Well, if it's not genetic, and it's not cultural, then I'd be interested in your alternative hypotheses. Because we live in an "advanced" Western civilization which only, after millennia of feminine marginalization, have reluctantly allowed equality of opportunity for women for only the last 3-4 decades, and yet we can still see a math gap in only 35/65 participating nations... so it's most definitely NOT genetics.
You're acting as though strong evidence for a cultural component to the gap also constitutes evidence against a genetic component. It doesn't. There's a range of measures of the gap that varies from county to country. You don't know how the gap would measure in a country with a culture perfectly neutral (or perfectly balanced) in all aspects that affect the gap. When you say "it's most definitely NOT genetics" you are taking a leap of faith that is not supported by the data.
