Effects of undesirable, competing behaviors on the generalization of adaptive skills. A case study.

One young adult with intellectual disability learned to say polite words instead of swearing. The team first taught the new words in a quiet room. Then they tested if the skill moved to a room that used to trigger cursing. They ran the test four times, turning the trigger on and off.

The trigger was a staff member who had heard the cursing many times before. His presence alone had become a green light for swearing. The study asked: will the new polite words win, or will the old trigger take over?

When the "cursing trigger" staff walked in, the polite words almost vanished. Swearing shot back up, even though the skill still worked fine with other staff. The old stimulus control was stronger than the new skill.

Each time the trigger left, polite words returned. The skill had not generalized because competing stimulus control blocked it.

Haddock et al. (2020) later pooled 30 years of data and confirmed the 1989 warning: always test what stimuli already control problem behavior. Their review shows that brief competing-stimulus assessments predict later treatment failure.

Tiger et al. (2021) added prompting plus response blocking to the same assessment format and finally beat automatically maintained behavior. Their tweak extends the 1989 idea: you can still use competing items, but add active help if the behavior is strong.

Leung et al. (2014) showed the flip side with preschoolers: skills only generalized after teachers were told the exact plan. Together these papers say the same thing—environmental cues decide whether new skills live or die.

Before you run a generalization probe, list the people, places, or objects that already pull problem behavior. Run a quick competing-stimulus assessment if you need data. Then either remove or re-train those cues, or add prompts and response blocking. One extra five-minute check can save weeks of re-teaching.