Apparently the horse 'knew' the right answer by inferring from the questioner's behaviour: "Pfungst (the debunker) then examined the behaviour of the questioner

Apparently the horse 'knew' the right answer by inferring from the questioner's behaviour: "Pfungst (the debunker) then examined the behaviour of the questioner in detail, and showed that as the horse's taps approached the right answer, the questioner's posture and facial expression changed in ways that were consistent with an increase in tension, which was released when the horse made the final, correct tap. This provided a cue that the horse could use to tell it to stop tapping." [1] However, there are gene regulatory networks that can actually count up to 3, with the mechanism of counting up to 2 being curiously different than the one for counting up to 3. [2] "Every intelligence test is also a test of the questioner" [3]: we don't regard a simple liver cell as intelligent, yet it performs a complex task in a large problem space. [1] https://en.wikipedia.org/wiki/Clever_Hans#:~:text=Pfungst%20then%20examined,to%20stop%20tapping https://en.wikipedia.org/wiki/Clever_Hans#:~:text=Pfungst%20.... [2] 2013, Malte Lehmann, "Genetic Regulatory Networks that count to 3", https://pubmed.ncbi.nlm.nih.gov/23567648 https://pubmed.ncbi.nlm.nih.gov/23567648 [3] Michael Levin, "Bioelectric Networks: Taming the Collective Intelligence of Cells for Regenerative Medicine", https://www.youtube.com/watch?v=41b254BcMJM https://www.youtube.com/watch?v=41b254BcMJM