The psychologist Penny Patterson He taught in the 1970s the American system of signs (ASL, its name in English American Sign Language) a female Gorilla named Koko. This came to learn several hundred to understand a similar number of spoken words and signs.
A day, Patterson was Koko a group of cats that he chose the most liked. The meeting between both species showed a perfect example of empathy, as for that being the size of a gorilla to interact with a tiny feline without hurting the, You must adjust their movements and caresses taking into account the fragility of the recipient, something that Koko performs to perfection.
- The Gorilla Koko receives a very special visit, It serves very carefully.
The day that one of her beloved cats died, Koko not stopped for signals which correspond to the concepts of "bad" and "sad". The female Gorilla expressed in this way that perfectly understood the tragedy of the event.
- Negative expressions of Koko after the death of one of her beloved cats.