English serves as intermediary language: studies with parrots

The parrot Alex is undoubtedly a star performer among animals in the number of questions he is able to skilfully answer with the use of an intermediary language. When his human partner Irene Pepperberg shows him a paper triangle and asks, " What shape? " - he answers “Three-corner". Being shown five sticks dyed red and asked " What colour? " he says " Rose." Then being asked " How many? " he says " Five." Being shown a purple metal key and a larger green plastic key and asked”Alex, how many? " the parrot says " Two." The same two keys are held up with a different question. " Which is bigger? " The parrot stares, pauses, then says, " Green key." Next is a wooden stick. " What matter? " Again the long pause, again a correct answer: " Wood." Alex is clearly responding to the question itself, as well as to the objects. He understands " different" and " same" and can answer questions about relationships: Show him a blue-dyed cork and blue key and ask, " What's the same? " he will answer, " Colour." Show him two identical squares of rawhide and ask, " What's different? " and he will say, " None." Substitute a pentagon for one square, and he will answer, ” Shape."

The African Grey parrot Psittacus Erithacus has been taught by Pepperberg to use English as the intermediary language. Human language is a non-species-specific code for a bird. Parrots are famous for their capacity to mimic human speech, and they often use human words in relevant context being conditioned (sometimes self-conditioned) to associate definite words with repeatable situations, for instance, to say “Good Bye” when somebody is leaving the room.

Mowrer (1950, 1954) was one of the first to study functional communication in birds under controlled behaviouristic procedures, using standard techniques. He studied mynahs (Gracula religiosa), magpies (Pica pica), crows (species not reported), and several psittacids (budgerigars, Melopsittacus undulatus; a Yellow-headed parrot, Amazona ochrocephala; and a Grey parrot). He used the operant methodology, but although his birds were trained according to principles of association and reward, they were neither socially isolated nor placed in operant chambers for their sessions. Mowrer introduced several different words and phrases, and the reward for all vocalizations was food. The idea was that, after a bird emitted vocalizations with some frequency, it could be trained to produce the utterance only in the original, appropriate context (on the appearance of the trainer), by providing the food only when the vocalization was emitted in such a situation (such as saying " Hello" when the trainer appeared). Mowrer's birds acquired few vocalizations. The use of food rewards that directly related neither to the task being taught nor to the skill being targeted probably delayed or possibly prevented learning. Most likely, birds confounded the label of the object or action to be taught with that of the unrelated food reward (Pepperberg, 1981, 1983).

Pepperberg has treated Alex in a social environment from his early age, like primatologists have done with their bonobos. Alex has been her single subject for many years as he has been involved into social relations, plays and training during nearly all periods of his activity. Alex was trained first to speak the names of objects (‘e.g. “key”, “grain”, “paper” and so on). Whenever Alex named an object correctly, he was praised and then allowed to eat it or to play with it.

The language training tests used by Pepperberg are based on the adaptation of a technique developed by Todt (1975), who found that the Grey parrot learned phrases most quickly from two trainers: One formed a bond with the parrot, the other acted as both a " rival" and a model. For the parrot to gain the attention of its " mate" it had to learn to mimic simple phrases used repeatedly by the model/rival. In Pepperberg's study no one took the role of Alex's mate. Trainers took turns " training" each other to name objects while Alex watched and listened; eventually he joined in. Alex would be in a position that allowed him to see two trainers. One trainer then asked the other, who adopted the role of a parrot, to name an object; if the trainer’s reply was correct, then he or she was praised and allowed to play with the object.

Being trained in this manner during many years - more than twenty up to now- Alex has become the most educated bird in the world. He proficiently uses more than 100 English words correctly to refer to all objects in his laboratory environment that play a role in his life including his fifteen special foods, his gym, the shower, the experimenter's shoulder, and more than one hundred other things. After Alex had learned to use the numbers one to six and had learned that a triangle is " three-cornered" and a square is " four-cornered, " he spontaneously and creatively called a football " two-corner" and a pentagon " five-corner." In tightly controlled experiments Alex was shown many objects in various combinations, and he answered correctly an astonishing number of questions regarding these objects, such as " What object is blue? " " What shape is wood? " " How many are wool? " Since Alex never knows what questions he will be asked next, he must be able to carefully attend to and understand each question, and he must be ready at all times to answer questions regarding anything he has ever learned (Pepperberg, 1983, 1987, 1990, 1999).

Evidence that Alex is capable of understanding and creating sentences comes from his use of some phrases in the context of his living situations. At the outset of his training Alex was unhappy in novel places and consequently spent most of the time in either his cage or his gym, which contained a collection of rods and ropes. When in his cage he was often asked “Wanna go gym? ” and this frequently produced “yes” in reply. After a while he spontaneously uttered the phrase “Wanna go gym” by himself and was immediately carried to it. He then modified this phrase to “Wanna go gym-no” when he was in the gym and appeared to want to leave it. As he gained in confidence Alex would sit on chairs, shelves and a trainer’s knee. During this time he often heard the names of these perches, but he never heard them in conjunction with the phrase “Wanna go”. Despite this constraint Alex started to say phrases “Wanna go chair”, and if he was taken to a different place he responded either with a “No” or with a repeat of the request (see: Pearce, 2000).

Recently Pepperberg and her colleagues included several other Grey parrots into their studies, focusing with them mainly on social and cognitive aspects of communication. Among new birds there are two that were raised in the laboratory, and they are very cooperative. Alex, by contrast, can be far from easy. He may refuse to answer questions, shouting " No! " and turning his back. He may repeat the wrong answer stubbornly or demand some other item: " Want corn! ". When Alex was asked to name one from six objects on a tray the one that was green, he named the other five-everything but the desired answer - and then tipped the tray onto the floor. This may be the reason why he gets " only" 80 percent correct on his tests (see: Kaufman, 1991).