Great Apes Can Learn Sign Language

While animals don’t naturally use human language, some great apes have learned to communicate using sign language in research settings. The most famous example is undoubtedly Koko the gorilla, who reportedly learned more than 1,000 signs from American Sign Language and understood thousands of spoken English words. Chimpanzees, bonobos, and orangutans have also demonstrated an ability to learn signs or use keyboards featuring symbols to communicate with their human caretakers.

Scientists continue to debate exactly what these abilities reveal about language, however, since human grammar is far more complex than the communication systems apes have mastered. Even so, this research proves our closest-living relatives can learn to communicate with surprising flexibility.