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.

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.

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.

Humans are particularly interesting; our culture is incredible, there's no doubt about that. In many respects, no other species matches ours. But in quite a few respects, they do, and that can help us, perhaps, to better understand our own culture. We look at the ways humans are similar to other animals, and at the ways they differ, rather than just saying, "We have culture and you don't."

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.

I never thought of that one, that linguistics could be driving cultural things. There are some thoughts that that does happen in humans, that languages have different characteristics and that influences in some ways how different groups behave, and I suppose it might in whales.

Studying the behavior of large whales has been likened to astronomy. The observer glimpses his subjects, often at long range; he cannot do experiments, and he must continually try to infer from data that are usually inadequate.