If there’s one thing we all have in common, it’s doing more with less—and that has turned everybody into a multitasker.

But doing too many things at once can leave us doing nothing particularly well, as researchers have proven and millions of ordinary people have discovered on their own. Robert Sutton, management professor at Stanford University and co-author of Scaling Up Excellence: Getting to More Without Settling for Less, calls this “the problem of more.”

“As job responsibilities grow, as organizations grow, all this stuff comes down on us,” Sutton--who also wrote the bestsellers Good Boss, Bad Boss and The No Asshole Rule--tells me in the video above. “The more cognitive overload we have, the dumber we get and the worse we do everything.”

In Scaling Up Excellence, Sutton and his co-author Huggy Rao, also a Stanford professor, describe how leaders can tap the qualities found in the most effective parts of their organization and spread them to every other division. It starts with leaders who know their limits.

“Part of your job for scaling excellence,” Sutton says, “is to take the load off of you. Teach others to do it the right way. You get ahead, and they get ahead.”

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Many bosses tend to be micromanagers who want to control everything they’re responsible for. But in addition to driving employees crazy, that approach doesn’t usually produce the best results. More effective, Sutton says, is knowing what your “power zones” are—what you’re best at—and letting others handle the rest.

Former Apple (AAPL) CEO Steve Jobs was renowned for running his company this way. He was maniacally focused on products, while delegating financial and supply-chain management to others. But Jobs learned to delegate the hard way, after an earlier and more turbulent period as CEO of NeXT, and then Pixar, in which he tried to control too much and produced poor-to-mediocre results. More than two years after Jobs’s death, Apple still emphasizes the virtues of a tailored workload—senior executives tend to become more specialized as they climb the ladder, with narrower, not wider, realms of responsibility.

(Check out the video to find out which other CEOs Sutton thinks delegate well, and poorly.)

You don’t have to be the CEO, or even the boss, to manage cognitive overload better and amp up your performance. One tip Sutton offers for multitasking better: Know what you’re good at, and prioritize that above other duties. That way, you’re spending your time doing something likely to produce the best results, instead of something others might do better.