Behavior analysis, relational frame theory, and the challenge of human language and cognition: A reply to the commentaries on relational frame theory: A post-skinnerian account of human language and cognition.

Najdowski et al. (2003) wrote a reply to critics of Relational Frame Theory.

They said the data on arbitrarily applicable relational responding are too strong to ignore.

The paper urges behavior analysts to face RFT’s challenge to Skinner’s older account of language.

The authors found that derived stimulus relations keep showing up in labs.

They argue these patterns are operant behavior, not magic.

Because the effect is reliable, they say, we must fold it into behavior analysis.

Osborne (2003) reviewed the same RFT book and said, "Relax, this is still Skinner." C et al. answer, "No, it’s a real shift."

Schoneberger (2025) ends the fight. He says Skinner’s definition and RFT’s definition serve different jobs, so both can live on the same toolbox shelf.

Barnes-Holmes et al. (2018) later pile on more data, showing two decades of derived-relations work that makes the challenge even harder to brush off.

If you run verbal behavior programs, you now have to decide where derived relations fit. Start testing for emergent relations after standard tact and echoic drills. One quick move: add a simple equivalence probe set after each mand session and note if untrained responses pop out. Those free responses are the RFT signal C et al. say you can’t ignore.