School leaders should approach class placement decisions carefully. A CQUniversity educational neuroscientist is warning that how students are grouped can shape how they see their own potential.
Professor Ken Purnell, head of educational neuroscience at CQUniversity in Queensland, said class lists can help schools organise learning. However, they should not be treated as a measure of a student's ability to grow. The issue has returned to focus amid renewed debate about ability grouping in Australian schools.
A 2026 study led by Professor Becky Taylor and Professor Jeremy Hodgen at the UCL Institute of Education found that high-achieving maths students in England made approximately two months' more progress when taught in streamed classes.
Ability grouping, often referred to as streaming, involves placing students into classes based on perceived academic achievement. Higher-performing students may be grouped together, while those needing more support are taught separately.
Why streaming is back on the agenda
For school leaders, the question is not simply whether streaming should be used. The larger issue is how class placement affects teaching, expectations and student confidence.
Australia has a long history of ability grouping, particularly in secondary mathematics. Some schools have moved away from the practice in recent years in a bid to be more inclusive, but streaming remains the norm nationally.
The renewed debate follows the UCL findings, which are among the most comprehensive to emerge from England in years. The study was commissioned by the Education Endowment Foundation to provide up-to-date evidence from English schools.
What the research actually says about streaming
"Whenever we talk about streaming, there's a temptation to frame it as either good or bad," Professor Purnell said. "The evidence is much more nuanced than that."
The UCL study examined maths results among Year 7 and Year 8 students aged 11 to 13, across 97 schools in England. Twenty-eight schools used mixed-ability grouping and 69 used streaming.
Students who were not streamed made only one month less overall progress after two years. Students from disadvantaged backgrounds and those with lower prior achievement made similar progress regardless of how they were grouped.
Professor Purnell cautioned against treating these findings as a broad endorsement of streaming across all schools or cohorts. Class structure, he said, is only one part of the equation. What matters more is the instruction students receive after they are placed.
That places responsibility on schools to ensure every class receives appropriate challenge, support and feedback — whether students are taught in streamed or mixed-ability settings.
When class placement becomes a label
The risk is that class placement can become more than an administrative decision. For some students, it can become a label.
"One of the risks of streaming is that it can unintentionally become a label," Professor Purnell said.
A student placed in a lower group may begin to see that placement as evidence they are not capable. Over time, that belief can affect confidence, motivation and achievement.
Expectations also play a role. Students are shaped by the signals they receive from teachers, parents and themselves about what they can achieve. "Research consistently shows that students are influenced by the expectations around them," Professor Purnell said.
"They often rise — or fall — to what they perceive those expectations to be."
Brain science and the question of fixed ability
Professor Purnell said neuroscience offers an important reminder for schools reviewing grouping practices. Student ability should not be treated as fixed during childhood or adolescence.
Neuroplasticity — the brain's capacity to form new connections through experience and learning — means the potential for development does not close at a particular age or year level.
Challenge, practice and feedback all contribute to how students develop.
For schools, this means avoiding messages — however unintentional — that suggest a student's future has already been decided by a class placement.
The Australian Institute for Teaching and School Leadership's (AITSL) Australian Professional Standards for Teachers requires teachers to differentiate instruction across the full range of student abilities. Standard 1.5 specifically addresses meeting students' diverse learning needs — regardless of how classes are structured.
What the evidence says matters most
Professor Purnell compared academic development with sport, where some athletes improve through training with stronger peers. Some students may experience similar benefits in high-achieving classroom environments. But the principle applies across all groups.
Schools that focus only on class structure, he said, risk missing the more important question.
"The real question is whether every student is being challenged, supported and encouraged to believe they can improve," he said.
"That is what the evidence tells us matters most."