A powerful argument for how to succeed in any field: develop broad interests and skills while everyone around you is rushing to specialize.

Plenty of experts argue that anyone who wants to develop a skill, play an instrument, or lead their field should start early, focus intensely, and rack up as many hours of deliberate practice as possible. If you dabble or delay, you'll never catch up to the people who got a head start. But a closer look at research on the world's top performers,...