But 10 x 1 does not equal 1 x 10. Imagine you have ten roles to fill, and you ask ten colleagues to each hire one person. Obviously each person will try to recruit the best person they can find — that’s the same as asking on person to choose the ten best hires he can find, right? Wrong. Anyone choosing a group of ten people will instinctively deploy a much wider variance than someone hiring one person. The reason for this is that with one person we look for conformity, but with ten people we look for complementarity.
If you were only allowed to eat one food, you might choose the potato. Barring a few vitamins and trace minerals, it contains all the essential amino acids you need to build proteins, repair cells and fight diseases – eating just five a day would support you for weeks. However, if you were told you could only eat ten food for the rest of your life, you would not choose ten different types of potato. In fact, you may not choose potatoes at all — you would probably choose something more varied.
Excerpt from: Alchemy: The Surprising Power of Ideas That Don’t Make Sense by Rory Sutherland