I didn't mention statistics! Boys and girls definitely are different, but that doesn't mean you should dismiss cultural effects, it just means you shouldn't ignore the fact that boys and girls are different. Can you do that? The list of countries where the gender split in STEM is most even are not in the free world. When people have more choices they are more likely to be influenced along gender lines. If that's not the sort of culture you want, then go to Iran (it's top of the list).
Even if girls and boys are equally good at maths you'd expect more men to be mathematicians if women are better communicators and more able to use their mathematical skills in better paid professions. And that's what happens.
Teaching and psychology are well paid professions where men are underrepresented. Medicine and Dentistry students are 58% female, Law students are 62% female, student vets are 80% female (The Guardian, degrees awarded in 2012). Nobody cares because it favours women. Refuse collectors are poorly paid and men are overrepresented there. Nobody cares because it favours women.
"we need to keep the pressure on to truly change this."
And the grants and encouragement which girls get and boys don't? It would be good to change that and treat people equally.