It depends on if we're measuring physical/genetic potential or end result of lives people live and their environment. I think both men and women have the genetic potential to be equally intelligent on average (some more than others).
However when we're talking end result, I think there are more truly intelligent adult men than adult women. This is because in our society women don't always have the same options, though this is rapidly changing and becoming less relevant every year. The other issue for women is that even with the same options I still see many girls adopting the ditsy silly girl mentality, especially when they're younger. I guess they feel that's how women are supposed to behave. If you play that role long enough and isolate yourself from life experience and a broad education and you'll wind up the character you play. That's why in the end we see what we see.
I was just thinking about this the other night. This girl that I'm casually seeing can be intelligent, but she's still immature (shes 23). When we're out alone or sleeping over she doesn't act dumb. However when she's with her girlfriends I hear shit that goes something like this:
Friend A: What the hell does domicile mean?
Friend B: I don't know it some stupid word...
My Lady Friend: Yea that's some bullshit!
Later I'm like LOL wtf, just because you're blond you don't have to play dumb. I know you know what domicile means. Shit you graduated college with a decent GPA. She's like "yea, I don't know why I said that..."
Ladies, it's not attractive, at least not to me. I'm sure if she keeps that up she'll wind up an idiot like her friends. Surround your self with smart people, don't be intimidated by those that may be smarter than you. Maybe you'll learn from them.