FORMATION OF TRANSITIVITY IN CONDITIONAL MATCHING-TO-SAMPLE BY PIGEONS

Four homing pigeons were trained over 5 months in a zero-delay, ''arbi trary'' matching-to-sample procedure with sample and comparison stimul i presented on any of three response keys. Birds were also required to complete a fixed-ratio 10 requirement on both sample and comparison s timuli to terminate their presentation. The procedure resulted in the establishment of relations that were not specifically trained and that can be characterized by the property of transitivity in a stimulus eq uivalence context. This result was in contrast with the findings obtai ned from most previous research with nonhuman subjects.