The differences in a developing brain: why 12 is too young for the age of criminal responsibility

Australian states and territories have agreed to raise the age of criminal responsibility from 10 to 12 years old. 

But 12 is still out of step with many other developed nations and goes against the United Nations’ Committee on the Rights of the Child and Australian Human Rights Commission, both of which recommend increasing the age to 14. 

Australian Medical Association President Dr Omar Khorshid has said raising the age to 12 falls “well short of what is needed” and ignores medical, legal and social advice on the real harm of the current laws. 

The law disproportionately affects Indigenous children who are some of the most incarcerated youths in the world, with experts arguing the difference between a 10, 12 and 14-year-olds’ brain is stark.

How does the brain change in four years? 

The part of the brain responsible for culpability — the prefrontal cortex — ramps up development from around the age of eight, when kids become able to plan ahead and factor future consequences into their decisions. During puberty, which generally hits between the ages of nine and 13, brains go through a growth spurt, with kids developing better reasoning abilities, identity and consciousness, bringing the ability to appreciate what other people are thinking and feeling.

But as neuropsychologist and associate professor at Melbourne University’s Centre for Youth Mental Health Warrick Brewer tells Crikey, these developments don’t happen all at once. During the first trimester of brain development in puberty, he said, kids still have a basic understand of morality.

“Across early puberty, it’s pretty normal for kids to be black and white in their thinking so they’re less flexible about what’s right and wrong,” he said. ​​

“They tend to be more focused on their own feelings rather than having the resources to regulate the impact of their behaviour based on an understanding of other people’s feelings and state.”

Research shows as their morality compass becomes more nuanced, kids between the ages of 10 and 14 become more susceptible to peer pressure. It’s rare for kids aged 10-14 to commit serious crimes, with young kids more likely to have property damage offences, while those aged 15-17 are more likely to have theft, drug and unlawful entry offences.

Those who end up in the justice system aged under 14 are more likely to have an undiagnosed disability or be experiencing trauma.

Along with physical and mental development comes impulsivity and an increased likelihood of engaging in risky behaviour, Brewer said, with dopamine activity increasing teens’ sensitivity to reward and making them more likely to seek out thrilling behaviour. The brain doesn’t stop developing until around the age of 25, though parts of the brain reach maturation at 18.

What compels criminal behaviour? 

Across the 2020 June quarter, there were nearly 800 children in youth detention in Australia. Just 9% were girls, and 48% of all kids in youth detention were Aboriginal or Torres Strait Islander children. Indigenous youth are 17 times more likely to end up in youth detention. The Northern Territory has the highest number of incarcerated kids in Australia. 

Brewer says problematic behaviour is a result of underlying emotional distress, and acting out is a response for teens who are being overwhelmed by “powerful, natural, healthy feelings” who haven’t developed or learned the tools to cope with those feelings. 

“Through no fault of their own, they are externalising signs of that distress and being blamed for the underlying unmet need,” he said. 

“It’s like not feeding an infant, then punishing him when he starts acting up to show his hunger.” 

Most kids who end up in youth detention centres are disadvantaged, with experience of ongoing social, family or educational adversity, and a history of traumatic life events. 

University of Sydney associate professor of psychology Paul Rhodes tells Crikey while kids need to learn about accountability, different approaches were necessary. 

“Their troubles are all tied up in family issues and trauma and poverty, marginalisation, racism … and the idea of throwing jail at the complex problem is cruel,” he said. 

Long term family therapy is one solution, he said, helping to set and enforce boundaries and build attachments with the community to make sure kids are engaged and have structure. 

What happens to kids in the system? 

Locking kids up, unsurprisingly, doesn’t heal their histories of trauma. The younger a child is when they encounter the criminal justice system, the more likely they are to reoffend. 

A 2017 royal commission into the protection and detention of children in the Northern Territory found kids were subject to verbal abuse and denied access to toilets, water and food and were dared or bribed to hurt each other, with detention causing lasting psychological trauma. One Brisbane-based study found 75% of boys and 90% of girls in youth detention had mental health challenges indicative of trauma.

The government is seeking to reduce the rate of Aboriginal and Torres Strait Islander kids in detention by 30 per cent by 2031, though incarceration rates haven’t dropped in recent years. 

A spokesperson for The National Aboriginal and Torres Strait Islander Legal Service said raising the age of criminal responsibility to 12 instead of 14 was irresponsible. 

“The medical evidence is clear – no child belongs in prison, but 14 years old is the absolute youngest age a child should be subjected to the criminal legal system,” they said. 

“​​If governments only raise the age to 12 years old, then 456 out of the 499 children under 14 in prison last year will remain locked away.”