Francine "Penny" Patterson is an American animal psychologist. She is best known for teaching a modified form of American Sign Language, which she calls "Gorilla Sign Language", or GSL, to a gorilla named Koko beginning in 1972.
Francine "Penny" Patterson is an American animal psychologist. She is best known for teaching a modified form of American Sign Language, which she calls "Gorilla Sign Language", or GSL, to a gorilla named Koko beginning in 1972.