What I mean is, if you look at the behavior of an animal and ask, "Well, why did it do that?" and then consider the alternatives, those alternatives probably wouldn't be as successful at getting its genes around.

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.

We believe we're seeing, in other animals, a process, or an attribute, that isn't fundamentally different from what we see in humans, so it seems to us to be spurious to call them different things. Now there are aspects of human culture that we don't find in animals, and that's really interesting, but there are also probably aspects of animal cultures that we don't find in humans, and that's really interesting.

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.

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.

Religion's pretty pervasive in humans. And why it's pervasive in humans is debated a lot. There are indications of things that look like religion in other animals, like chimps doing rain dances, and that sort of thing. Actually, I say that, but there's that and not much else.

Conversation with animals could happen, but I think it would be easier for it to happen with creatures we share a bit more with - those that have been bred to interact with us, like dogs or horses, or ones to whom we have a natural evolutionary link, like chimps and other nonhuman apes. I mean, we do communicate with dolphins and whales, but we're not trying to get to the depths of their understandings. I feel that with animals as different from us as the whales and dolphins, it's likely to work better with us just watching them and trying to figure them out.