At the turn of the century an American explorer, Robert Garner, used bribes of corned beef to try to train a pet chimp to say words such as '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 similar attempts by scientists. All fell at the first hurdle, however, as it was realised that apes lack the throat muscles and voice-box needed to reproduce human speech.
In the 1960s and 1970s, researchers took a different tack: instead of teaching apes to vocalise, they tried to get them to communicate using artificial languages made up of hand signals or plastic symbols. They found that chimpanzees could be taught 'words' for several hundred objects and actions. They could also be trained to follow simple grammatical rules. But the chimps never showed any fluidity or spontaneity in their communication. Some invisible barrier seemed to remain.
In the 1970s, biologists such as Dr Louis Herman, director of Hawaii's Kewala Basin Marine Mammal Laboratory, began to wonder whether people had been working with the wrong animal. A chimp's brain is less than one-third the size of a human's, but a dolphin's is almost the same size. Furthermore, dolphins were known to have their own sophisticated 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 such as Dr John Lilly, who as early as 1961 was claiming that slowed-down recordings of dolphins sounded like slurred human speech. Even more taken by the idea - and with the deep pockets to bankroll research - were the military.
For decades, both the Russian and US navies have made use of dolphins to do jobs such as patrolling defence installations, looking for mines and locating enemy frogmen. During the Vietnam War, the US Navy flew out dolphins to work in Cam Ranh Bay. They were also used to guard Persian Gulf oil platforms during the Iran-Iraq war in 1987.
It is even believed that deep-diving species, 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 at his laboratories in Hawaii. He says his aim has been simply to use communication as a tool for exploring the cognitive capabilities of dolphins. Until very recently, he has concentrated on teaching them 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.
He began his study with two female bottlenose dolphins, Ake and Phoenix, developing a different communication system for each. For Phoenix, Herman developed a language of electronic whistles played through underwater loudspeakers. He created a vocabulary of more than 50 words, including the names of objects such as a 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 worked equally well.
The training method was simple. The dolphins were taught to touch an object with their noses when they heard or saw its name being signalled. Each time they would be rewarded with fish. After seven months the dolphins had learnt 20 words, including a few commands. Herman began to combine words into sentences to see if the dolphins would understand.
The trainer would sign a sentence such as 'Ake-hoop-fetch-gate', and the dolphin would have to grab a hoop from among the many objects floating in the tank and carry it to a position between two posts. Herman found that the dolphins could not only follow commands up to five words long, but 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.
To show that the dolphins understood what was being said, rather than responding blindly to a set signal as if doing a circus trick, Herman tested their reactions to new sentences. In an experiment in which combinations of commands were tried for the first time, the dolphins reacted correctly in more than 80 per cent of the cases. This result was better than might have been expected of a two-year-old child.
Of more interest were the dolphins' creative responses 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 found the same solution of swimming over to the jet and jerking their heads through it, sending a spray of water flying. On another occasion, Ake was asked to put a ball in a basket when the ball was 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,' Dr Herman argues, 'but these results clearly show that dolphins are capable of some kind of mental representation. Words can have a real meaning for them.'
The most stunning example of the dolphins' creativity has come in the last few months. As training has progressed, Herman has been gradually introducing them to an ever more abstract and ambiguous vocabulary. Recently, they were taught symbols that stood for 'create a behaviour' and 'do this activity in tandem'. In January, the two commands were combined to see how the dolphins would react. When their trainers gave the signals, the two dolphins joined up in the centre of the pool and swam around for a while. Then, simultaneously, they leapt into the air, spitting water as they did so. 'It was as if they had got together first to plan what they were going to do,' Dr Herman says. 'We are not yet sure how to explain the way they co-ordinated their actions.'
So far, because of his determination to follow a scientifically rigorous approach, Herman has focused only on teaching his dolphins to understand language. The next obvious step is to give them a chance to talk back. He 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,' Herman admits. 'We spent nine months constructing a symbol-board for the pool. When we tried it out, 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.'
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 communication through symbols.
Dr Herman says he, too, would like to begin with new-born dolphins. Now that he has added a male bottlenose to the collection at Kewala Basin, Hawaii, he hopes to have the chance to do this within a few years. The question remains, however, of whether dolphins, chimpanzees or any other animal - even with the best techniques and the earliest of starts - can learn to speak in a sense that is meaningful.
The research done so far shows that animals can both react to and manipulate symbols. There also seems to be genuine understanding taking place in the animals' minds; the symbols come to represent abstract ideas and mental images, just as they do for humans. But it appears that there is something about the human brain, some kind of neural motor, that gives us not just the ability to speak but an inner compulsion to do so. The Dr Doolittle fantasy fails because, while we may want to talk to the animals, we are less able to persuade them that they want to talk to us.-
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