Hugh Loftings character, Dr. Doolittle, could talk to animals and they talked back. Many people fantasize about having such a skill. Imagine being able to talk to your household pets and getting a response back. Could it ever be possible? Language acquisition studies among primates such as gorillas, chimpanzees, and bonobo chimpanzees suggest that the answer is yes, and no.
There has been some success with teaching gorillas to communicate with humans. The most famous example of this is Koko, a gorilla who learned American Sign Language (ASL). Koko was born in 1971 and became part of a language acquisition study when she was one year old. Her trainers claim that she knows over 1000 ASL signs and can understand about 2000 words of spoken English. She can make statements averaging three to six words. Koko is considered one of the most successful attempts at teaching sign language to primates.
Teaching sign language to chimpanzees has been less successful. Nim Chimpsky was the most famous example of a chimp who could sign. Like Koko, he was raised like a human infant and taught American Sign Language. He was the first chimp to be taught ASL. He learned about 125 signs over four years, but he seldom signed spontaneously. Most of his communications were in response to his trainers signs. It was eventually determined that he would never be able to master the human language but by observing him, scientists were able to gain a better understanding of how chimpanzees communicate with each other.
Bonobo chimpanzees have proven to be quite good at acquiring some form of language. A case in point is Kanzi. He was born in 1980 and stayed with his adoptive mother while she was being taught a language system made up of picture symbols on a keyboard. His mother was not very successful, having started to learn as an adult. When Kanzi was two and half years old, the researchers discovered that Kanzi not only knew the picture symbols, but he understood the spoken words they represented. Just like a human infant, Kanzi had learned the system by being exposed to it, rather than having it taught to him. Eventually he could produce 200 words using the picture symbols and understood about 500 spoken words. His understanding of spoken human language is considered to be the same as a two and a half year old human childs.
None of these primates can communicate fluently with humans. However, we have learned from Koko, Nim Chimpsky and Kanzi that while primates may not be capable of mastering human language, they are capable of using a communication system. Perhaps it is up to us to learn their communication systems before we, like Dr. Doolittle, can talk to the animals.