I was just thinking about this today. To interview a potential co-founder I'd have a meal with the person and their SO. Then I'd observe the dynamic between them. Does the potential co-founder treat the SO poorly? Or is it reversed? Ideally they treat each other well. But there's more subtle hints to observe. Do they interrupt each other? If so what's the fallout?
The point is to assess the person's "people skills." I think "people skills" or in general "emotional maturity" is by far the most important factor in someone you need to work with on an intense level. Be that co-founder, SO etc.
The whole idea some people have of meeting a cofounder a few times (especially in an artificial environment like a hackathon) and then making an all-of-nothing decision is flawed, IMO. The best process is to spend a LOT of time with the person, and work with him on progressively larger projects. Yes, how they interact with people is an important factor, but I'd try to spend many months (or years) on the process, not a few meals.
Or how they treat the staff at a dinner. Many other routes vs making some people uncomfortable that you may "require" a dinner with a SO. If they don't have a SO, what, invite a friend to an interview?
Good point. I wouldn't formally require the SO. I'd just phrase the invite to make it clear that my SO and I would like to have dinner. If they have an SO but don't bring them that's another potential signal (could be good or bad).
The point is to assess the person's "people skills." I think "people skills" or in general "emotional maturity" is by far the most important factor in someone you need to work with on an intense level. Be that co-founder, SO etc.