Verbal Stimulus Control and the Intraverbal Relation

Sundberg (2016) taught adults to answer questions that had two-part cues. An example cue was “Name a red—fruit.” The team wanted both parts of the cue to control the answer. They tracked whether new questions with the same cue parts created brand-new answers.

The first word in the cue stole all the power. The second word was mostly ignored. Because of that theft, new questions did not bloom into fresh answers. The hoped-for flexible intraverbal web never showed up.

Cariveau et al. (2022) ran the same layout and saw the same shadow effect. Their data line up with Sundberg like a direct twin.

Vedora et al. (2015) worked with toddlers who had autism. They compared single-word cues against two-word cues and saw little difference. That outcome seems softer, but the kids were younger and the goal was receptive language, not intraverbal splits.

Shillingsburg et al. (2019) took the opposite road. They wove mastered tacts and listener trials into intraverbal drills for kids with ASD. Every child then gave brand-new intraverbal answers. Their positive result shows the shadow effect can be beaten with extra verbal groundwork.

If you run intraverbal programs, do not trust that a two-part cue will be treated as two cues. Probe each part alone. If the learner only answers to the first part, add brief tact or listener warm-ups until both parts gain control. This quick check saves weeks of stalled progress.