麻豆传媒

Few questions are so guaranteed to enrage and perplex as this: are animals conscious and how can we know? Some 60 years ago, Harvard biologist Donald Griffin and his fellow student Robert Galambos discovered that bats navigate and hunt in the dark using their own personal sonar. At the time, it seemed incredible-how could a bat do something even the military had yet to perfect? But Griffin was only just getting started. Next, at Rockefeller and Harvard universities, he made the case for the thinking bee-in the process pioneering the new field of cognitive ethology. In his book Animal Minds, he argues that even what we consider some of the lowliest of creatures could be conscious. Is such talk idle speculation, or the stuff of proper scientific enquiry? Griffin explained all to Gail Vines.

You say that many scientists are suffering from 鈥渕entophobia鈥� that belittles non-human animals and robs them of any possible claim to consciousness. Why has this happened?

I don鈥檛 really quite know. One origin is the desire for scientific rigour and that鈥檚 very reasonable. Scientists like to study things where they can get reasonably clear and definite answers. But there鈥檚 a great deal of science where we can鈥檛 yet do that though we still investigate the topic. Yet somehow when you mention animal consciousness, there鈥檚 this feeling that because we don鈥檛 see how to get perfect evidence immediately, it鈥檚 a waste of time to try to get any evidence. That鈥檚 what I think is mistaken. This area has been neglected in a special way, unlike other difficult, challenging problems. It鈥檚 an area in which it is quite possible to study and learn significant things.

But why should we need to know whether animals are conscious?

Scientifically I think it matters if we want to understand animals and how they evolved. And of course there are much broader moral and ethical implications beyond science that I am not qualified to address. About as far as I would go is to say that if your moral and ethical decisions are based on the assumption that animals are not conscious, that is getting questionable.

You鈥檙e fielding critics from both philosophy and science at the moment.

Yes. Many philosophers feel that humans are unique or so enormously different from the other animals that animal minds are simply uninteresting. The scientists, on the other hand, just have not yet caught up with the opportunities. All I can say is that as a biologist I do find them interesting. This is a difficult, challenging area but science thrives on difficult, challenging areas. Look at astrophysics. If we required perfect proof of everything, there would hardly be any astrophysics. I do not see in the foreseeable future how we can get perfect evidence about animal minds, but neither do I see how we鈥檙e going to get perfect evidence about what happened before the big bang.

Wittgenstein famously remarked that if a lion could talk we couldn鈥檛 understand him. Was he wrong?

In a way. We can begin, perhaps not perfectly, to understand-we鈥檝e already learned a little bit about what vervet monkeys mean by their alarm calls. Not a great deal, but it鈥檚 not zero either, and it鈥檚 worth pursuing. I have a feeling that if scientists really worked at it as hard as they work on other problems, they鈥檇 soon discover that there are many animals, like Irene Pepperberg鈥檚 African grey parrot (麻豆传媒, 15 January 2000, p 40), who mean what they say.

Didn鈥檛 you have similar problems when you published your work on echolocation and bats? Weren鈥檛 they sceptical-to say the least?

It was a real surprise at the time, in the early 1940s. There was one famous incident where a leading physiologist went over to Robert Galambos, seized him by the shoulders and shook him and said: 鈥淵ou don鈥檛 really mean this, do you?鈥� He moved on to other work, but I continued to study bats at Cornell, and then bird navigation, particularly at Rockefeller University. I鈥檝e always thought of myself as a comparative physiologist with a special interest in how animals use their sensory systems to find their way around.

You were a student at Harvard, the stronghold of behaviourism in the US. How on earth did you get interested in how animals think and feel?

I鈥檇 always been sceptical about behaviourism because it says you can explain behaviour only in terms of stimuli and responses, and claims that it is unscientific to inquire about subjective feelings and conscious thoughts. So I was never quite convinced, although I was certainly subjected to a great deal of it at Harvard-I just thought, I have thoughts and feelings and all this behaviourist argument says that they鈥檙e not important either.

So you thought there was no way to gather valid evidence on subjective experiences?

Initially. What began to make me think otherwise was when I was at the Rockefeller University in the 1970s when philosopher Thomas Nagel came to visit. He was writing a paper that later became quite well known, called 鈥淲hat is it like to be a bat?鈥�. He asked me what I thought about this and I gave the usual answer that I thought bats might have some thoughts but I could see no possible way to find out. That got me thinking and suddenly a little light bulb went on. I realised, hey, how do we make inferences about other human thoughts and feelings? We do it primarily through communication of one sort and another, not just formal language but non-verbal body language and so on. That was a brand new idea to me. I began to think, well now, it isn鈥檛 impossible for a scientist to gather information about animal awareness. We can use animal communication as evidence of what the animals are thinking or feeling.

You coined the word 鈥渃ognitive ethology鈥�. What is that exactly?

Yes, I think so, in a book published in 1976 called The Question of Animal Awareness. Now I won鈥檛 swear that nobody else used anything like it before, but it was certainly relatively novel in the area of work on ethology and animal behaviour. When I first suggested this term I was hoping to emphasise that animal behaviour cannot be adequately understood without considering animal cognition-the way animals reason, think and process information about the world.

Now you鈥檙e pushing it further when you say we can study not only the reasoning processes but animals鈥� subjective experiences?

I think so. I鈥檓 not alone here. Marian Stamp Dawkins at Oxford University is one of the leading people. We all have our different approaches and we don鈥檛 all agree completely about these things, but there is certainly a trend, though there鈥檚 a great deal of resistance, which I find really entertaining. One strategy is to discredit by exaggeration, for instance, the cover of one popular weekly magazine showed a dog with a balloon rising from his head and inside the balloon was 鈥淓=mc²鈥�.

