It's long been known that Māori students are more likely to get kicked out of school. The phenomenon has been blamed on factors outside the classroom, from higher rates of poverty to parents' education levels.
But new research has found after stripping away those factors, Māori kids are still nearly 50 per cent more likely to be stood down, suspended or excluded from school than Pākehā.
That finding underlines what experts have said for decades - that systemic and personal racial bias is hurting Māori learners, leaving them with worse educational outcomes that can have ripple effects for the rest of their lives.
The as-yet-unpublished research looked at more than 43,000 students who started school in 2008, finishing compulsory education in 2018. Researchers looked at factors known to affect educational outcomes, such as parents' income, history of abuse, whether they received learning support, and home ownership, using anonymised data from Statistics NZ's integrated data infrastructure.
They found similar background factors were good predictors of exclusion rates for both Māori and Pākehā students. But when these variables were removed, Māori students were still nearly 50 per cent more likely to get stood down, suspended or excluded over the course of their schooling than Pākehā.
Pacific students were also more likely to be excluded, but once background factors like poverty were removed they were excluded at similar rates to Pākehā - though the picture was complicated by whether they received English for Speakers of Other Languages (ESOL) support.
The paper is based on a Masters thesis by Cassia-Rose Hingston at the University of Canterbury. Her supervisor, senior lecturer Dr Steve Agnew, said family background and socioeconomic factors were often blamed for Māori and Pacific students' higher exclusion rates, but the research showed that wasn't the whole story.
He said one possibility was known as the Pygmalion effect - the idea that teachers' expectations of students' achievement can become a self-fulfilling prophecy. That unconscious bias may have a similar impact on exclusion rates.
Dr Hana O'Regan, tumu whakarae (chief executive) of CORE Education, said there was plenty of evidence showing bias and negative stereotypes contributed to Māori kids' poorer educational outcomes. Exclusion was part of a bigger picture that included other practices like unfairly streaming Māori kids into the lowest classes.
"We've got negative expectation, we've got policy that actually feeds and fosters it, worldviews that have gone unchecked ... to the point that we just believe it," she said. The end result was that kids gave up, and began behaving badly because their teacher expected it, she said.
"My son says to me, 'Mum, everyone can be talking in the class - it'll be the Māori ones who get pulled up. We're doing no different from anyone else - we're the ones who get detention'."
There were parallels in the justice system, where Māori were far more likely to be charged or receive a custodial sentence compared to Pākehā who committed the same offence.
"In an education context ... you're more likely to be expelled for the same offence if you're Māori, or even go through the [disciplinary] process," she said.
And she said it was still common in the education system to blame socioecomic and whānau factors for poor outcomes.
"There's no acceptance that the people in power, those that are making the decisions around that education context, have any responsibility for what's happening."
The research finding that the same issues didn't apply to Pacific students also didn't surprise her.
"They will stay in school longer but they don't get equitable results ... which is another indictment on the system."
O'Regan - who spoke at a PPTA summit this week on how inequity is baked into our education system - said New Zealanders had become good at justifying and ignoring inequity.
Teachers and school boards were part of a society that was a product of its time, she said.
Instead of attacking teachers for having negative expectations of Māori, "we have to unpack the fact that this is the journey that we've been on as a country".
O'Regan acknowledged there were "significant shifts" in attitudes and practices happening within the education sector, from teaching Aotearoa NZ's Histories in schools to seeing the value of te reo Māori. But she wished change had come earlier.
"I haven't been able to shield my own children from this - I want to be confident that my mokopuna [grandchildren] won't be experiencing the same challenges."