Mutual exclusivity and exclusion: Converging evidence from two contrasting traditions.

LeFrancois et al. (1993) wrote a theory paper. They compared two word-learning ideas. Behavior analysts call it "exclusion." Cognitive psychologists call it "mutual exclusivity." The authors say both groups study the same thing.

They did not run new experiments. They read papers from both fields. They mapped the terms onto each other. Their goal was to show the two traditions fit together.

The paper finds the two labels describe one process. When a child hears a new word, they reject names they already know. That is exclusion in ABA and mutual exclusivity in cognitive science.

The authors list matching steps. Both fields show the child picks the unknown object. Both show the new name sticks after one trial. The data look the same even if the vocab differs.

Alonso‐Álvarez et al. (2018) tested the claim. They taught adults new names using exclusion cues. The results matched equivalence training. No extra relational frames were needed. Their data extend the 1993 idea into the lab.

Gomes et al. (2023) went further. They linked two full equivalence networks. Participants learned to treat one network as "same" or "opposite" to another. This shows the phenomenon scales up beyond single words.

Regaçao et al. (2025) echo the call. They ask behavior analysts to merge stimulus equivalence, RFT, and naming theory. The 1993 paper is an early voice in the same chorus.

You can borrow smart procedures from the other side. If a child masters exclusion, do not reinvent the wheel. Use cognitive tasks like fast-mapping to probe generalization. Conversely, if a psychologist says "mutual exclusivity," show them equivalence data. Shared language speeds therapy and research. Next time you teach a new tact, test exclusion first, then check for derived relations the next day.