Today's guest post is written by David Maxfield, the three-time New York Times bestselling author of Influencer, Change Anything, and Crucial Accountability. For more than 30 years, he has served as an expert in change management, interpersonal communication and corporate training. He is an acclaimed keynote speaker, consultant and vice president of research at VitalSmarts, an innovator in corporate training and organizational performance. David blogs regularly at Welcome and thanks for contributing this piece to PsySociety, David!

It’s the middle of January. Have you given up on your New Year’s resolutions yet?

When we polled 1,800 people to see what we can learn about making and keeping resolutions, we found that half of all resolution makers give up on their goals by the end of January.1, 2 Moreover, three out of the four people who do make it to February throw in the towel by the end of March.

And let's not ignore that giving up on these resolutions is costly. Of course, people’s success and self-esteem took hits. But we were surprised by the financial impact of a failed resolution: Seven out of ten said their failure cost them more than $1,000. And these costs were compounded, because more than three out of four said they’d made and then given up on the exact same resolution for more than five years!

So, what goes wrong? Why do so many of us fail at our resolutions? I’ll describe three challenges and suggest strategies we can use to overcome them.

1. We fall into the Willpower Trap. We believe that willpower alone will be enough to drive and sustain change.

We fall into this trap because we fail to see the influences that are lined up against us. The old adage is, “fish discover water last.” We are the fish, and we live in a sea of influences. Take overeating, for example. Research shows that our friends make us fat3, dining with others stimulates overeating4, and the size of our plate can cause us to gorge4. There are dozens of these invisible influences around us all the time, and, if they aren’t addressed, they will overwhelm our willpower.

The solution to the Willpower Trap is to educate our eyes. Our research uncovered a simple model that identifies six different sources of influence that both motivate and enable us to behave in certain ways. Those sources are: Personal Will and Skill; Social Encouragement and Support; and Structural Incentives and Tools.

Let’s use this model to see why I might be struggling with my weight loss resolution. Personal: I crave fried foods, and I don’t know any low-cal recipes. Social: My daughter wants me to eat the pies she bakes, and my boss takes me to lunch. Structural: I get rewarded for cleaning my plate, and my plates are the size of manhole covers. It’s common to discover obstacles in all six sources—obstacles we didn’t notice and therefore didn’t counter act.

2. We over-rely on silver bullet solutions. We put our faith in one or two strategies for change when success actually demands five or six strategies in combination.

Our research shows that only five percent of people use four or more sources of influence to tackle their resolutions. And this tiny minority is ten times more successful than the rest5. Here is what a six-source plan might look like:

Will: Have a “mission moment” talk over breakfast every morning. Spend two minutes reminding myself and others why I want to keep to my diet and exercise plan.

Skill: Read up or take a class on healthy food preparation.

Encouragement: Ask my wife to give me a subtle reminder when she sees struggling with my diet.

Support: Ask my family to avoid buying or preparing fatty, salty, or sugary foods. Ask my daughter to walk with me every evening.

Incentives: Weigh-in every Friday morning and put $5 at stake. If I lose two pounds, I get the cash; if I haven’t, I have to cut it into pieces.

Tools: Purchase new running shoes, cookbooks, map of local walking trails, an eating and exercise journal, or display a graph for tracking my weight loss.

3. We treat setbacks as character flaws. When we encounter reversals, we blame ourselves.

As a result, we feel lousy and depressed. Our mood, which should be one of our best motivators, becomes an impediment. Often, we let ourselves off the hook, or even go on an unhealthy binge to try to bring our mood back up.

Instead of judging ourselves, we should evaluate our actions the way a scientist would. Look at your setbacks and become curious. Turn bad days into good data. Use your setbacks to pinpoint weaknesses in your plan and improve them.

Identify the crucial moments—the times, places, and circumstances—that were associated with your setback. Then focus your planning on those crucial moments. Maybe you kept to your diet all day but then gave in to a bag of chips while you watched a TV show before bed. Focus your efforts on that three-hour period of time. Develop a plan to prevent it in the future. Remember, setbacks don’t reflect on the person, they reflect on the plan. Keep your plan alive and evolving. Tackle one setback at a time until your plan succeeds.

Our research shows that if you stick to this science of behavior change, you’ll increase your chances of success in 2014 tenfold5.

This post is the last in a series of pieces at PsySociety on the psychology of setting - and achieving! - your New Year's Resolutions. You can see the other posts on how to set good resolutions, how to pursue them, and whether or not it's helpful to broadcast them on social media by clicking the links in the text. Best of luck, everyone!

1. Kerry Patterson, Joseph Grenny, David Maxfield, Ron McMillan, and Al Switzler. Influencer: The New Science of Leading Change. McGraw Hill, 2013.

2. Kerry Patterson, Joseph Grenny, David Maxfield, Ron McMillan, and Al Switzler. Change Anything: The New Science of Personal Success. Business Plus, 2012.

3. Nicholas A. Christakis and James H. Fowler. Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives -- How Your Friends' Friends' Friends Affect Everything You Feel, Think, and Do. Back Bay Books, 2011.

4. Brian Wansink. Mindless Eating: Why We Eat More Than We Think. Bantam, 2010.

5. Joseph Grenny, David Maxfield, and Andrew Shimberg. How to Have Influence. MIT Sloan Management Review, October, 2008.

Featured image available through Creative Commons via SeniorLiving