Old habits die hard, and that’s particularly true of bad habits.
New Year’s resolutions, derided though they often are, present a big opportunity for self-improvement, according to research on human behavior. On New Year’s, we look back on past failures to change and feel an uncommon surge of optimism. We rationalize that it was “the old me” who failed to change, but this year will be different. A full 40 percent of Americans make New Year’s resolutions, and fortunately for them, social science has some insights into how to break a bad habit — or start a good one.