The Alex Studies: Cognitive and Communicative Abilities of Grey Parrots
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.
paradigm) would rarely live long enough to learn the task in question (Bandura 1971a); they posited similar bases for cultural learning in humans. They proposed that ‘‘provision of models not only serves to accelerate the learning process, but also, in cases where errors are dangerous or costly, becomes an essential means of transmitting behavior patterns’’ (Bandura 1963:54). Other aspects of modeling theory devolved from these same researchers’ efforts to devise procedures to enable humans to
probably ﬁts instead into a simpler category not merely causes confusion and miscommunication among scientists, but also may prevent us from determining the animals’ actual abilities. We may, for example, settle for describing the simplest behavior if we give such behavior the most complex of labels, and thus miss the full level of competence the animal might demonstrate. I emphasize, however, that by providing these deﬁnitions, by using a human standard for the term ‘‘referential,’’ and thus
‘‘matter,’’ nor to choosing physically between only two objects that were similar to or different from a sample (Pepperberg 1987a). The design of the task ensured that Alex would have to respond on the basis of same/different rather than on the basis of a simpler alternative. His responses on tests were unlikely to be based on absolute physical properties or on his having learned the answer to a given pair, because the number of possible permutations of question topic, correct response, and
manner as all other items used in training and testing, we avoided undue emphasis on quantity. Note that Matsuzawa (1985) also presented objects by hand in his numerosity study on the chimpanzee. Tests were carefully designed (see Pepperberg 1987b). Alex was never tested on exactly the same items used in training. Even for familiar items (corks or wood), test queries always involved pieces of To What Extent Can a Parrot Understand and Use Numerical Concepts? / 102 somewhat different sizes or
in Kamil 1988). For speciﬁc experiments, however, we can make operational deﬁnitions that characterize both cognitive behavior and tasks that facilitate cross-species comparison of such behavior (Pepperberg 1990a). Generally, cognition is viewed as an organism’s ability to make a decision by evaluating, or processing, current information based on some representation of prior experience (see, e.g., Kamil 1984). The supposition is that the organism does not react mindlessly to environmental