We've all been there. You're trying to introduce a morning run into your daily routine, or to put down your phone at night.
One week in, and things are looking good. Week two is a slippery slope... and as you look forward to the prosperity that week three may bring, your old ways start to creep through the cracks.
Habit formation is a tried and tested practice that involves time, dedication and a whole lot of effort. And it takes longer than you may think.
Habits are not something that we are consciously thinking about, and that's why they are difficult to change. Dr Laura Corbit
What goes into a new habit?
"Consider the basic paradigm of when a rat pushes a lever and gets rewarded," Dr Laura Corbit, Senior Lecturer in the School of Psychology at the University of Sydney, told the Huffington Post Australia.
"When a response leads to something reinforcing, that reinforcement strengthens an association between that situation and the tendency to perform that response."
"It's only over time or repetition that association becomes strong enough that it will be in control of our behaviour."
According to Dr Corbit, this is a vastly different system to deliberate, goal-directed behaviours.
"Habits are automatic, gradually developed and incrementally strengthened. They are not something that we are consciously thinking about, and that's why they are difficult to change."
Behind the 21-Day myth
In the 1950s, a cosmetic surgeon named Dr. Maxwell Marlz began documenting patterns of behaviour among his patients. After performing an operation, he found it would take the patient about 21 days to become used to their new face (following a facial reconstruction) or to adjust to a new situation (post amputation).
He wrote about his observations in the 1960s:
These, and many other commonly observed phenomena, tend to show that it requires a minimum of 21 days for an old mental image to dissolve and a new one to gel.
The message then started to spread -- in perhaps a misconstrued state.
"I don't think there's anything magic about 21 days. It all depends on different people and different factors -- what the reinforcer is will matter," Corbit said.
"And there's always going to be variability."
In a 2009 study, a team of psychology researchers from the University College London set out to provide answers.
96 people chose an eating, drinking or activity behaviour to carry out daily in the same context for 12 weeks. The researchers analysed their behaviours to determine how long it took each person to transition from starting a new habit to automatically doing it.
The result? On average, it took more than two months before a new behaviour became automatic. 66 days to be exact.
More importantly, the study showed that the length of time it takes to form a habit varied depending on behaviour, the person and their circumstance.
For Corbit, parameters aside, the take home message is to not expect immediate effect.
"It takes time to both develop a habit and to then change that behaviour once it is established."
"Because we know repetition is important, allow for that repetition and be consistent. If you try to do something once a week versus every single day, the speed at which you will adopt that new behaviour will be affected."
She recommends setting up a situation where you are more likely to perform your new habit over and over.
"That way, it can become more automatic," she said.
"Be realistic and don't expect a rapid change."