Maintenance of Equivalence Classes and Transfer of Functions: The Role of the Nature of Stimuli

The present study established three equivalence classes (each comprising nonfamiliar stimuli and a facial expression of emotion) and verified transfer of function among equivalent stimuli with a semantic differential in order to investigate stability over time of both equivalence classes and of transfer of functions. Nonfamiliar stimuli were abstract pictures and the emotions of the facial expression were happiness, anger, and neutrality. A control group evaluated the familiar stimuli from each class. Sixteen college students attained criteria for equivalence class formation. Their evaluations of the nonfamiliar abstract stimuli were similar to the evaluation that control group made of the facial expressions. Thirty days later, participants from the experimental group were resubmitted to the equivalence tests and to the semantic differential device. During maintenance tests, 11 participants attained criterion for maintenance of the happy class, 8 participants for the neutral class, and 6 for the angry class. Participants who maintained performance on equivalence tests maintained performances on the semantic differential device. Participants who failed on maintenance tests also deviated from previous performances on the test for transfer of function. Results indicated valence of stimuli influenced stability of equivalence classes and transfer of function.