Matching derived functionally-same stimulus relations: equivalence-equivalence and classical analogies

Previous studies have shown that, after being trained on A-B and A-C matching tasks, subjects match not only functionally-same B and C stimuli (stimulus equivalence), but also BC compounds with same-class elements and BC compounds with different-class elements (equivalence-equivalence). Similar performances are required in classical analogies (a : b :: c : d). Therefore, some researchers have argued that equivalence-equivalence can serve as a behavior analytic model for analogical reasoning. Recent studies, however, have shown that compounds with same-class elements and different-class elements have different discriminative (S+, S-) properties. Hence, matching of same discriminative functions may have occurred. The present study aimed to design an equivalence-equivalence test in which the designated correct performances cannot be attributed to a process other than matching functionally-same relations. In Experiment 1, subjects were trained to relate X and Y stimuli to colors and X and Z stimuli to forms. After equivalence was assessed (Y-X-Z), the subjects received an equivalence-equivalence test in which only compounds with same-class elements were used: an XY or XZ compound as sample and an XY and XZ compound as comparisons (e.g., X1Y1-X2Y2/X2Z2). All subjects passed the equivalence-equivalence test. However, as reported by 1 subject, and was later demonstrated in Experiment 2, these equivalence-equivalence tasks could be solved by matching functionally-same stimuli (e.g., Y1 -color-Y2, hence Y1-Y2). Experiment 3 demonstrated that this problem also exists in classical analogy tasks. When given the analogy tasks used by Goswami and Brown (1990), all subjects selected the correct d-term option on the basis of the b-term alone (equivalence). In Experiment 4, the equivalence-equivalence test was further modified to permit differentiation of matching functionally-same relations from matching functionally-same stimuli. All 5 subjects readily matched functionally-same equivalence relations, thus evidenced equivalence-equivalence or analogical reasoning