While some people might be willing to concede that apes are conscious in some way, you argue that consciousness could be much more widespread than we imagine.

Yes. This is an extremely difficult field of science and one where we know very, very little and should avoid dogmatic statements. It鈥檚 a curious point that I鈥檝e made in all my books that in the face of very weak evidence we scientists tend to make very strong, negative statements-no animal does this, animals can鈥檛 do that and so on-when we really don鈥檛 know. I think we should have an open mind. Incidentally, when I talk about animals being conscious I do not mean that they have anything like the complexity and richness of human consciousness. But I don鈥檛 think, at this stage we can rule anything out.

But you argue that bees are thinking creatures and might even be conscious ones?

Karl von Frisch鈥檚 discovery of the dance communication system of honeybees, the waggle dances, has greatly impressed me. That was a real shocker because in the late 1940s and early 50s we had all been brought up to think that insects just don鈥檛 do anything remotely like this. If it hadn鈥檛 been somebody as respected as von Frisch I think we just wouldn鈥檛 have believed it-and in fact we didn鈥檛 believe it at first. Bill Thorpe at Cambridge and I wanted to see it for ourselves so we got our own bees and sure enough von Frisch was right. So that widened my perspective a great deal. I just didn鈥檛 think insects or any other animals, other than perhaps mammals, could possibly do anything like that, and here was good solid evidence that one insect at least does.

So you reckon understanding the communication systems of other animals can give us a window into their mental worlds?

Yes. I do believe that very strongly. If we were deprived of any sort of communication from other humans, we鈥檇 be very hard put to make much inference about their thoughts and feelings. Now that鈥檚 not a terribly strong intellectual argument, because you could always say, well, that鈥檚 true of one species, humans, but not of any other. Yet to a biologist that鈥檚 a little suspicious. I鈥檓 not saying consciousness is tightly linked to communication: you can be conscious without communicating, for instance. But all the same, it鈥檚 the best sort of objective evidence that I can think of that鈥檚 available to scientists.

Have any other creatures got anything comparable to the honeybee dances?

In the realm of natural communication the honeybees provide the clearest example. Another strong example comes from the study of vervet monkeys whose alarm calls have been shown to convey the identity of specific predators-snakes, eagles, or leopards. But there might be others if we begin to look for them. In studies of animal communication, scientists have usually stuck to relatively simple subject matter such as aggression or courtship and not wondered what other information might be being conveyed. There is beginning to be a little work along those lines but it鈥檚 very, very difficult to get convincing evidence. Even von Frisch took years to notice the full complexity of his dancing bees, though he鈥檇 been studying them intensively. I鈥檓 trying to point out opportunities rather than making definite claims.

So even the relatively simple brain of a honeybee might possibly鈥�

But it isn鈥檛 simple. Recent work on the honeybee鈥檚 brain shows that it is very small but very complicated. The nerve cells tend to be smaller than human ones too, so in terms of numbers of possible interactions there鈥檚 a quantitative difference-but not, I think, a qualitative one.

But surely insect behaviour is overwhelmingly genetically hard wired, almost robotic?

We make that assumption, and link genetic programming with lack of consciousness, and yet we don鈥檛 actually know whether that鈥檚 true. We鈥檙e genetically programmed to sneeze, and yet we鈥檙e conscious of it. What鈥檚 more, as we know ourselves, learned behaviour is not necessarily conscious. An experienced cyclist doesn鈥檛 have to think about how to steer the bike. In any case, honeybees do a lot of learning. They have to learn each day where the food is and then communicate it, for example. So the idea that they鈥檙e rigid and little mechanical-one of my colleagues at Cornell speaks of it as looking at honeybees as though they were flying toasters-is misleading. They鈥檙e actually quite complicated. Though it鈥檚 very limited compared with what mammals do, it鈥檚 not completely different. It seems to me, more likely than not, that there is some sort of continuum extending from the mental world of bees to us.

Will we ever be able to tell a creature is conscious by examining its nervous system?

We may end up with neurological markers of consciousness, a particular pattern of activity, say, or even a particular neurochemical. But we鈥檙e nowhere near that yet. If you ask what is there about central nervous systems that makes consciousness possible, we don鈥檛 know. But the sort of processes that the neuroscientists believe may be the basis of consciousness are totally independent of the size and shape of a particular nervous system. Granted, there鈥檚 probably some minimum size necessary, but honeybees have brains with thousands if not millions of neurons.

But what鈥檚 the point of being conscious? Why might it have evolved in animals?

I think it鈥檚 an efficient way to use the central nervous system, especially to cope with unpredictable challenges. It鈥檚 easy to contest this idea, because anything an animal is observed to do can be interpreted in a behaviouristic fashion without assuming any consciousness. After all, humans can do quite complicated things without consciousness. So the argument goes, whatever an animal does, it might be done without consciousness. But I think it is possible, plausible even, that consciousness is a more efficient way to use a brain, a central nervous system. It probably doesn鈥檛 have to be packaged in a particular part of the animal. I don鈥檛 know how to test it scientifically yet. But, of course, if it is an efficient way to use a brain, then it would have obvious adaptive advantages.

And what might bees be conscious of? Might they have fantasies and dreams?

Yes, but of course we are even more ignorant about that. Studies of REM sleep, indicate that dreams are present in other mammals. I鈥檓 not quite sure about the evidence with birds but dreaming is certainly not limited to humans. There are indications that sleeping dogs seem to be running or even copulating. Who knows? My feeling is that these are challenging questions for scientists and not hopelessly impossible ones that ought to be taboo.