After 44 years, Project Koko is the world’s longest ape-language study and, according to Penny, the most successful, with Koko mastering hundreds of signs. After a lifetime together, Penny and Koko share a bond similar to that of a mother and daughter.
Early on, their relationship survived the San Francisco Zoo's attempts to reclaim Koko, ejection from the university where Penny gained her PhD, and skepticism from parts of the scientific community, which began to doubt the validity of Penny’s claims. Like any mother, Penny fought for Koko at every turn.
This is the unique story of the life-long relationship between scientist Penny Patterson and Koko the gorilla.