When Teenagers Stop Studying Maths, a Key Brain Chemical Drops

Oxford scanned the brains of 87 adolescents. Half had continued studying maths after the age of 16. Half had stopped. The ones who stopped had measurably less of a particular neurotransmitter in a region tied to reasoning, and the researchers were then able to show this wasn't the case before they'd stopped.

This is a study about 16-year-olds. The reason it matters for parents of six-year-olds is different, but it matters more.

What they actually measured

The study was led by Roi Cohen Kadosh's group at the University of Oxford's Wellcome Centre for Integrative Neuroimaging, and was published in PNAS in 2021 (Zacharopoulos, Sella & Cohen Kadosh, DOI: 10.1073/pnas.2013155118). They used magnetic resonance spectroscopy, a type of brain scan that can measure the concentration of specific neurotransmitters, on two regions of the brain known to be involved in numerical thinking: the intraparietal sulcus and the middle frontal gyrus.

They were looking at GABA. GABA is the brain's main inhibitory neurotransmitter, the chemical that calms and coordinates neural activity. In adolescence, GABA is still maturing. Frontal GABA levels don't reach adult levels until late in the teenage years, and lower GABA during those years has been linked to poorer cognitive functioning.

The question the researchers asked was narrow. Could they tell, just from brain chemistry, which teenagers were studying maths and which weren't?

What they found

Yes. They could.

Teenagers who had stopped maths had significantly lower GABA concentrations in the middle frontal gyrus. The effect was specific to that region and specific to GABA. Other chemicals in other regions weren't predictive. It also wasn't explained by stopping other subjects like biology or chemistry. The association was with the absence of maths, not with any broader lack of study.

More striking: GABA levels at 16 predicted the changes in each teenager's mathematical reasoning scores nineteen months later. The chemistry wasn't just a snapshot of a past decision. It forecast how their maths would develop from that point on.

The finding that wasn't in the brief

The obvious worry with a study like this is that it's backwards. Maybe teenagers with lower GABA were the ones who struggled with maths in the first place, and so they chose to drop it. The chemistry would then be the cause of the decision, not the result of it.

The researchers anticipated this. In a second experiment, they examined younger adolescents who hadn't yet made the decision, and found no GABA difference between those who would later continue and those who would later stop. The chemistry diverged after the education did, not before.

That is what makes this a study about the effect of education on the brain, rather than the other way round.

What this doesn't mean

This is not a study about whether your seven-year-old should do more maths worksheets.

The research is specifically about sustained formal maths education through adolescence, in a country (the UK) where students can choose to stop at 16. It does not tell us anything about whether a given week of extra homework will change a child's brain. It does not measure the effect of any particular teaching method.

What it measures is what happens when the thinking that maths demands (abstract reasoning, working memory, sustained attention to problems with no obvious answer) simply stops being trained. And it shows that the training itself shapes the biology that makes further training possible.

Why this lands on a parent of a six-year-old

Because the premise of the study only works if maths is shaping the brain while it's being studied. The researchers aren't claiming the effect begins at sixteen. They're claiming that what disappears at sixteen, when it disappears, takes something biological with it.

The years where most of that shaping happens are the years before.

Five to ten is when children build number sense, spatial reasoning, and the sense that problems with no obvious answer are worth attempting. Those three foundations feed directly into the kind of thinking that, a decade later, keeps the GABA levels up. If a child reaches sixteen with a strong foundation and stops maths, the study suggests something measurable is lost. If they reach sixteen without one, the loss started earlier.

This is the same argument made from a different angle in the research on spatial skills, where children who can hold and rotate images in their minds find maths less mysterious when it arrives. It's the same pattern found in the eye-tracking work on six-to-eight-year-olds learning robotics, whose visuospatial working memory improved measurably over a few months. The brain responds to what it's given.

The honest caveats

The study is a strong one, but worth reading carefully. The sample was 87 teenagers in one country's education system. The finding is about correlation at a group level, not a prediction about any individual child. GABA is one neurotransmitter among many, and the middle frontal gyrus is one of many regions involved in numerical thinking.

The researchers themselves are cautious about the implication. Cohen Kadosh has said that not every adolescent enjoys maths, and that alternatives engaging the same brain area (logic, reasoning, structured problem-solving) should be investigated. The point isn't that every child should do more maths. The point is that the kind of thinking maths demands has a biological footprint, and that footprint depends on practice.

What a parent of a young child can take from this

Not more worksheets.

What the study quietly argues for is engagement: the kind that keeps a child reaching for structured reasoning in the years when that reaching is wiring their brain. Puzzles, building, games with rules, conversations at dinner about how big a million really is compared with a billion. Robotics, if it interests them. Twenty minutes at the kitchen table working out why a flat sheet of paper won't hold a penny but a folded one will. A parent who can sit with a child through a hard problem instead of solving it for them.

None of that feels like maths. That is rather the point.

The study doesn't claim these activities raise test scores. It suggests something subtler: the foundation being built right now determines what the brain has to work with later. A child who reaches sixteen with the wiring already in place will get more from whatever maths they continue. A child who doesn't will get less, and, eventually, stop.

The GABA drops because the thinking stops. Keep the thinking going, and the chemistry takes care of itself.