15. Basic theories of language and language learning

Language may refer either to the specifically human capacity for acquiring and using complex systems of communication, or to a specific instance of such a system of complex communication. The scientific study of language in any of its senses is called linguistics.

Languages evolve and diversify over time, and the history of their evolution can be reconstructed by comparing modern languages to determine which traits their ancestral languages must have had for the later stages to have occurred.

Language learning is the process by which humans acquire the capacity to perceive, produce and use words to understand and communicate. This capacity involves the picking up of diverse capacities including syntax, phonetics, and an extensive vocabulary. This language might be vocal as with speech or manual as in sign. Language learning usually refers to first language learning, which studies infants' learning of their native language, rather than second language learning that deals with learning (in both children and adults) of additional languages.

The capacity to acquire and use language is a key aspect that distinguishes humans from other organisms. While many forms of animal communication exist, they have a limited range of nonsyntactically structured vocabulary tokens that lack cross cultural variation between groups.

A major concern in understanding language learning is how these capacities are picked up by infants from what appears to be very little input. A range of theories of language learning has been created in order to explain this apparent problem including innatism in which a child is born prepared in some manner with these capacities, as opposed to the other theories in which language is simply learned.

Over the last fifty years, several theories have been put forward to explain the process by which children learn to understand and speak a language. They can be summarised as follows:

Theory	Central Idea	Individual most often associated with theory
Behaviourist	Children imitate adults. Their correct utterances are reinforced when they get what they want or are praised.	Skinner
Innateness	A child's brain contains special language-learning mechanisms at birth.	Chomsky
Cognitive	Language is just one aspect of a child's overall intellectual development.	Piaget
Interaction	This theory emphasises the interaction between children and their care-givers.	Bruner

Behaviourism

The behaviourist psychologists developed their theories while carrying out a series of experiments on animals. They observed that rats or birds, for example, could be taught to perform various tasks by encouraging habit-forming. Researchers rewarded desirable behaviour. This was known as positive reinforcement. Undesirable behaviour was punished or simply not rewarded - negative reinforcement.