Meanwhile, it turns out that boys aren't necessarily better at math, when you start to compare test results in different countries:
In countries where women occupy an equal position to men in society, such as Sweden, there was virtually no gender gap in maths ability. However, in countries with lower levels of gender equality, such as Turkey, the boys performed better in maths tests than the girls.
"The gender gap in mathematics doesn't seem to be a feature of every society," says Sapienza.
What's more, the girls produced better reading scores than the boys in all the countries looked at, but did even better in countries with higher levels of gender equality.