Last week, I found myself sitting next to a woman at dinner who chairs companies. We were talking about boardroom diversity, and she suddenly declared: “I always make sure that there is one shit on each of my boards.”

I wanted to kiss her. It was not just the word, so sharp in contrast to the soft drivel that nearly everyone lets rip whenever they discuss diversity. It was also the bracing sentiment that delighted me, even if I had a nagging doubt that she might be wrong. Surely, I protested, the ideal number of egos on a board was zero?

She looked at me with exaggerated patience, as if I were an amiable, if dim, child. I was making the elementary mistake, she said, of confusing egos and shits. The ego has no place on any board, as he is only interested in himself. A cumbersome ego is no help at all when you are trying to examine the corporate risk register.