Carter Daniels


Transitive Inference (TI) is shown when after being told that A is better than B and B is better than C, one can answer the question, what is better A or C (in which A, B, and C are arbitrary stimuli). To avoid end-point effects (A is always better and C is never better) and provide a nonverbal task than can be used with young children and animals, the task has been expanded to 5 terms (i.e., A+B-, B+C-, C+D-, D+E- in which + means choice is reinforced and – means not reinforced). TI is found when subjects choose B when given a choice between B and D. Interestingly; TI effects have been shown in many nonhuman animals including pigeons. Several noncognitive, associative theories that have been proposed to explain TI effects have failed to account for the variety of conditions under which TI effects have been found. One cognitive account of TI performance is that organisms are able to form a mental representation of the series (A>B>C>D>E).If so, presentation of the pairs of stimuli in a linear arrangement should facilitate TI performance, whereas presentation of the pairs of stimuli in a circular arrangement should not. We trained pigeons on either a linear or circular arrangement of stimuli. Results indicate that pigeons show TI under both conditions suggesting that mental representations of the linear relation among the stimuli are not responsible for TI in pigeons. We suggest directions for future research.