Language is difficult to define. Indeed, most books on language actually avoid giving a definition. In trying to tackle this tricky topic, Hockett (1960) set out a list of 16 design features of human language. He focused on the physical features of language rather than cognition. While this is not a perfect attempt, it is a useful frame to start our exploration.
- Vocal-auditory channel: Communication happens by vocalization by the sender and audition by the receiver.
- Transmission and directional reception: The signal travels in all directions but can be localized by the receiver.
- Rapid fading: Once produced, the signal disappears.
- Interchangeability: An individual can be both the transmitter and the receiver.
- Complete feedback: Producers of the signal have access to everything about their productions.
- Specialization: Weather whispered or shouted; the signal is the same.
- Semanticity: The signal contains meaning that related to the external world.
- Arbitrariness: The symbols are abstract and do not resemble the things they represent.
- Discreteness: The words are made up of discrete units.
- Displacement: The system can be used to reference things across time and space.
- Openness: The system can expand to invent new messages.
- Tradition: The system can be passed from one generation to the another.
- Duality of patterning: From phonemes, to morphemes, to words and sentences, the combination of meaningless units creates meaning.
- Prevarication: Humans use language to lie and deceive.
- Reflectiveness: Language can be used to discuss language.
- Learnability: Anyone who speaks a language can learn another
Now consider these design features in terms of animal communication. Do animals lack all of these features? Language is obviously about meaning and we may even add other features to human language such as creativity. But some animals have also shown the ability to lie as well as control their communication methods. Recently, Chomsky and his colleagues have argued for the syntactic creativity of language as its defining feature. The way in which we can use finite symbols to create infinite variations through iteration and recursion has been stated as unique t human languages. Kako (1999) and Pinker (2002) have listed five properties of our syntactic system:
- Language has the ability to use a discrete combinatorial system to create new meaning. In other words, when we use words, they remain distinct and do not blend together.
- Sentences need to be in a correct sequence (well-ordered) based on the syntactic category of words (e.g., nouns and verbs)
- Sentences are built around action words (verbs).
- There is a distinction between words that relate to meaning (semantics) and words that assist in syntactic structuring (function words).
- Sentences can be recursive. We can create phrases that contain other phrases that relate to the containing phrase.
Animal communication doesn’t appear to have these features. In addition, we communicate about things that are separated in time and space (unlike animals). Monkeys, for example, make signals about immediate threat such as snakes and leopards. They don’t discuss the snake they saw last summer. Animals cannot discuss their own communication system using their communication system. Therefore, while animals possess a rich communication system that they use to convey messages between members of their group, they do not bear much similarity with human language. Our (perhaps) limitless ability to employ language to discuss anything and everything is mind boggling. In essence, all non-human communication systems are different from human language.