The psychology of New Year's resolutions (and how to get better at keeping them)

Habits, whether good or bad, can be hard to break. Just how hard is a question that self-help gurus and armchair scientists have taken on enthusiastically in recent decades: How long does it take to break an old habit (or form a new one)? 

“I know there’s been some unusual durations thrown around, that you need 21 days or eight weeks or six months to break a habit,” says John Mahoney, a psychologist and lecturer at ACU’s School of Behavioural and Health Sciences. “I don’t really know where all these numbers come from but I’d like to see the science behind them.”  

The duration that gets bandied about most often – 21 days – originates from a 60-year-old book by a plastic surgeon who observed his patients adjusting to their new faces after three weeks. And yet, the main evidence-based time frame for habit formation shows it varies widely: a 2009 study found it could take anywhere from 18 days to 36 weeks. 

Time, it seems, is probably not of the essence when it comes to behaviour change.  

There is a time of year, however, when we’re most likely to set ourselves lofty new goals in the hope we can improve our lives. 

The New Year’s resolution is an unstoppable force. 

Every year, in early January, millions of people resolve to change their behaviour in order to lose weight, get fit, save money or spend more time with friends and family.   

But for most people, these self-set promises fall by the wayside within weeks, leaving the so-called ‘resolutioners’ disheartened and despondent. 

So, what is it about the turn of the year that makes people want to shift their behaviour in some way?

“It’s the old ‘fresh start’, isn’t it?” Dr Mahoney says. “We’re drawn to the attraction of new beginnings, and we appreciate the fact that we make mistakes and that we’re fallible. The year in review might highlight some of the mistakes and errors we’ve made and prompt us to do something different.”  

There’s another thing about the New Year that makes the idea of behaviour change so attractive: the time that precedes it.  

As the year nears its end, our healthier habits tend to make way for indulgence. We emerge from the ‘silly season’ with a bulging belly, a pounding head and a sense that we’ve let ourselves go.  

“It’s no coincidence that gym membership increases around January,” says Dr Mahoney, whose research has explored physical activity as a vehicle for positive development. 

“After all the eating and drinking and festivities of Christmas, you know you’ve put on extra weight or been less active, so you see that as something you’d like to change.” 

Christmas also empties our pockets, with loose spending on gifts and festive decadence, hence the prominence of New Year’s resolutions to be more frugal. 

Time spent with loved ones over the holiday period can highlight the salience of close relationships, which can prompt a goal to make more time for family. 

It should therefore be no surprise that things like health, fitness, relationships and personal finance tend to top the list of New Year’s resolutions. 

But why do so many of us fail to make them stick?  

Goals and intentions 

In setting a resolution to change our behaviour, we’re taking an essential first step in forming a positive new habit. 

“In psych terms or performance terms, a New Year’s resolution is simply a goal,” Dr Mahoney says. 

“Whether the resolution is, ‘I want to get healthier’, ‘I want to be more frugal’ or ‘I want to be a better son’, as vague as that goal is, it’s still a goal.” 

Setting goals isn’t a bad thing, Dr Mahoney adds, but it’s also not a very good predictor of future behaviour. 

The goal acts as a starter engine; it gets the behaviour change vehicle going. But the vehicle needs fuel to keep it moving to its desired destination, and many of us go no further than turning over the engine.  

The proverbial fuel is the missing link between setting a goal and attaining it. This is often referred to in the literature as ‘implementation intention’ or ‘intention formation’. 

“An intention formation is an action plan that we have about when, where and how we’re going to implement a particular behaviour, so it’s linking the goal to the actual doing,” Dr Mahoney says.  

“If your New Year’s resolution is, ‘I'm going to get fitter this year’, the people who set that goal and stop there, they’ll likely drop out of exercise eventually. But those who go to the next step of putting together an action plan that they consistently strive for, they’re more like to reach their goal.”  

