readings> dolphin speech
Teaching dolphins to
speak - Speech marks the dividing line between humans and animals.
Experiments with animals show just how able - or rather unable - they
are to master this essential skill. Everyone knows about the attempts
with chimpazees, but what about dolphins?
Wouldn't it be wonderful to be able to talk to the animals? To be like Dr Doolittle and chat to them about their hopes and dreams, their wishes and fears.
Not surprisingly, many biologists have shared this ancient fantasy. For nearly a century, sober-minded researchers have been trying to teach apes to speak. More recently, they have tried their luck with dolphins. So far success has been only partial - but the question is whether this is because of some inherent limitation in animals or because scientists have yet to discover the right teaching techniques.
At the turn of the century, there were a host of attempts to teach apes to speak. An American explorer, Robert Garner, used bribes of corned beef to try to train a pet chimp to say words like mama and fire. A wealthy Russian woman brought up a chimp in her home to see if it would pick up language alongside her young son. These amateur experiments inspired at least half a dozen similar attempts by professional scientists during the inter-war years. But all such efforts fell at the first hurdle - it was soon realised that apes lack the tongue, throat muscles and voice box needed to reproduce the sounds of human speech.
In the 1960s and 1970s, researchers took a different tack. Instead of attempting to teach apes to vocalise, they tried to get them to communicate using artificial languages made up of hand signals or plastic symbols. With such techniques they found that chimpanzees could be taught words for several hundred objects and actions. Chimps also could be trained to follow simple grammatical rules. But there was always something stilted about the chimps' "speech". The chimps never showed a fluidity or spontaneity in their communication. Some invisible barrier still seemed to remain.
In the 1970s, biologists such as Dr Louis Herman, director of Hawaii's Kewalo Basin Marine Mammal Laboratory, began to wonder whether people had been working with the wrong animal. Chimpanzees have brains which are less than a third the size of humans, but dolphins have brains which are almost exactly the same size. Furthermore, dolphins were known to have their own sophisticated communication system of whistles and clicks which some suspected might prove to be a true language.
The possibility of teaching dolphins to speak entranced Californian New Agers like Dr John Lilly, who as early as 1961 was claiming that slowed-down recordings of dolphin calls sounded like slurred human speech. But even more taken than New Agers by the possibility of dolphin speech - and with the deep pockets needed to bankroll research - were the military. For several decades, both the Russian and US navies have make use of dolphins to do jobs such as patrolling defence installations, looking for mines and enemy frogmen. During the Vietnam War, the US Navy flew out dolphins to work in Cam Ranh Bay. US dolphins were also used to guard Persian Gulf oil platforms during the Iran-Iraq war in 1987. It is even believed that deep-diving species of dolphins, such as the white Beluga whales used by the Russians and the Risso's dolphins used by the US Navy, have been trained to tag enemy nuclear submarines with electronic bleepers or limpet mines. If dolphins could be taught to speak, this would open up a whole new range of underwater possibilities for navy "black ops" squads.
Working in this charged atmosphere, Dr Herman, the world's leading researcher into dolphin communication, has had to tread a careful line. Herman says his aim has been no more than to use communication as a tool for exploring the cognitive capabilities of dolphins. This has meant that, until very recently, he has concentrated on teaching dolphins to understand human commands under strictly controlled conditions rather than worrying about getting dolphins to talk back or to use language in a more conversational fashion.
Herman began his study with two female bottlenosed dolphins, Ake and Phoenix, using a different communication system with each animal. For Phoenix, Herman developed a language of electronic whistles played over underwater loudspeakers. Using different whistle sounds, he created a vocabulary of more than 50 words, including the names of objects such as hoop, frisbee and surfboard; positions such as bottom and surface; and commands such as jump, spit and swim under. For Ake, Herman developed a gesture language that had a similar vocabulary but which was conveyed by trainers making arm movements at the pool edge. Herman had expected that the dolphins would find the whistle language more natural, but was surprised to find that both languages worked just as well.
