What is Dunbar's number? Well, in short, it's the idea that human beings can only hold about 150 meaningful relationships in their heads. Read much more about it here. The number came about while British anthropologist, Robin Dunbar, was doing research about the business model of Bill Gore, one of the creators of Gore-Tex.While Gore-Tex was growing in the 1980s, Gore would visit his factory and realize he didn't know everyone working there. He came to the conclusion that once a company had more than 150 people, things no longer ran smoothly. So he made a decision to cap the factory at 150 employees, and when the company needed to expand, he would build another factory.Read more about Gore's business model and listen to the All Thing Considered episode about Dunbar's number here.MP3: George Harrison - Devil's Radio