Is your brain sabotaging your New Year’s resolutions?

At the start of a new year, many of us take the opportunity to start taking better care of our health, whether it’s to increase our exercise, eat healthier, start having regular check-ups, or all of the above. We also might start wondering what happened this time last year, when these very same good intentions fell by the wayside.

Why is it so hard to keep our new year’s resolutions, particularly when it comes to health? The field of behavioural science may hold the key to understanding why our very best intentions can be so easily swayed by our cognitive biases.

What are cognitive biases?

Cognitive biases are mental shortcuts that the human brain has developed over time, sub-consciously affecting our decision-making processes. They can often result in us behaving in certain ways that are irrational and at odds with our motivations and desires.

There have been over 180 distinct cognitive biases identified by behavioural scientists to date! Let’s take a look at a few key ones. You may even recognise some of these in your own behaviour.

The Licensing Effect

Similar to how our bodies are programmed to maintain homeostasis through regulation of body temperature, our minds also tend to seek a balance between virtuous and self-indulgent behaviour.

Raise your hand if you’ve ever caught yourself thinking along the lines of “gosh I am so great for getting off the couch and going for that run. I really deserve that piece of chocolate cake for dessert tonight!”. It’s not hard to see how our new healthy habits can be derailed by this line of thinking.

The good news is the licensing effect can be used to our advantage, so long as the reward is appropriate and in proportion to the behaviour we have performed. Try setting yourself an achievable target such as “I will go for a 30-minute walk on at least 5 days this week” and reward yourself with a non-food-related treat, such as buying that new book you’ve been wanting, or having a manicure. Over time, the new behaviour of regularly walking will become associated with the pleasure of the reward, making it a habit in its own right!

Social Proof

Like it or not, humans are fundamentally conformist creatures. We like to be doing what other people are doing. For most people, going against the tide is inherently uncomfortable. Jumping on the bandwagon and FOMO (fear of missing out) are familiar concepts which describe our underlying desire to conform.

What does this mean for health? Think about how much willpower it takes to decline an invitation to have a drink with your friends at the pub because you planned to go to the gym. Similarly, at a dinner party it can be very difficult to turn down dessert if everyone else is having it.

Surrounding yourself with like-minded, supportive people can greatly improve your chances at maintaining new healthy behaviours. This certainly doesn’t mean you should ditch all your friends – rather, aim to build social connections in conjunction with your new habits, such as join a walking group or sporting team, have a regular gym buddy or even an online social forum where you can help keep each other accountable and on course.


Our decisions and behaviours can be influenced by the positive or negative connotations of the available options. A lot of people struggle with exercise because, well, it can be uncomfortable and painful exerting all that energy, especially if we are not used to it!

A recent study by Berman et al (2019) found that ‘cognitive reappraisal’ was effective in influencing participants’ interpretation of muscle pain during exercise. Participants who listened to a voice recording describing muscle pain in a positive light (as a sign of muscle-building) were less likely rate their muscle pain as unpleasant (during a subsequent bench-pressing exercise) compared to those who listened to a voice recording framing muscle pain as a potential sign of injury.

We can apply this ourselves when looking to make changes to our exercise habits. A good start is to choose an activity that you will enjoy – not even the best of us can create a habit if we are hating every minute of it!

Secondly, try reframing in your mind how you are perceiving the muscle burn during exercise. Thinking about how the pain is a sign of building muscle and improving your health could be helpful in maintaining persistence.

Temporal Discounting and Projection Bias

Temporal discounting refers to the fact that we humans are hard-wired to prefer short-term gratification over long-term rewards. It is related to the projection bias in that we are also notoriously bad at predicting how our future selves will feel about something.

We see this in effect when we elect not to put extra money into our retirement savings and instead choose to buy a new car or take that family holiday. It also explains why it’s ill-advised to go grocery shopping when we are hungry – at that point in time, we cannot envisage ourselves not being hungry and we tend to buy too much, or we buy less-healthy foods to satisfy our hunger.

With regards to our long-term health, many of us simply can’t imagine our future self who is now feeling the effects of a lifetime of inactivity and poor diet. Sure, we know we should look after ourselves now to reduce the risk of developing diabetes, cardiovascular disease and other chronic conditions, but similar to saving for retirement, that seems a long way off in the future and this tendency for us to live in the ‘now’ is what drives a lot of our decision-making.

So what now?

It’s important to know that all these cognitive biases are very common – we all experience them to some extent. While some cognitive biases can be good, allowing us to take mental shortcuts and guide us to decisions where we are uncertain, there are also some cognitive biases (like the ones above) that can result in poor choices.

Simply understanding how they affect us can be beneficial for our health journey, as we can more readily recognise situations where cognitive biases are influencing our decisions, and we can be more proactive in making the right choice for our health.