Clyde the horse, Clever Hans, and the cueing myth
The Clever Hans story is told so often that most people who repeat it have never read what the original investigator actually concluded.
In the early 1900s, a horse named Clever Hans appeared to perform arithmetic, spell words, and answer questions by tapping his hoof. The psychologist Oskar Pfungst eventually showed that Hans was not doing math — he was responding to tiny, unconscious cues from his questioner. When the questioner did not know the answer, Hans did not either.
Ever since, "Clever Hans" has been the go-to analogy whenever someone wants to dismiss assisted communication. The implication: the nonspeaker is the horse, the facilitator is the questioner, and the spelled message is the hoof tap.
What the analogy gets wrong
Hans was tapping his hoof. He was producing one-bit responses — yes/no, stop/continue. Any communicator producing novel multi-sentence prose, with idiosyncratic vocabulary, unfamiliar to the partner, in real time, is doing something Hans demonstrably could not do. There is no Clever Hans mechanism that could produce a paragraph of original poetry, a typed legal complaint, or a written argument the partner disagrees with — and we have many documented examples of all three.
The Clever Hans effect is real, narrow, and well-studied. It explains binary responses that can be derived from contextual cues. It does not, and cannot, explain open-ended language production.
What about "Clyde the horse"?
Some recent online critics have repackaged the Clever Hans story as "Clyde the horse," usually in mocking videos that compare a spelling session to a horse-trick routine. The substance of the argument is identical to the Clever Hans claim, with the same flaw: it relies on the assumption that the spelled output is a binary signal a partner could cue.
If you watch a session and the communicator types something the partner does not know, did not expect, or actively disagrees with, the Clyde framing collapses on its own terms.
The honest test
We have written about message-passing studies elsewhere — what they do well, where they fail, and what a fair design would look like. The Clever Hans analogy is not a substitute for that work. It is a rhetorical move, and a tired one.
Cueing is worth taking seriously as a hypothesis. It is not worth taking seriously as a verdict.