I had reported Haldane as saying, in a pub, that he had decided that he was prepared to lay down his life for two brothers or ten cousins, or eight cousins, I can't remember. And this was in '56, '57, '58, that sort of date. And it's hard to see how Haldane could possibly have said that unless he understood the principle of inclusive fitness. I said this in a lecture, or reported it somewhere, and I think Bill felt very resentful that I was trying to take the credit from him and give it to Haldane. I really was just using Haldane's aphorism as a particularly clear way of explaining the idea, and it is a very clear way of explaining the idea. But I do think it's interesting why... I think for a time Bill just didn't believe the story. I think he understands now, that it's true, other people have heard Haldane say the same thing, but more importantly than that, he actually wrote it.

[Q] It's in the New Biology.

It's in New Biology. He said exactly the same thing at the same time in New Biology, so I think there's no question that the idea was there. But what is striking is that Haldane did nothing with the idea. He didn't see it as the clue to understanding the evolution of social behaviour. He didn't develop it mathematically. He states it as being true for a rare gene, which is rather easy to prove. What he didn't do was to struggle with the hard part to show that it's true even if the gene isn't rare, which is what Bill did in his papers and so on. But most important, he didn't do anything with the idea, and nor did I. And yet I understood it perfectly clearly when he said it to me, but neither of us saw it as important.