In 1971, Penny Patterson, a graduate student at Stanford University, met Koko, a new-born gorilla in San Francisco Zoo. Penny had grown up wanting to communicate with animals and decided to teach Koko sign language in the hope of finally crossing the boundary between animals and humans.

Aired: 8/2/2016 | 0:54:51 | Expires: 9/19/2019 | Episode
Watch on the Free PBS APP
Roku
Amazon Fire TV
Apple TV
Android TV
Available on the Apple App Store
Available on Google Play