Language-naive chimpanzees (Pan troglodytes) judge relations between relations in a conceptual matching-to-sample task.

Abstract

Three chimpanzees with a history of conditional and numeric token training spontaneously matched relations between relations under conditions of nondifferential reinforcement. Heretofore, this conceptual ability was demonstrated only in language-trained chimpanzees. The performance levels of the languagenaive animals in this study, however, were equivalent to those of a 4th animal-Sarah-whose history included language training and analogical problem solving. There was no evidence that associative factors mediated successful performance in any of the animals. Prior claims of a profound disparity between language-trained and language-naive chimpanzees apparently can be attributed to prior experience with arbitrary tokens consistently associated with abstract relations and not language per se. Early reports by some investigators indicated that language-trained chimpanzees differed profoundly in their problem-solving skills from chimpanzees who had not had such training (D. Premack, 1983a, 1983b, 1984, 1986; Savage-Rumbaugh, 1986). Language-trained chimpanzees solved conceptual problems that language-naive chimpanzees failed. D. Premack's language-trained animals, for example, reportedly were superior to the language-naïve animals on problems that required reasoning about relations between relations but that could not be solved merely on the basis of correspondence of physical features. The discrepancy between language-trained and language-naïve chimpanzees reported by D. Premack was based originally on the performances of seven African-born chimpanzees raised from infancy by human caregivers; three of the seven had received language training and four had not. Premack argued that the disparity in performance between these two groups of animals on such tasks could not be attributed to either age differences or their relative test sophistication (cf. D. Premack, 1984). Rather this profound disparity could be attributed only to whether or not an animal had received language training as originally described by D. Premack (1976). Short strings of rule-governed plastic words formed the physical basis of this language, which the chimpanzees used in both comprehension and production. See

Concept Learning in Animals

“…Spontaneous analogical matching of relations between relations by chimpanzees, under conditions of nondifferential reinforcement, was reported by Thompson, Oden, and Boysen (1997). One of the animals in the study was Sarah, whose analogical capacities have already been described.…”

“…So, why did these young chimpanzees fail to categorically match analogical relations? Perhaps they lacked requisite exposure to the presumed facilitative effects of symbol training and labeling on the relational recoding that was experienced by other chimpanzees and children (e.g., Rattermann & Gentner, 1998;Thompson et al, 1997).…”

Categories as paradigms for comparative cognition

“…Such relational requirements have been tested in a conceptual matching-to-sample task (a modified version of an analogy problem) proposed to chimpanzees with previous training with conditional and numerical tokens (Thompson et al, 1997). Four of the five subjects were successful at conceptually matching relations between relations, even though they were provided with no explicit training via differential feedback on each trial.…”

Successive two-item same-different discrimination and concept learning by pigeons

“…After learning this discrimination, the degree to which this behavior transfers to novel situations having same and different relations is taken as evidence of concept formation. Using this choice task, it has been found that pigeons, parrots, rhesus monkeys, baboons, and chimpanzees are capable of learning and applying a S/D concept across a wide variety of simultaneously presented visual elements (Bovet and Vauclair, 2001;Cook, 2002a,b;Cook et al, 1995Cook et al, , 1999Cook and Wixted, 1997;Katz et al, 2002;Pepperberg, 1987;Thompson et al, 1997).…”