1978: The October issue of National Geographic magazine carried an article by Francine “Penny” Patterson about Koko, a female gorilla whom Patterson had taught to use sign language. Koko knew the signs for hundreds of words (“smile”, “lollipop”, “belly button”) and was clever enough to combine them in phrases (“damn me good”, “fine animal gorilla”). She had invented some choice insults (“rotten stink”) and was not averse to the occasional lie. When she plumped herself down on a kitchen sink and dislodged it, she blamed Patterson’s assistant Kate Mann: “Kate there bad.”
A few years later, at her request, Koko was given a pet kitten, whom she named All Ball. This mischievous little animal featured in some subsequent versions of the sink story. In Brian King’s book The Lying Ape, for example, Koko reportedly pointed to All Ball and signed: “Cat did it.”
It’s possible, of course, that Koko damaged more than one sink, but I’m inclined to think that Chinese whispers were at work. Kate was blamed in the original story, but “Kate” transmogrified into “cat”, so in the end, the cat got the blame.
Source: National Geographic, October 1978