«Our brains love habit»

What exactly has my brain got against me changing my habits? Do human beings really possess free will? Renowned neuroscientist and philosopher Gerhard Roth provides some answers.

Interview: Ruth Jahn

When was the last time you did something by force of habit and regretted it?
Prof. Gerhard Roth: Recently I was so lost in thought that I ended up going to a place I used to live in for two decades instead of going home.

Routines govern our lives – from brewing our morning cup of coffee and deciding how to get to work to brushing our teeth before going to bed. Why?
Over 80% of our actions take place automatically without us having to even think about it. Our brains strive to turn everything into a routine because thinking is time-consuming! Routines help our brain conserve energy and minimise risks. This makes sense from a neurobiological perspective, and it’s even essential for survival, but it can have adverse effects on us – for example, when we develop a bad habit.

Why do we find it so difficult to change established habits?
Before we’re born and during the first few years of our lives, our brains are extremely malleable. This malleability has declined dramatically by the time puberty hits. Our brains increasingly begin to think: enough testing! Changing all the time is too much hard work for me now. When we establish habits our brain rewards us with its own home-produced opioids, which are really addictive. The older we get, the more difficult we find it to change our ways.

Which part of the brain controls habits?
When we learn something for the very first time, this is controlled by our cerebral cortex. Once we’ve repeated this action multiple times, it becomes routine. The relevant information slips into our basal ganglia, deep inside the brain. Here it is stored as fixed processes than can no longer be deleted. This is why it’s extremely difficult to try and replace an old habit with a new one.

So our brains basically undermine us when we want to change our behaviour?
Exactly. Our brains protest. It might be capable of learning and relearning things, but relearning is much more difficult.

And if I’m not put off by this, what can I do to encourage my brain to relearn something?
Relearning requires practice and motivation. Like a piano student rehearsing a Beethoven sonata: at first it sounds amateurish, but with regular practice and enough motivation it’ll start to sound OK after eight weeks.

What are the best ways to motivate yourself?
Speaking as a neuroscientist I would say very few factors really have a fundamental impact on our behaviour. Psychological effort is required in addition to repetition and the prospect of reward. It’s especially helpful if the effort is connected to a person we have a strong connection with. The last incentive for changing our behaviour is always an external factor!

Can you give us an example?
Let’s say a woman doesn’t want her husband to leave his dirty laundry lying around any more. Her best chance of achieving this is threatening to pack her bags and leave if he doesn’t. Fear of punishment is a powerful incentive. She should also remind him about his dirty socks as often as possible because he needs to familiarise himself with the routine. Threat of punishment should always be followed by reward – whatever that may be!

You can motivate yourself without putting yourself under pressure!
Yes, to a limited extent. In this case, the reward on offer must be more enticing than the benefits of your work avoidance strategy.

Does free will even exist?
Theoretically speaking, we’re not entirely free to make our own choices. Once we’ve established habits, we no longer question whether our actions are good and what the consequences are. This eases the pressure on us, because we no longer have to think hard about our every action. After all, a certain amount of stability in our thoughts and actions makes life easier as it makes our behaviour easier for others to understand.


Gerhard Roth has a PhD in philosophy and biology and is Professor of Behavioural Psychology and Developmental Neurobiology at the University of Bremen. He also runs Roth GmbH – Applied Neuroscience and the Roth Institute, both based in Bremen.

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