I've gotten this same comment on a few occasions. If I know the woman already, they'll say it's due to an intelligence difference.
Something else I've been told by these same women is that I have a piercing gaze. If I'm showing a neutral expression or being non-sexual, women won't look at me twice if I look at them, it's like I'm invisible. If I put some sex or aknowing smile in the gaze, there's an automatic change in them and I'll get held looks and smiles most of the time. It's a pretty powerful tool.
The other interesting tidbit, from my experience at least, is that the women who will actually tell you something like that aren't necessarily the smartest girls in the world, but they don't fall for the feminist world view.