Stretch, Sleep, Repeat: The Neuroscience of Habits

Our brains play a powerful adaptive role in the formation of habits. Here’s the science and how to use it to your advantage.

Becoming a London taxi driver is no walk in the park. To be unleashed as a fully-fledged cabby, drivers must first pass a notoriously difficult test known as The Knowledge. It requires memorisation of epic proportions.

Candidates must learn routes that span more than 60,000 streets of London, along with the more than 100,000 places of note that line them. Preparation for the test typically takes the same time as a bachelor’s degree. And unsurprisingly, many try and fail.

Those that eventually gain The Knowledge are among the most highly regarded taxi drivers in the world. Their brains hold a more effective driver’s map of London than any GPS system. They are unique in their trade.

In fact, it’s this uniqueness in the London cabby which first attracted researchers from University College London. You see, the researchers had a hunch that something different was going on in their brains. And they were right.

London taxi drivers were found to have larger posterior hippocampi – a part of the brain associated with navigation and memory – than control groups who didn’t drive taxis.

This wasn’t just a phenomenon related to The Knowledge test either. The hippocampus also increased in size as they gained experience, years into their careers as London cabbies. Then, after they retired, the hippocampus reduced in size.

This now famous study is a useful illustration of an important point. When we stretch and repeat, our brains change to accommodate our new habits – and eventually automate them.

In short, it is the task of our brains to make our lives easier. Stretching and repeating is the fuel that permits that adjustment. It’s the fuel that makes the navigation-supporting part of a London cabby’s brain larger, and that eventually makes initially straining navigation feel automatic. It’s a reminder that what feels painful at first will eventually feel like a walk in the park.

And thankfully, this adjustment is not limited to London cabbies. We can all take advantage of it.

The Magic of Neuroplasticity

All our behaviours and choices ask an important question of our brain: How can I make this easier the next time around? At the heart of the answer is a neurological phenomenon known as neuroplasticity.

Neuroplasticity refers to the ability of the brain to change throughout our lives. Researchers are taking a growing interest in one of its sub-fields, activity-dependent plasticity: the study of how cognitive functions and personal experiences change our brains. It’s a field that provides some important lessons on how our habits – new or old – alter the brain, and how our brain helps us along the way.

As we have already seen, navigating around the labyrinth streets of London leaves cabbies with larger posterior hippocampi than the average person (and even the average bus driver). But studies are increasingly showing how other activities provoke adaptation in relevant brain regions. One study found that the cerebellum – a part of the brain associated with balance and coordination – is larger in musicians than non-musicians. Numerous studies have shown that regular meditation can increase gray matter and reduce amygdala activity.

These individuals are not born this way. Their brains adapt when each of the relevant regions get exercised. Like exerting our muscles at the gym, repeatedly working a region of the brain leads to strain and subsequent growth.

As we repeat a pattern of activity, such as a learning task, we also experience long-term potentiation (LTP). Our brain transmits messages between neurons via chemical structures known as synapses. And over time, more transmissions between neurons lead to a strengthening of our synapse network and a long-term increase in transmissions between neurons. This increased connectivity plays a key role in habit formation.

Quality Reps > Time

Why does all this matter?

This neurological jargon is really just the science behind what we already know. Persistent, stretching repetition facilitates learning. But the beauty of the neuroscience is that it tells us that the brain is on our side, working for us – not, as it may feel sometimes, working against us.

The core insight is that repetition eventually makes habits and skills feel automatic. But as James Clear points out in his bestseller Atomic Habits, the question should always be “how many repetitions are required to make a behaviour automatic?” and not how much time.1

Repetition, and not time, is what makes habits stick. If we focus on time, we risk undermining the quality of the behaviour we are repeating and therefore missing out on the neurological support from our brains.

But these neurological changes don’t happen by magic. They require purposeful change in the first place. And that may require some other choices.

How to Make Habits Automatic

With that in mind, here are four important practical ideas on how to get these habit reps done.

#1: Prime your environment. Create an environmental trigger for the habit. For example, as I wrote a few months back, arriving back home and getting changed into my gym stuff is my trigger for going to the gym. Once I’ve done that, I know I’ve initiated the habit loop and avoided the dreaded YouTube rabbit hole. It’s much easier to do something when you take a symbolic first step in your environment.

#2: Consistently show up. Don’t underestimate the power of just showing up and starting. You don’t need to feel like doing something to do it. I don’t feel like writing for this blog every Saturday morning, but the simple action of dragging myself to the café in which I write and making a start will almost always deliver a result. Adopt this approach and you beat the biggest obstacle to forming a positive habit: starting.

#3: Package habits with a reward. Link the behaviour with a subsequent reward. Studies show that we are more likely to stick with a habit if we package it with a near-term reward. Rewards too distant can lead to an effect known as temporal discounting, where we devalue the reward because it is so far away. An easy way to effectively package a habit with a reward is to stack on a pleasurable habit after the desired habit. For example, “after I complete the blog post, I will watch an episode of my favourite series on Netflix.”

#4: Don’t beat yourself up. If you miss a repetition, don’t be too hard on yourself, but get back on it for the next repetition. Research indicates that those who don’t fully forgive themselves are actually more likely to miss a repetition again. This may seem counterintuitive but it’s worth keeping in mind when seeking to maintain the momentum behind a new habit.


  • Our ability to learn and form habits is supported by changes in our brain, a phenomenon known as neuroplasticity.
  • Through stretching repetition, our brain adapts to help make behaviours and skills feel automatic.
  • Stretching repetition – and not time – is a better measuring stick for the point at which habits will stick.
  • To help get this repetition in, we should use environmental triggers, consistently show up, package habits with a reward, and avoid beating ourselves up if we miss a rep.


1 One chapter in Atomic Habits, which featured a couple of the aforementioned studies, served up a hefty dose of inspiration for this blog post. I recommend this book to anyone interested in the science of habits.

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