The Alex Studies: Cognitive and Communicative Abilities of Grey Parrots
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Can a parrot understand complex concepts and mean what it says? Since the early 1900s, most studies on animal-human communication have focused on great apes and a few cetacean species. Birds were rarely used in similar studies on the grounds that they were merely talented mimics--that they were, after all, "birdbrains." Experiments performed primarily on pigeons in Skinner boxes demonstrated capacities inferior to those of mammals; these results were thought to reflect the capacities of all birds, despite evidence suggesting that species such as jays, crows, and parrots might be capable of more impressive cognitive feats.
Twenty years ago Irene Pepperberg set out to discover whether the results of the pigeon studies necessarily meant that other birds--particularly the large-brained, highly social parrots--were incapable of mastering complex cognitive concepts and the rudiments of referential speech. Her investigation and the bird at its center--a male Grey parrot named Alex--have since become almost as well known as their primate equivalents and no less a subject of fierce debate in the field of animal cognition. This book represents the long-awaited synthesis of the studies constituting one of the landmark experiments in modern comparative psychology.
labels. He did more than associate a particular object and a particular vocalization, but had not yet acquired peri-referential use. He used a symbol—a vocal utterance—to indicate the presence of or seemingly to request not one particular item, but a particular type of item (see below). He used vocalizations to transfer information to his trainers about an object, but we could not yet determine if he was commenting on the object or requesting it. He did seem to have some concept of each modiﬁer
whose labels are also made of arbitrary patterns—‘‘color’’ and ‘‘shape.’’1 The ability to form these classes or relationships is not elementary, even for humans: Children who learn that one set of objects is ‘‘green’’ and another is ‘‘red’’ may still not understand that there exists an overall concept of ‘‘greenness’’ or ‘‘redness’’ that can be generalized to novel objects (Rice 1980). According Does a Parrot Have Categorical Concepts? / 54 to de Villiers and de Villiers (1978), acquiring both
moreover, showed that language training does not improve a child’s ability to learn concepts such as ‘‘color’’ (as opposed to the labels for individual colors) if the child has not already reached a certain stage of development. Subsequent studies (review in Mandler 1990) support the idea that children form many concepts well before they acquire language.3 What is not easily resolved, however, is how complex a concept must be before its comprehension might indeed require a form of language
recognition that a pair of novel objects may or may not have something in common. Alex’s scores suggest that he responded not to speciﬁc instances of color, shape, and material (particular sets of items or classes of stimuli), but rather on the basis of abstract concepts, even when the particular attributes of each object were unfamiliar and the speciﬁc combinations of color, shape, and material for each item, as well as for the pair, had never before been seen on a test. Can a Parrot Respond to
reproduce human syntax, has many of the other capacities. In contrast, lesser species not only cannot reproduce human syntax, but lack other capacities as well. David Premack, Cognitive Processes in Animal Behavior (1978:423–424) The ability to comprehend relational as well as absolute concepts (e.g., answer ‘‘Is A bigger than B?’’ in addition to ‘‘What color is A?’’) is frequently used to compare intelligence across species (Premack 1978; Thomas 1980, 1996). The rationale is that relative