Basically, most women choose to not pursue engineering if they don't have to (unfortunately, I'm glad we have some women at the office).
For example this chart for Asian countries does have Iran on one side and Japan on the other, but it also have Korea way higher than Japan and Cambodia way lower.
https://en.wikipedia.org/wiki/Women_in_STEM_fields#/media/Fi...
In europe Norway has the fewest women in stem and Croatia the highest, but there are a lot of cases where the correlation isn't there. Hungary is very low and Luxembourg is very high. Ireland and Italy are high but Slovenia is low.
https://ec.europa.eu/research/swafs/pdf/pub_gender_equality/...
Correlation definitely exists but there are a lot of other factors at play too.
Heres some more studies I found interesting. I'm sorry if this list looks biased, its just what I could find. If anyone knows of (statistically sound) contradicting studies, please share!
"Practically all psychological differences between men and women were LARGER in cultures with more gender egalitarianism." http://onlinelibrary.wiley.com/doi/10.1002/ijop.12265/full
"Women tend to shy away from career opportunities that explicitly make "brilliance" a condition." http://www.sciencedirect.com/science/article/pii/S0022103117...
"Women prefer less risk and less competition, appear to prioritize equality over efficiency and report a greater willingness to share wealth." https://ideas.repec.org/p/hhs/gunwpe/0713.html
"Personality had greater impact on variance in income than sex, narcissistic men earning more, neurotic women less." http://www.sciencedirect.com/science/article/pii/S0191886917...
"Women saw typical engineers & computer scientists as more extreme & stereotype-consistent, sabotaging themselves" https://link.springer.com/article/10.1007/s11199-017-0763-x
"The wage gap between men and women vanishes after controlling for so-called "reservation wages"." http://www.sciencedirect.com/science/article/pii/S0167268117...
"Women underestimate, while men overestimate their labor market prospects, leading to greater female job satisfaction" http://www.sciencedirect.com/science/article/pii/S0167268117...
"Women with managerial careers are significantly less satisfied with their life than their male counterparts." https://link.springer.com/article/10.1007/s10902-016-9832-z