Equivalence class analysis of responding consistent with the relational frame of opposition

We replicated and extended studies showing that contextual cues for matching stimuli from 2 separate equivalence classes control the same derived relations as contextual cues for opposition frames in RFT studies. We conducted 2 experiments with 6 college students. In Phase 1, they received training in a conditional discrimination AB. Then, they received training for maintaining AB with X1 as context, and for reversing the sample–comparison relations of AB, with X2. In Phase 2, X1 functioned as context for matching same‐class stimuli, and X2 functioned as context for matching separate‐class stimuli. In Phase 3, X2 controlled the same derived arbitrary relations as cues for opposition frames in RFT studies. This functional equivalence may suggest that X2 functioned as a cue for opposition frames. In Phase 4, participants matched different stimuli with X2 as context, instead of matching most different (opposite) stimuli. In addition, Different, a cue for matching different stimuli, controlled the same derived arbitrary relations as X2. These results are incompatible with X2 being a cue for opposition frames. Contextual control over equivalence and responding by exclusion can explain these outcomes. The implications of these findings for RFT studies on opposition frames are discussed.