New research reveals patterns in STEM grades of girls vs boys

PhD student Rose O'Dea and co-author Associate Professor Shinichi Nakagawa from the University of New South Wales (UNSW) have published a study in the prestigious Nature Communications journal that explores gender differences in children's academic grades in STEM subjects.

This new study 'Gender differences in individual variation in academic grades fail to fit expected patterns for STEM' casts doubt on the view that there are fewer women in STEM-related jobs because they aren’t as capable in those subjects as men – a notion that has been supported by the concept that gender differences in variability lead to gender gaps in associated fields.

Over 1.6 million students aged six through to university-age from all over the world, across 268 different schools and classrooms, were compared in the Nature Communications study.

The gender differences in both the mean and variance of grades were smaller in STEM subjects than in non STEM subjects.

This suggests that greater variability is an insufficient explanation for male over-representation in STEM. “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.

“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”.

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.

The study demonstrates 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. 

So why is there an over-representation of males in STEM fields if females and males have equal abilities? O'Dea says there are multiple reasons that these figures don’t translate into equivalent participation in STEM jobs later in life.

"STEM isn’t an equal playing field for women – and so women often go down paths with less male competition.

"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,” 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.”

O’Dea says that there’s no simple fix for the under-representation of women in STEM.

“Science and academia have a lot of structural issues that will take time to fix. However, there’s a lot we can do to encourage girls to perform better at maths – for example, girls tend to do better when they're taught by a woman with a strong maths background, so they can see they can do maths, too.”

"This powerful, evidence-based research has revealed that girls and boys are equally good at STEM subjects. Differential participation in STEM training and STEM careers must therefore be explained by other factors." says Professor Emma Johnston, Dean of Science at UNSW.

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