Final answer:
Beatrix and Allen Gardner taught the chimpanzee Washoe to communicate using sign language. This effort demonstrated that great apes could learn a form of protolanguage including a symbolic system, suggesting an innate capacity to understand such systems.
Step-by-step explanation:
The chimpanzee Washoe was taught to communicate by Beatrix and Allen Gardner using sign language. Unlike human language, the communication systems of other primates, such as chimpanzees, tend to be more restricted in complexity and diversity. The Gardners' efforts with Washoe, however, showcased that great apes possess the basic capacity for learning and using a form of protolanguage. Although the communicative abilities of apes learned through human intervention raise questions about the biological and cognitive underpinnings of language, these studies suggest that apes may have an innate capacity for understanding symbolic systems to a certain extent.
Studies conducted on other great apes like Koko the gorilla, who was taught by Dr. Francine Patterson, reinforce the idea that nonhuman primates can learn to use sign language. This ability to learn and use a symbolic system differentiates human language from other animal communication methods, which are typically not as open-ended or versatile. The research into primate language abilities provides valuable insights into the evolutionary and developmental aspects of communicative functions among primates, demonstrating that while they do not naturally develop language, they can acquire a basic form of human language interaction when taught.