When it comes to things like exercise, that means being quite specific — not necessarily of your desired outcome, but of the actions you need to take to get there. 

“You might say, ‘Okay, I'm going to do three bouts of exercise a week, and I’ll do two of those at the gym and do these types of activities, and the third bout will be a swim or a long walk’,” Dr Mahoney says. 

“By being quite deliberate in the planning of your new behaviour, it makes the goal more tangible, and the ‘when, where and how’ component of implementation intention makes the behaviour more actionable, so we know exactly what we’re going to do and when, where and how we’re going to do it.” 

Capability, opportunity, motivation 

In the modern era, behavioural scientists have put forward several strong theories around how best to form new habits. 

Among the most compelling is the work of Susan Michie, a British psychologist who posits that achieving behaviour change comes down to three aspects: capability, opportunity and motivation (COM).

Her ‘Behaviour Change Wheel’, also known as the COM-B model, is so effective that the British government employed her to develop behaviour change strategies for reducing the transmission of COVID-19.

The model defines capability as “the individual’s psychological and physical capacity to engage in the activity concerned”; opportunity refers to factors outside the individual’s control that make the desired behaviour possible; and motivation describes the cognitive processes that energise and direct behaviour: goals, decision-making, habitual practices and emotional responses. 

“When you’ve made a resolution to change your behaviour, ideally you need to get all three of those things – capability, opportunity and motivation – ticking over,” Dr Mahoney says. 

“You need to set yourself a goal that you’re capable of achieving, so you feel you can do whatever it is you want and need to do. You have to be sure you've got the opportunity in terms of ease and time and openness to it. And you need to have the drive and the energy to see it through in the long-term.

“Unless you’re consistently working on those three factors, and unless you're forming really strong implementation intentions, there’s virtually no chance you’ll achieve your goals.” 

Resolutions that stick

So, we’ve established that there’s probably no harm in setting New Year’s resolutions; they can work if you have a plan and take action in the days, weeks and months after 1 January.  

But how do we set ourselves goals that stick?

Dr Mahoney suggests that, contrary to the spurious advice of many self-help gurus, a specific goal is not necessarily a pathway to success. 

“In a lot of walks of life, there’s evidence to suggest the opposite, particularly for individuals who are just starting out with a new behaviour change,” he says. 

“For those people, it’s often better to have a very vague goal, because the expectation is a lot more gaseous and flexible.” 

Setting a goal to run five kilometres in 25 minutes, for example, is very stringent. If you have an unrealistic expectation of how quickly and easily that’s going to happen, and it doesn’t eventuate, you’ll risk dropping away. 

A less explicit goal can be much easier to satisfy. 

“If you have a vague goal of getting healthier and you run around the block once or twice a week, you’re attending to your goal,” Dr Mahoney says. 

“You have a much greater catalogue of behaviours that allow you to address that vague goal, which ultimately means you’re less likely to pack it in.” 

However, as mentioned earlier, while aiming for specific outcomes can be detrimental, taking specific action is advisable. 

“You can be a bit more direct in terms of the ‘what, where and when’ implementation intention … But if you’re starting something out and your capability is low, your opportunity is limited and your motivation is up and down, it’s much better to have very vague goal around what you want to achieve.” 

And it should go without saying that you don’t need to wait until the New Year; goals are achievable at any time.   

“There’s no right or wrong time to set these things, but trying to change your behaviour in December and January is probably a little harder than other times of year because your habits are all out of whack,” Dr Mahoney says. 

“Once you’re back into the swing of things, you can more easily set yourself good goals, put together a solid plan of action, and start working on those capabilities, opportunities and motivations, so you maximise your chances of success.”

Dr John Mahoney is a lecturer in Exercise and Sports Psychology at ACU’s Brisbane Campus. His research focuses on enhancing the performance of individuals and groups, and on the conditions that leaders provide and how that influences the development, functioning and wellbeing of those they lead.

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