As a youth, I participated in the Rancocas Valley Commodore Users Group in southern New Jersey. At that point in time, Commodore had a sizeable share of the home computing market, and meetings reflected this, with a broad ranges of ages represented, and a gender imbalance that wasn't too bad for "back then."More recently, I made it to two or three meetings - over the last two years - of the Big Island Linux Users Group here in Hilo. The demographics of this group were distinctly different. I don't recall seeing anyone I'd consider a kid - it was pretty much college age and up - and the majority of participants were male.
This evening, I attended my first meeting of Hawaii Mac Nuts, a Macintosh Users Group which also meets in Hilo. (I use both Linux and Macintosh, and know that I'm hardly alone in doing so.) I still didn't see any kids, but one lady who I believe to be a teacher brought in some peripherals for "show and tell" that she'd borrowed from kids. The gender balance was basically 50-50, though.
Of course, I've yet to attend a Windows Users Group, so I can't say for sure whether Macintosh users are more or less gender-balanced than "the majority," so to speak. I'd expect a pretty even gender split among Windows users, but that might not hold true when it comes to attending users group meetings.
Anyway, I'd definitely recommend Hawaii Mac Nuts to anyone in the Hilo area who uses a Macintosh. There are some very knowledgeable people there, and overall the meeting was enjoyable and informative.