Impact of language on behavior treatment outcomes
Single-language FCT can break at home for bilingual families—build both languages into the plan from day one.
01Research in Context
What this study did
Neely et al. (2020) worked with three Spanish-English bilingual children with autism. They taught each child a new way to ask for things using English only. Then they watched what happened when the family spoke Spanish at home.
What they found
Two of the three kids lost their new English requests when Mom spoke Spanish. Problem behavior came back. One child switched to Spanish on his own and kept the gains. The team had to add Spanish words for the other two to stop the slide.
How this fits with other research
Banerjee et al. (2022) ran almost the same study and got the same result. They added a 'say it again' step and saw even stronger gains. Blair et al. (2025) looked at 34 FCT papers and still found the biggest wins in school, not home. Suess et al. (2020) showed you can cut the slide short by first teaching in a 'clean' Zoom room with no history of payoff for problem behavior. Together the four papers say: teach the mand in every place and every voice the child hears, or expect a comeback.
Why it matters
If you run FCT in English only, you are gambling. Check the home language during intake. Probe the child in Spanish and English before you start. Add both to the plan up front, or budget extra sessions for the 'oops' resurgence you will likely see later.
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02At a glance
03Original abstract
Resurgence of problem behavior following effective functional communication training (FCT) can occur if the functional communication response contacts extinction. For children from dual-language households, extinction may unintentionally occur due to language variations among communication partners. In the current study, the experimenters evaluated the effect of language on FCT outcomes. Participants were 3 children with autism who engaged in problem behavior and whose parents reported Spanish as the primary home language. The experimenters conducted FCT in the English language followed by probes in the Spanish language. Results suggest that functional communication responses (FCRs) learned in the first language (English) may lead to resurgence of problem behavior when English FCRs do not contact reinforcement in the untaught language (e.g., Spanish). Two of the participants required additional teaching in the secondary language (Spanish), while the third participant eventually emitted Spanish FCRs in the Spanish condition without explicit teaching.
Journal of Applied Behavior Analysis, 2020 · doi:10.1002/jaba.626