Assessment and treatment of automatically reinforced self‐induced emesis

The team worked with a preschooler who made himself vomit for no outside reward. The behavior ran on its own sensory payoff.

They used an ABAB reversal design. In A phases staff blocked every vomit attempt. In B phases they blocked only half.

Trainers scored how well staff followed the plan. 100% blocking meant no vomit got through. 50% meant half still happened.

When blocking was perfect, the child stopped vomiting. When blocking dropped to half, vomiting came right back.

Partial blocking acted like no blocking at all. The behavior needed total extinction to shut down.

DeWitt et al. (2024) saw the same all-or-nothing rule. In their lab, withholding reinforcement only worked when it was complete. Partial extinction let problem behavior surge back.

Robertson et al. (2013) looked like they disagreed. Parents kept rewarding both requests and problem behavior, yet problem behavior still fell. The twist: they added functional communication, giving the child a new, easier way to get the same payoff. Wunderlich did not give an alternate route, so extinction had to be 100%.

DeLeon et al. (2003) also found an odd automatic reinforcer—wheelchair movement. Like Wunderlich, once they removed the sensory payoff the behavior dropped, but they paired it with teaching a request. Together these studies show: if you cannot offer a replacement skill, you must block every single response.

If a client’s behavior feeds only on its own sensation, halfway plans waste time. Either teach a new way to get that feeling, or commit to blocking every instance. Check your treatment integrity data daily; anything below 100% tells you the behavior will bounce back.