What makes teams smart?
Joyce Park stashed this in Teamwork
I suppose having a strong "social" component to your interviews. Take them drinking or hiking or to sports events. Or board game/ video game night. Eventually, the interview "wall" should break down and you will get a chance to see how well they mesh with your team...
Alternatively, Hire people already in your social circle.
Sounds expensive and/or time-consuming! What about having group interviews at which the whole group is asked to solve some problem by the end?