I know I'm not a communication expert so I have to take my own observations with a grain of salt, but I would say I only have trouble conversing with maybe half the population because of my inclination to not interrupt. But I've noticed no gender or geographic trend to this. Some groups of men or women I'm able to converse with smoothly, as they seem to deliberately pause to let other's speak. In other groups, I'm hopeless. Perhaps it's an introvert/extrovert divide (I'm skeptical of that dichotomy, but that's another can of worms.) I can talk comfortably one-on-one with my mother or any of her sisters, but put two or more of them in the same room and I'll not get a word in edgewise. For that matter, I also feel fine monologuing in front of an audience and always have, so I think it's not simply a matter of shyness.