Language-naive chimpanzees (Pan troglodytes) judge relations between relations in a conceptual matching-to-sample task.
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 language-naive 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.
Thompson
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RK
Department of Psychology, Franklin and Marshall College, Lancaster, Pennsylvania 17604-3003, USA. r_thompson@acad.fandm.edu
Oden
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DL
Boysen
S T
ST
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D003213:Conditioning, Psychological / Q000502:physiology*; D007802:Language; D002679:Pan troglodytes; D013647:Task Performance and Analysis