He shared a Nobel Prize with John Bardeen and Walter Brattain for the invention of the transistor and later went on to refine transistor technology, spawning the modern age of semiconductors and of Silicon Valley.
It may very well have gone back to the telephone call that Bardeen and Brattain had made when they told him that they had come up with a - they had the transistor effect in the laboratory.
He was afraid that he hired people who were at least as smart as he was and that they were going to do better things than he could do, as Bardeen and Brattain had done at Bell Labs.