Millions of New Year's resolutions go sour within hours or days, because keeping them usually turns out to be tougher than we think, says nationally recognized motivational psychologist and University of Rochester Professor Edward Deci. His book, Why We Do What We Do, was published earlier this year by Grosset/Putnam.

"LOSE WEIGHT," we firmly resolve, and then find ourselves wolfing down a bowl of Chubby Hubby ice cream a few days later. We say we'll "QUIT SMOKING," but then a nicotine fit lures us toward the cigarette counter at the all-night convenience store. We vow we won't be slaves to plastic, but we're tempted by January sales to exceed our credit limits again. We say we'll get places on time, but soon find ourselves running late.

Here are five tips from Prof. Deci on breaking the cycle of broken resolutions:

1. ASK, DO I REALLY WANT THIS? "There's no sense in making a resolution unless it is something you really want for yourself, as opposed to something you think you ought to do, or something your parents, your partner, or your kids think you should do."

2. THINK ABOUT YOUR REASONS: "Sit back, be quiet, and ask yourself honestly, why would I want to do this? If you really believe you will enjoy life more and feel a sense of personal satisfaction if you pay your bills on time, or fit into a smaller size dress, then you may be ready to make the resolution."

3. PREPARE TO SUFFER: "There is a reason for each of our bad habits. You may smoke because it helps you feel calm in social situations. You may binge on pizza because you're feeling anxious. Before you make a resolution, ask if it's important enough that you're willing to endure the anxiety and discomfort you'll feel when you follow through on your change."

4. GET HELP: "Some changes that people want to make may be too hard to accomplish alone. Quitting smoking and losing weight are good examples. Your friends and family can be a source of support. And you may need to enroll in a smoking cessation program, join a program like Weight Watchers, or get professional help to stay on target."

5. HANG IN THERE: "If you really want to change, then go for it. But don't be surprised if you fail a few times before you succeed, because changing personal behavior is hard work. If you fall down, try to understand what got in the way of your success, and then try again."