Here's How People Successfully Work With Friends, Family and Even Their Spouse The key to a happy life: Clearly defined roles and responsibilities.

When I say that my wife and I wrote a novel together, people's first reaction is almost universal: "You're still married?" The idea seems terrifying -- but we loved it. The project took us three years, and though we had disagreements along the way, we kept each other motivated and focused. (And it's coming out this October! It's called Mr. Nice Guy.) If it worked for us, I suspect it could work for many entrepreneurs. Ambition can be a lonely road. Isn't it nice to have support?

Related: The Science Behind Working With Your Spouse

This got me wondering: How many people work with friends and family -- and how's it going for them? To find out, Entrepreneur partnered with SurveyMonkey Audience to survey 1,007 people across America. The first big revelation: It's actually quite common. Of our respondents, 78 percent said they'd worked with a close friend, family member or significant other.