I disagree. I was in a fraternity in college and while it was a GREAT time to expand my horizons (I didn't party much in high school) I received almost no social support for my entrepreneurial/hacker tendencies. Most of it was mocked. So I learned valuable social skills and how to persevere without social support but imagine how effective I'd be if I had social support.
Yeah, but what kind of activities were you involved with in the fraternity? Partying and athletics are active certainly, and enjoyable, but not creative.
You want people who are motivated primarily to make things happen. As with what evandavid said, people with artistic interests or who are engaged with a professional career are good, but anyone with a hobby that's more creative than "going out drinking" and more active than "playing videogames" fits the bill--even that guy who spends thousands of dollars hand-crafting historical costumes and goes to a renaissance faire every other weekend is actually out doing something.
The important part is that, at least in my experience, people who are motivated, creative, and actively engaged with what they're doing will (even if only implicitly) support and encourage that mindset in each other, even with widely divergent interests.
