alongside a plate of radishes. The people were divided into two groups. One group was told to eat only cookies; the other group was told to eat only radishes. Five minutes later, both groups were asked to work on a geometric puzzle that was, unbeknownst to them, -unsolvable. The people who were told to eat the cookies, whose PFCs were rested because they hadn’t had to exert self-control, worked twice as long on the puzzle as the people who were told to eat the radishes. In other words, our supply of willpower can be depleted, making us more susceptible to the lure of reward and less able to escape a habit.