A new study has shown girls perform just as well as boys in STEM subjects, disproving the stubborn stereotype that the underrepresentation of women in science, technology, engineering and maths disciplines is due to a lack of aptitude.

The UNSW study assessed 1.6 million grades, both STEM and non-STEM, of school-aged children across Year 1 to university from 268 different schools or classrooms, with the majority based in North America.  

Published in the prestigious journal Nature Communications, the analysis showed girls and boys perform very similarly in STEM – including at the top of the class.

“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,” O’Dea says.

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,” O’Dea says.

“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% of a class contained equal numbers of girls and boys.

Professor Emma Johnston, the Dean of Science at UNSW, and the president of Science and Technology Australia, said the results raised questions about why so few women were working in STEM fields compared to men.

“We look across the spectrum of people working in science and technology and we see a strong gender bias there,” she told ABC News.

“We’d like to be able to explain them, because if we can explain and understand them, then maybe we can rectify the situation and reduce the bias.”

Young IPWEA Australasia Chair Nicola Daaboul said she hoped studies like this would help identify the real reasons women aren’t studying STEM subjects or choosing a career in STEM.

“And, more importantly, help us to identify what we can, and should be doing to support and encourage more women in STEM fields,” she said.

“It doesn't surprise me at all to hear that women perform just as well, if not better than men in STEM subjects.

“Some people might ask ‘Why is it so important to encourage women in STEM?’. In my opinion, it encourages diversity of thought, which is important for our industry to innovate, thrive and grow.”