Abstract
Separate groups of pigeons learned the same three sets of sample-comparison relations across two phases of conditional discrimination training. For one group, that training consisted of multiple-sample, single-comparison (A–X, B–X) matching-to-sample followed by a second matching task in which two of the original samples were matched to new comparisons (A–Y). For the other group, initial training consisted of single-sample, multiple-comparison (A–X, A–Y) matching-to-sample followed by a second task in which two of the original comparisons were matched to new samples (B–X). Both groups were then tested on the same set of derived sample-comparison relations (B–Y). Transfer to these derived relations was evident following the multiple-sample, single-comparison training sequence but not following the single-sample, multiple-comparison sequence. Apparently, the emergence of new conditional relations in pigeons depends upon the order in which the component conditional discriminations are learned—a result predictable from Hull's (1939) analysis of secondary stimulus generalization.