Establishing the Transformation of Motivating Operations Across Mands and Tacts for Preschoolers With Developmental Delays

In 2 studies, we tested the effects of multiple exemplar instruction (MEI), using rapidly rotating mand and tact opportunities under relevant motivating conditions, on the transformation of motivating operations (MOs) across mands and tacts for sets of adjective-object pairs. The design for both studies was a delayed multiple probe across participants, using pre- and postintervention tests of untaught mand or tact functions. Two 3-year-old children with developmental disabilities participated in Experiment 1, and 5 4-year-old males with developmental delays participated in Experiment 2. At the outset of the study, none of the participants demonstrated both mand and tact responses for untaught functions. After MEI, untaught adjective-object functions for mands or tacts emerged for all children in both experiments, suggesting that the transformation of MOs is a verbal behavior developmental cusp. Our findings support Skinner's notion that mand and tact functions are acquired separately, but later join as a function of experience.