Students did better at maths, science in single-sex schools

Year 9 students at single-sex secondary schools did better at maths and science than peers at co-ed schools in a New Zealand study just published.

The biggest outperformance was by the girls at two low-decile single-sex schools versus their peers at 26 low-decile co-ed schools, according to the paper in New Zealand Journal of Educational Studies.

“This really surprised us,” says Dr Tanya Evans of the Mathematics Education Unit in the Department of Mathematics at Waipapa Taumata Rau, University of Auckland. “We expected boys to do better, in line with international studies, but the results for girls were unexpected.”

Data for more than 5,900 first year secondary school students was analysed from the Trends in International Mathematics and Science Study (TIMSS) 2019.

Because there were only two girls-only schools in the low decile band (deciles one to three), the results could be idiosyncratic and unable to support generalisations.

For Evans and fellow researcher Alice Smith, the main conclusion is that more research is needed.

“There is something very special happening at those two girls-only schools that enables maths and science achievement despite the odds – those girls also significantly outperformed boys in the low-decile boys’ schools,” says Evans. “This is remarkable.”

The researchers weren’t surprised that boys at single-sex schools outperformed those at co-ed schools across all deciles, saying the effect is “well documented” in international research.
 

However, the picture was more complicated for the girls.

While girls at lower socioeconomic single-sex schools outperformed their peers by the most, the effect was smaller at the mid-socioeconomic level (deciles 4 to 7) and “trivial” in statistical terms at the highest level (deciles 8 to 10.)

The scientists speculate that girls-only schools may be better at mitigating lingering negative stereotypes about girls’ abilities, but highlight that it’s too soon to say that single-sex environments are better for learning maths and science.

For one thing, there could be selection bias if academically strong learners prefer to enrol in single-sex schools. Also, data came from the end of the first year of secondary study without disclosing what happened over the subsequent years.

In New Zealand, about 14 percent of girls and 14 percent of boys attend boys-only or girls-only secondary schools.

Out of 2544 schools, including both secondary and primary, 64 are girls-only and 52 are boys-only. Unlike in the US and Australia, where single-sex schools are mainly private and/or Catholic, in New Zealand the majority are state schools.

The Mathematics Education Unit in the University’s Department of Mathematics looks into the teaching and learning of maths and statistics at school and university levels.

The TIMSS data is supplied on the basis that individual schools aren’t identified.