Clever Hans (German: der Kluge Hans; c. 1895 – c. 1916) was a horse that was claimed to have performed arithmetic and other intellectual tasks. After a formal investigation in 1907, psychologist Oskar Pfungst demonstrated that the horse was not actually performing these mental tasks, but was watching the reactions of his trainer. He discovered this artifact in the research methodology, wherein the horse was responding directly to involuntary cues in the body language of the human trainer, who was entirely unaware that he was providing such cues.
Logan (Boston) too. I watched an abandoned shopping bag get sniffed down before they took it away.
It’s amazing the difference between how bomb dogs move and sniff compared to drug dogs (which are 99% bullshit being triggered by handlers I suspect).
https://en.wikipedia.org/wiki/Clever_Hans