Patterns have been observed in academic grades of 1.6 million students, showing that girls and boys perform very similarly in STEM.

UNSW researchers have compared gender differences in variation of academic grades from over 1.6 million students aged six through to university from all over the world, across 268 different schools and classrooms.

“We combined data from hundreds of studies, and used a method developed by my supervisor to comprehensively test for greater male variability in academic performance,” lead author Rose O’Dea says.

A classroom with more variable grades indicates a bigger gap between high and low performing students, and greater male variability could result in boys outnumbering girls at the top and bottom of the class.

“Greater male variability is an old idea that people have used to claim that there will always be more male geniuses – and fools – in society,” Ms O’Dea said.

The team found that on average, girls’ grades were higher than boys’, and girls’ grades were less variable than boys’.

“We already knew that girls routinely outperform boys at school, and we also expected female grades to be less variable than those of males, so that wasn’t surprising. In fact, our study suggests that these two factors haven’t changed in 80 years,” Ms O’Dea said.

“However, what was most surprising was that both of these gender differences were far larger in non-STEM subjects, like English. In STEM subjects girls and boys received surprisingly similar grades, in both average and variability.”

In other words, the researchers demonstrated that academic STEM achievements of boys and girls are very similar – in fact, the analysis suggests that the top 10 per cent of a class contained equal numbers of girls and boys.

Ms O’Dea says that there are multiple reasons that these figures do not translate into equivalent participation in STEM jobs later in life.

“Even if men and women have equal abilities, STEM isn’t an equal playing field for women – and so women often go down paths with less male competition,” she said.

“For example, we found that the ability overlap between girls and boys is much greater in STEM, and smaller in non-STEM subjects, meaning that there are fewer boys competing with girls in non-STEM subjects.

“So say you're a girl in a class and you're a straight A student. In your math class, you’re surrounded by top-achieving boys, and then in English there's fewer boys that you're competing with, so it can look like non-STEM is an easier option or a safer path.”

Stereotypical societal beliefs about what fields girls are seen to be successful in also play a role.

“Girls are susceptible to conforming to stereotypes in the traditionally male-dominated fields of STEM. Girls who try to succeed in these fields are often hindered by backlash effects,” Ms O’Dea says.

“For example, the stereotype that girls aren’t good at maths actually makes it harder for girls to be good at maths, both because of the way we perceive ourselves and the way other people perceive us. We all have subconscious biases, and there’s a strange phenomenon called stereotype threat, where being reminded of the stereotype connected to your identity can make it harder to defy that stereotype.”