I was very lucky. I was just finishing my PhD at Cambridge in 1981. This opportunity came up because whaling was drawing to an end. There was the prospect of a moratorium, and one of the arguments that was brought up, especially by Japanese whalers, was that, if we didn't have whaling, we would know nothing of whales. All the science depends on having dead animals, they argued, so that's one of the benefits of the whaling industry.

But one thing that seems pretty clear when we look at human religion is that it's highly tied in with human culture. So if, as seems to be the case, culture's governing a lot of what whales do, it's perhaps not an unreasonable hypothesis to think that it's got elements of...what I guess you'd call the supernatural.

A bunch of individuals do the same thing because they learned from watching each other or somebody else. That's what we would call culture.

When I'm out in the ocean and I watch a seabird, I think, "Oh, I probably I know what that seabird is doing" - and I don't study seabirds. And the same for the turtles and on and on. But with the whales, a lot of the time, I have no idea what they're doing, and they're the ones I study.

What I mean by it, and roughly what most biologists who talk about culture mean by it, is either behavior itself, or information that leads to behavior. Information that is picked up through social learning - so, from being with, watching, being taught by others. It's a way that individuals behave or get information about how they will behave that comes directly from the behavior of others.

The actual communicative value of what we say is usually quite small. I've lived for times in small, isolated fishing villages, where everyone knows everyone each other and everyone knows what's going on and everyone's watched the same TV programs and, really, there's not a whole lot of new information to convey. But there's still a lot of talking. What's said doesn't seem to matter; that you say it, and who you say it to, and how you say it is what matters.

Culture is not usually one of the criterion for personhood, but it has been argued that culture is sort of a medium for a lot of these criteria, such as empathy, and so on.