A popular narrative about innovation assumes breakthrough ideas emerge primarily from group brainstorming and collaborative energy — open offices, constant meetings, freewheeling team sessions. Research on both individual case histories and controlled studies of creative professionals suggests something closer to the opposite: many of the most significant creative and technical achievements were produced by people working alone, in extended, uninterrupted solitude, often well before any collaborative or public phase began.
This doesn't mean collaboration has no value — it means the popular emphasis on collaboration as the primary engine of creativity misdescribes how a great deal of actual creative and technical work gets done, and can crowd out exactly the solitary conditions many people (not only introverts) need to do their best thinking.
Steve Wozniak designed the prototype for the Apple I almost entirely alone, working nights in solitude at Hewlett-Packard for months before ever showing the design to anyone, including Steve Jobs — a sharp contrast to the popular image of Silicon Valley innovation as a collaborative garage-startup story. Cain pairs this with mid-century research from UC Berkeley's Institute of Personality Assessment and Research, which studied unusually creative architects, writers, and scientists and found them to be reserved and independent-minded, often more comfortable working alone than in groups, despite being capable of sociability when it was actually needed.