A Procedure for the Assessment of Individual Differences in Relational Discrimination Behavior in the Pigeon (Columba livia)

Raven’s progressive matrices (RPM) is a nonverbal intelligence test that examines abstract reasoning by asking subjects to correctly complete a stimulus matrix where transformations between stimuli in the matrix follow one or more relational rules. While this test has been used since 1936, and has been modified to accommodate a variety of humans, this is the first adaptation for non-human animals. We trained pigeons on a task in which the complexity of the rules could increase progressively. Pigeons initially were trained on one rule, and if discrimination reached criterion performance, were tested on novel exemplars to assess relational control. After learning one rule, some pigeons were trained on a second rule, followed by transfer tests. We chose pigeons because of their previous success in abstract and relational rule learning. Pigeons varied in how many rules could be learned and in how well they could transfer learning to novel images, indicating that this test can measure individual differences in learning abstract properties such as stimulus relations. One pigeon successfully learned and transferred two relational rules, and was tested on a matrix combining both rules together. In the future, our modified RPM procedure could be used to investigate abstract reasoning across species.