Page "Language acquisition" Paragraph 2

The capacity to acquire and use language is a key aspect that distinguishes humans from other beings.

Although it is difficult to pin down what aspects of language are uniquely human, there are a few design features that can be found in all known forms of human language, but that are missing from forms of animal communication.

For example, many animals are able to communicate with each other by signaling to the things around them, but this kind of communication lacks the arbitrariness of human vernaculars ( in that there is nothing about the sound of the word " dog " that would hint at its meaning ).

Other forms of animal communication may utilize arbitrary sounds, but are unable to combine those sounds in different ways to create completely novel messages that can then be automatically understood by another.

Hockett called this design feature of human language " productivity ".

It is crucial to the understanding of human language acquisition that we are not limited to a finite set of words, but, rather, must be able to understand and utilize a complex system that allows for an infinite number of possible messages.

So, while many forms of animal communication exist, they differ from human languages, in that they have a limited range of non-syntactically structured vocabulary tokens that lack cross cultural variation between groups.