Note on the Calibration of Inter-Species Successive Discrimination Reversal (SDR) Performance Differences: Qualitative vs Quantitative Scaling

Abstract

Two different approaches to the calibration of inter-species SDR performance differences that have emerged over the past decade are discussed. One, the discontinuity hypothesis, proposes a qualitative dimensional shift across vertebrates, with a two-category scale based upon the presence or absence of error reduction on SDR tasks. The other approach, the continuity hypothesis, argues for a quantitative dimensional shift across species, with a scaling of inter-species performance differences in terms of absolute scores. Important directions for future research are suggested.