The training method was simple. The dolphins were taught to touch an object with their nose when they heard or saw its name being called. Each time they would be rewarded with a titbit of fish. After seven months of training, the dolphins had learnt 20 words, including a few commands. Herman then began to combine words into sentences to see if the dolphins would understand. The trainer would sign a sentence like: "Ake-hoop-fetch- gate", and the dolphin would have to grab a hoop from the many objects floating in the tank and carry it to a position between two posts.
Herman found that not only could the dolphins learn to follow commands up to five words long, but they were sensitive to word order. An impossible command, such as gate-fetch-hoop, would be ignored or prompt the dolphin to tap a "no" paddle, meaning the task could not be done. To show that the dolphins in some way understood what was being said, rather than responding blindly to a set signal as if doing a circus trick, Herman tested their reactions to novel and ambiguous sentences. In an experiment in which combinations of commands were tried for the first time, the dolphins reacted correctly in over 80 percent of the cases. This result was better than might be expected of a two year old human child.
Of more interest were some of the creative responses made by the dolphins when asked to do something puzzling. A running stream from a hose had been named "water" and Herman tried the apparently impossible command of "water-toss" on the dolphins. Both animals independently came to the same solution of swimming over to the jet and jerking their heads through it, sending a spray of water flying. Another time, Ake was asked to put a ball in a basket when the ball happened to be already in it. The dolphin went over, took the ball out, then dunked it straight back in again. "A lot of people try to minimise the thinking abilities of animals but these results show that dolphins are capable of some kind of mental representation. Words can have a real meaning for them," Herman argues.
In just the past few months came the most stunning example of the dolphins' creativity. Gradually, as training has progressed, Herman has introduced his dolphins to an ever more abstract and ambiguous vocabulary. Recently, the dolphins were taught symbols which stood for "create a behaviour" and "do this activity in tandem". In January, the two commands were combined for the first time to see how the dolphins would react. "The two trainers gave the signals and the dolphins joined up in the centre of the pool and swam around for a bit. Then simultaneously, both leapt out, spitting water as they leapt. It was if they had got together first to plan what they were going to do. We are not yet sure how to explain the way they co-ordinated their actions," Herman says.
So far, because of his determination to follow a scientifically rigorous approach, Herman has focused only on teaching his dolphins to understand language. But the next obvious step is to give them a chance to talk back. Herman hopes soon to provide the dolphins with a display board of symbols on which they can tap out messages to their trainers. "However we are having some problems with that," admits Herman. "We spent nine months constructing a symbol board for the pool. But when we tried it, it lasted about two weeks. It just wasn't dolphin-proof. Building a board is still a goal. But the funding is one thing we have to work out," he says.
Another step would be to start training dolphins at an earlier age. Researchers, such as Sue Savage-Rumbaugh working with pygmy chimpanzees at Georgia State University, have found that adult chimps struggle to learn speech, but a new- born chimp will rapidly develop a vocabulary of several hundred words. Young brains are more plastic and so find it easier to become attuned to the skills involved in symbolic communication. Herman says he too would like to begin with new-born dolphins. Now that he has added a male bottlenosed to the collection at Kewalo Basin, he hopes to have this chance within a few years.
The question remains, however, whether even with the best techniques and the earliest of starts, dolphins, chimps or any other animals can learn to speak in any sense that is meaningful. The research done so far shows that animals can both react to and manipulate symbols, performing as well in tests as a two year old child. It seems also that there is genuine understanding taking place in the animal's mind - the symbols come to represent abstract ideas and mental images just as in humans. But the missing ingredient seems to be fluency. The use of language never flows as easily, indeed unstoppably, as it does in humans. It appears there is something about the human brain, some neural motor, that gives us not just an ability to speak but also an inner compulsion. The Dr Doolittle fantasy fails because while we may want to talk to the animals, the difficulty is in persuading them to want to talk to us.