A resolution can make you resolute:

Anyone doubting that New Year's resolutions can improve behavior should resolve to read John C. Norcross' psychological studies.

His works provide evidence that resolutions have helped a good number of people lose weight, adopt exercise, quit smoking, improve relationships and reduce alcohol consumption or debt.

Still, the University of Scranton psychologist said resolutions pose a glass-half-full versus glass-half-empty scenario, even though he prefers the former.

After six months, his studies conclude, up to 46 percent of people continue abiding by their resolutions, while only 4 percent claim success who stated a desire to change behavior without resolving to make the change.

Dr. Norcross described the difference as "a concerted effort to change versus the clink of a champagne glass."

"Four percent versus 40 to 46 percent -- in that case it looks awfully good at a single attempt at a life change," he said.

The results could be overestimated, because study participants self-reported successes and failures, and repeated phone calls from researchers to document results might have provided incentive to abide by the resolution.

After just one week, 75 percent of resolvers typically stick to their guns, but after one year the number drops precipitously to less than 20 percent. Still, considering the change of life-threatening behavior, the 15- to 20-percent success rate equals significant improvements in human health and habits. Resolutions that fail often are adopted the following year, with success often taking three to five years, he said.

In a previous study published in the Journal of Clinical Psychology, Dr. Norcross and team said "at least 40 percent of adults make one or more resolutions each year" and two-thirds of the pledges "concern life-threatening health behaviors -- tobacco smoking, obesity and inactivity. ..."

"Contrary to widespread public opinion, a considerable proportion of New Year's resolvers do in fact succeed, at least in the short run," it states, refuting the longstanding contention that "resolutions never succeed."

Dr. Norcross said he's proof that resolutions work. Last year, he resolved to exercise at least four times a week and the practice continues, despite a busy travel schedule. This year, he said, he will resolve to refrain from eating dessert 90 percent of the time.

That reflects a key characteristic of a successful resolution: Make it reasonable. For him, he said, a complete dessert ban would be a ticket to failure.

"Big goals beget big changes," Dr. Norcross said. "Unrealistic goals beget resigned resolvers."

Five serious studies have been done on the success rate of resolutions, and Dr. Norcross and team have done three of them. His extensive work on the psychology of resolutions has produced these helpful tips:

• Make realistic, attainable goals before Jan. 1, along with a plan of action. Publicly declare your resolution.

• During January, cultivate social support or a buddy system. Track progress by charting behavior. Self-monitoring heightens the probability of keeping the resolution.

• Reward success with a healthy treat or a reward established in advance with a loved one.

• Set up your environment to help rather than hinder your resolution. "If you are limiting the sweets, don't hang out in a bakery," one of Dr. Norcross' essays states.

• Expect slip-ups but avoid falls. Missing one exercise session should not put an end to the entire exercise regimen. Use slip-ups to strengthen resolve.

• Avoid self-blame, which is a prime predictor of failure.

A resolution, Dr. Norcross said, is a marathon, not a 100-yard dash. Negativity is bad. A positive attitude is recommended.