In “Leading Teams: Setting the Stage for Great Performances”, J. Richard Hackman lays out five conditions necessary for successful teamwork: The team must be a real team, rather than a team in name only; it has compelling direction for its work; it has an enabling structure that facilitates teamwork; it operates within a supportive organizational context; and it has expert teamwork coaching.
Says Hackman about team composition in an interview:
Composing teams that are too large and too homogeneous in membership. My rule of thumb is that no work team should have membership in the double digits (and my preferred size is six), since our research has shown that the number of performance problems a team encounters increases exponentially as team size increases. Homogeneity of membership is a frequent problem because each of us works most easily and comfortably with people like ourselves. I would no doubt get along very well in a group whose other members also are middle-aged white male pipe-smoking professors. We might very much enjoy our time together. But our creativity would be higher if our group had a diverse mix of memberspeople who have real substantive differences in their views about how the work should be structured and executed. It is task-related conflict, not interpersonal harmony, that spurs team excellence.