Do we over-rate the importance of individual talents to organizational performance? I ask because of this finding by Sander Hoogendoorn:

Team performance exhibits an inverse u-shaped relationship with ability dispersion.

This comes from a study of MBA students' collaborations on business projects. But it is consistent with a finding from baseball, that teams with middling levels of ability dispersion do better than those with low or high dispersion.

It's easy to hypothesise why this might be so. Where's there's middling levels of ability dispersion, less able team members can learn from their superiors. But if there's too much dispersion, they might instead rely too much upon their superstar and shirk responsibility themselves.

Although the only formal study of this hypothesis for football is ambiguous, it is consistent with something Bill Shankly said: "A football team is like a piano. You need eight men to carry it and three who can play the damn thing" - that is, a middling ability distribution. Spurs' sad failure to qualify for the Champions League also corroborates it. They - more than Arsenal or Chelsea - probably have a greater dispersal of ability; the performance gap between Bale and (say) Adebayor is probably larger than than between any two regular Arsenal players*.

All this evidence suggests that relying upon a single superstar is dangerous. There's other evidence for this. Boris Groysberg has shown that the performance of apparently superstar equity analysts declines when they move firm. And many TV shows continue to thrive after the departure of their apparent stars; one of the more significant and forgotten facts of the 1970s was that the Generation Game reached its peak of popularity after Bruce Forsyth left and was replaced by Larry Grayson.

But its not just in important matters such as sport and TV where an excessively lop-sided dispersion of ability can have adverse effects. The same might also be true in politics. The two dominant politicians of our age have been Thatcher and Blair. But under and after their leadership, their parties decayed in both membership, finances and, perhaps, intellectual vigour.

Sure, superstars can sometimes transform a team or organization. But other times, they can serve like Potemkin villages - a healthy facade behind which lies nothing of substance.

* Remember, we're controlling for average ability here.