The question of whether animals can learn and use language has long captivated human curiosity. People often wonder about the cognitive abilities of other species and how their communication systems compare to our own. Exploring this topic offers insights into animal intelligence and the distinct characteristics of human cognition. It prompts a deeper understanding of what truly defines language and whether its complexities are exclusively a human domain.
Understanding “Language”
Language is differentiated from simple communication or mimicry by several characteristics. Semanticity refers to the use of symbols that carry specific meanings, enabling reference to objects or ideas. Arbitrariness means there is no inherent logical connection between a symbol and the concept it represents; for instance, the sound “cat” does not physically resemble the animal.
Language also possesses displacement, allowing communication about events or objects not immediately present, including those in the past, future, or abstract concepts. Productivity, or creativity, highlights the ability to generate and understand an infinite number of novel messages from a finite set of elements. Human language exhibits duality of patterning, where meaningless units (like sounds) combine to form meaningful units (words), which then combine into larger structures. These criteria help scientists evaluate whether an animal’s communication system qualifies as language.
Key Animal Language Research
Early research into animal language involved chimpanzees, such as Project Washoe, initiated in 1966. Researchers taught Washoe American Sign Language (ASL) by immersing her in an environment where only ASL was used. Washoe acquired over 130 signs and combined them into spontaneous, contextually appropriate phrases like “MORE TICKLE” or “COME OPEN.” Her learning mirrored aspects of human child language acquisition.
Other chimpanzees also participated in language studies. Sarah used plastic tokens as words in an artificial language system, demonstrating an ability to understand and use symbols. Lana communicated using a computer-based system with “lexigrams,” enabling her to formulate requests like “please machine give water.” While these chimpanzees showed impressive symbol use, questions remained about the spontaneity and grammatical complexity of their productions.
The bonobo Kanzi, born in 1980, showed remarkable linguistic aptitude through observational learning. He learned to use lexigrams and demonstrated comprehension of spoken English, understanding about 3,000 words. Kanzi’s ability to respond correctly to novel spoken commands suggested comprehension comparable to a two-year-old human. He also exhibited rudimentary word order in his lexigram use, showing some understanding of grammatical rules in English.
Gorilla Koko, born in 1971, was taught a modified version of American Sign Language, reportedly acquiring over 1,000 signs and understanding approximately 2,000 spoken English words. Koko’s trainer claimed she could invent new signs, such as combining “finger” and “bracelet” to communicate “ring.” However, scientific consensus indicates Koko did not demonstrate the syntax or grammar required for true language, and some claims relied heavily on human interpretation.
Beyond primates, research explored language-like abilities in other species. Alex, an African Grey parrot, developed a vocabulary of over 100 words and appeared to understand the concepts behind them, identifying shapes, colors, and materials. Alex could answer questions about objects, distinguish between “same” and “different,” and grasped the concept of zero, demonstrating cognitive abilities previously thought to require a primate brain. Studies on bottlenose dolphins identified “non-signature whistles” that convey specific meanings shared by multiple dolphins, potentially forming the basis for a language-like communication system.
Distinctions from Human Language
Animal communication systems do not fully meet all the criteria defining human language. A primary distinction lies in the complexity of syntax, the rules governing how words combine to form sentences. While some animals, like Kanzi, show evidence of understanding word order, their productions lack the intricate grammatical structures and recursive nature seen in human language, where sentences can contain other sentences. This limited ability to combine small units into larger, novel expressions distinguishes animal communication.
Human language exhibits remarkable productivity, allowing for the creation of an infinite number of new sentences and ideas. Animal communication systems, by contrast, are more closed or limited in the range of messages they can generate. While animals communicate about immediate needs or present stimuli, human language features displacement, enabling discussion of abstract concepts, hypothetical scenarios, or events in the past and future. Animal communication is largely context-driven, reacting to immediate environmental cues.
The motivation behind communication also differs. Human language use is spontaneous and driven by an intrinsic desire to share information or engage socially. Animal communication, especially in experimental settings, appears reward-driven or focused on obtaining specific outcomes like food. Human language is culturally transmitted, learned and passed down through generations within a community, rather than being solely biological. While some animals learn communicative behaviors, the depth and flexibility of cultural transmission in language are unique to humans.
Underlying biological and cognitive structures also contribute to these differences. Humans possess unique vocal tracts enabling a wide range of speech sounds, which most animals lack. The ability to use arbitrary symbols and combine them creatively for diverse purposes, even when not immediately relevant to survival, remains a hallmark of human linguistic capacity.