If you feel you consistently fail at your New Year's resolutions, you are not alone. Despite our good intentions, we're pretty poor at changing our own behaviour. We continue to smoke, eat or drink too much, and exercise too little, all of which affect our health and well-being.

In trying to change behaviour (including our own), we need to reduce resistance. You've likely heard some of the pitfalls of setting unspecific or unrealistic goals. Another contributor to resistance is when our intended action is not something we are personally motivated to do.

Psychological studies show we can overcome resistance by setting goals that tap into what we find meaningful and that reflect our needs.

Why New Year's resolutions fail

Why is it when we set a New Year's resolution our behaviour doesn't change, or it only changes for a limited time? There is a common obstacle that could underlie the failure of changing behaviour: resistance or more particularly inertia.

Inertia is a form of resistance where we can't motivate ourselves to perform a behaviour. We know what we need to do, the intention is there, we just don't do it.

One trap we can fall into is setting goals that aren't really our own – they're not personalised. Instead, we often set generic resolutions, such as to exercise more.

These may have been adopted from someone else's goal or may be based on what we feel we should change, as per social expectations or norms.

Adopting broad, generic goals may be a good starting point for change, but generic goals can also be conducive to resistance because they are low in personal relevance.

Setting goals that draw on personal motivations produces greater confidence in our ability to change and a greater sense of ownership over the process. These lead to larger and more lasting changes in behaviour.

What are your personal motivations?

The importance of ownership for personal motivation is captured nicely in what is known as the self-determination theory of motivation.

This places a high level of importance on doing what we find to be intrinsically motivating or working from what is inherently rewarding or satisfying. It's in contrast to extrinsic or external motivations which can create feelings of coercion when we follow goals imposed by invisible others.

If you choose to exercise more as your New Year's resolution because you think people will find you more attractive or because you feel guilty for not doing it, chances are you are working primarily from external sources of motivation.

If, on the other hand, you find exercise interesting and enjoyable or feel it expresses a personal value to be healthy, you are likely to be working from internal, personal motivations.

So, say your personal goal is to read 50 books in the year because you value knowledge. How do you put this into practice and make sure your resolution sticks?

How to put this into practice

One simple behaviour-change technique that can be applied to New Year's resolutions is self-persuasion. This essentially involves generating an argument for why you would like to change a certain behaviour.

Try to consider what is most salient and personally motivating for you and what a certain change could bring that you value. Perhaps you value knowledge and empathy, and you believe the more books you read about people's struggles, the greater understanding you will have of others.

Maybe exercising more, like getting involved in group sports, will help connect you with your friends. Or perhaps you enjoy alone time, and going for long hikes will give you more opportunities for quiet contemplation.

Although one of these examples may resonate with you, it's possible these aren't at all relevant to you. This is why it is important to examine what you find personally relevant.

The self-persuasion technique has been successfully applied in a variety of settings, including producing moderate, short-term reductions in smoking and work-related stress, and increases in tipping and intentions to help others.

Generating your own arguments is more effective in evoking change than reading multiple arguments generated by other people, even when the quality of the provided arguments is rated as being better than yours.

But when using the self-persuasion technique, remember less may be more. You are better off generating one to two reasons for your intended change than trying to generate a long list of arguments.

Also in studies that have tested this technique, participants have usually had to write their reasons down. This increased involvement may have also helped.

And then?

This is not the whole story of setting effective New Year's resolutions. Changing behaviour takes time and effort – particularly if you are trying to change a well-established habit.

During the change process, reflect often: consider what is and what isn't working, and how you could overcome obstacles that interfere with you achieving your goals.

This is where you can apply other goal-setting and behaviour-change techniques you may have learned about previously, such as understanding and altering what triggers and maintains your behaviour.

Implementation intentions are particularly helpful in setting goals and overcoming obstacles. This technique requires setting specific if-then plans for how you will respond in a particular situation — such as how you will ensure you get your daily dose of exercise if it is raining.

Five steps to setting personalised New Year's resolutions:

1.  Generate a broad resolution or goal as a starting point (exercise more)
2.  reflect on your motivation for this goal: is it driven by internal motivations and aligned with other aspects of your personality? If not, revisit the first step
3.  write down one or two reasons why the resolution is important for you
4. write down plans for achieving your goal, including if-then strategies
5. continue to review your progress and modify your personal goal as required.

The most beautifully constructed goals will be ineffective if they aren't personally relevant. Before you consider how to turn over your new leaf, it might be worth examining which leaf you want to turn over, and why.

Bernice Plant, Assistant Lecturer, Monash University This article is republished from The Conversation under a Creative Commons license. Read the original article.