Theoretically, if you make a resolution, then it shows you are determined to make that change a part of your life.
In my experience, if it's on your New Years Resolution list, then it's not going to happen:
What Actually Happens
Gain 20-30 pounds.
Quit biting nails!
Chew off entire finger.
Be nicer to your fellow man!
Engage in an act of road rage so severe, it makes the national evening news.
I thought about making some Reverse Resolutions this year. You know, instead of resolving to lose weight, I'll resolve to gain weight. Then, I'll feel unnaturally compelled to train for a marathon and adopt a vegan diet.
However, I am not prepared to take that sort of risk. Knowing my luck, I would finally manage to keep a New Years Resolution. By the end of 2012, I'd look like a porpoise. So this year, I am making zero resolutions. Happy New Year!