New research points that the bell curve isn’t really a natural distribution, but what happens when you put humans under constraints:

Human performance, by this account, does not often fit the bell curve or what scientists call a normal distribution. Rather, it is more likely to fit what scientists call a power distribution.

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Aguinis said the bell curve may describe human performance in the presence of some external constraint — such as an assembly line that moved at a certain speed.

“If you had a superstar performer working at your factory, well, that person could not do [a] better job than the assembly line would allow,” Aguinis said. “If you unconstrain the situation and allow people to perform as best as they can, you will see the emergence of a small minority of superstars who contribute a disproportionate amount of the output.”