The holiday cookies are all eaten and the last champagne toast has been downed. It’s time for a new year and a new you, right? Surveys suggest that about half of us will make New Year’s resolutions, most of which will have to do with exercising more, eating less, and permanently snuffing out cigarettes. Unfortunately, some old acquaintances aren’t too soon forgotten, and our habits tend to follow us into the New Year, for better or for worse.

“People recognize intuitively how much of their lives are habits,” says Charles Duhigg, a New York Times reporter and author of the bestselling book The Power of Habit. He cites a Duke University study that found that 40 to 45 percent of people’s daily actions are habits or unconscious decisions. For the most part, we should be thankful that our brains have a highly functional autopilot mechanism. There’s enough in life to worry about without having to give our full attention to tying our shoelaces or driving to work. “The problem is when that same automatic tendency takes over something we do care about, like what we’re eating, or how often we’re exercising, or how we spend our money,” notes Duhigg.

For centuries, everyone from Artistotle to Oprah has talked about changing habits, and New Year’s in particular is a time when we focus on new beginnings and fresh starts. For many people, that means trying to ditch some persistent…