Abstract
The current study investigated the role of verbal behavior in the formation of derived comparative relations. We exposed twelve adults to conditional discrimination training with both nonarbitrary and arbitrary stimuli, followed by derived comparative and transformation of function tests using a non-concurrent multiple-baseline design across participants. Additionally, we implemented a think-aloud protocol to assess participants’ verbalizations during derived relations tests. Participants who performed below criterion were exposed to verbal operant training and re-tested, while two control participants received verbal operant training alone. Across four experiments in which several variables were manipulated, only two participants passed derived comparative tests after conditional discrimination training and none passed transformation of function tests. Following verbal operant training, twelve participants (10 experimental and 2 control) passed all tests and emitted a high percentage of correct vocalizations. These results suggest that participants’ verbal behavior played an important role in successful derived relations’ performance.