Using 4 adult and 3 young chimpanzees, the investigators trained their subjects to respond to one of two very different objects which matched a third object. After this habit was learned, the subjects were tested on a number of entirely new objects to determine the extent to which the matching response had become generalized. The results indicated such generalization to occur in all subjects. Three hypotheses to account for such learning are discussed: (1) the "learning mechanism," (2) the "perception mechanism" and (3) the "abstract generalization mechanism." The writers conclude that their data do not indicate the primacy of any one of these three approaches. 20 references. (PsycINFO Database Record (c) 2006 APA, all rights reserved)