1. this gender gap begins very early (kindergarden), before the majority of "women in STEM" programs begin
2. are international (i'm fairly certain they don't have women in STEM programs in China, for example)
3. it doesn't explain why the differences are inversely related to income level (do you think there are more "women in STEM" programs at lower income levels?)
4. this difference is very old (>50 years of this effect)