Research finds the threat comes in two flavours. Women can fear their poor performance will be used to bolster the "women are weak at maths" gender stereotype (known as "group-reputation threat"). Or they can fear that their poor performance will be taken as proof that they conform to the stereotype ("self-reputation threat"). Both can undermine women's ability to fulfil their true potential.Apart from the odd jargon, the article could point to a way of restoring confidence.
Overall, men outperformed women on the maths task. But women who took the test under someone else's name, be it male or female, performed better than women who performed under their own name, and they did just as well as the men. The effect was stronger for women who cared more about maths.The research was done on undergraduates - I wonder if it is replicated in younger people.