Is mathematical ability a bell curve?

I have no idea; sorry, saying so was bad epistemic hygiene. I thought I'd heard something like that but people often say bell curve when they mean any sort of bell-like distribution.

Also anecdotal, but it seems that when people come from an education system that privileges math (like Europe or Asia as opposed to the US) the proportion of women who pursue math is higher.

I'm left confused as to how to update on this information... I don't know how large such an effect is, nor what the original literature on gender difference says, which means that I don't really know what I'm talking about, and that's not a good place to be. I'll make sure to do more research before making such claims in the future.