If you have a teenager at home, it won’t come as any surprise that the rewards and punishments that used to work so effectively when they were kids can stop working when adolescence hits. This, of course, makes parenting a teen – and getting them to do what they’re told – immensely challenging.

Parents often blame themselves and wonder what they did wrong, but a study published in Nature Communications has shown that we could be fighting a losing battle – and teenage behaviour could be due to the way adolescents brains are wired.

The study shows that the teen years are a time of enormous change in the brain – including mass reorganisation. The brain’s grey matter, which has been growing since birth, starts to thin. This is most likely because the brain is shedding unnecessary nerve cell connections in order to make the brain work more efficiently. Sort of like defragging your computer.

The grey matter thins from the back to the front of the brain, with the prefrontal cortex – the part of the brain responsible for cognitive control and decision making – the last to be given a once-over.

Another aspect of the brain maturing is “upgrades” of structural and functional networks – making a change from more local connections to widespread global links between different parts of the brain.

Sounds exhausting, right? No wonder teenagers are so cranky.

One of the issues with this immature brain that’s still going through so many changes is its unsophisticated reward system, which hasn’t yet been complicated by a conservative, forward-planning ability to predict outcomes.

That’s why adolescence is a time of such great risk-taking, impulsivity and sensation-seeking. Teenagers have a legitimate inability to match their behaviour with the likely rewards or repercussions that could result.

The evidence

The study looked at the brains of people aged 13 to 20 by collecting data from magnetic resonance imaging (MRI), measuring the brain activity indirectly by tracking changes in blood flow as they played video games.

The participants were then offered high or low financial rewards or punishments for correctly sorting pictures of planets.

In adults or in younger children you could expect to see better performance when the reward is greater. The study showed that it was only participants aged 19 and 20 that tried harder for a bigger rewards.

Younger teens were less efficient at the task no matter what the stakes.

The study found that younger brains aren’t good at matching what they need to do with what they will gain or risk.

What can parents do?

So if offering greater rewards and punishments don’t work as a motivator to teens, what should parents be doing? Waiting until your teen is 19 or 20 is one answer.. In the meantime, try offering as much information as possible about something you want to reach an agreement on. Having more information can bring a teen around to your way of thinking, rather than bribing or punishing them.

It’s also important to recognise that risk-taking isn’t always a bad thing. Until now, your child has been under your wing and has had a lot of their decisions made for them. They are preparing to make their own way in the world, which is risky and exciting. They need to learn to take measured risks and understand the repercussions.

It can be a terrifying time for parents, but one that will reap rewards in the long run.