Finding: All of the Silicon Valley's top IT entrepreneurs were born between these three years.
Reasoning: January 1975 was when Popular Electronics ran a cover story on an extraordinary do-it-yourself contraption that could be assembled at home. Gladwell notes that this was the dawn of the personal computer age, and those who could innovate off it had to fall in the right age range - they couldn't be too young and not ready, but they couldn't be too far out of college that they had already settled in a house with kids. That left those generally born between 1953 and 1956, such as Microsoft co-founders Bill Gates and Paul Allen, Apple founder Steve Jobs, and Google CEO Eric Schmidt.