OVER-GENERALISATION (also OVER REGULARISATION)
In language acquisition, wider use of a grammatical feature or concept than adult norms permit. One example is over-generalisation of inflections. Children recognise the use of-ed to mark past tense but extend it to all past forms including those that should be irregular. This often happens after the child has already mastered the correct irregular form. In a process known as U-shaped development, the child abandons accurate forms such as went and brought and adopts goed and bringed. Examples such as these provide important evidence that children do not simply parrot the words of adults but are actively engaged in a process of rule formulation and adjustment.
One account, the rule-and-memory model, represents the phenomenon in terms of a tension between a desire to apply a general rule and a memory for specific exceptions. Gradually, through exposure to multiple examples, memory comes to prevail over the rule in the case of irregular forms. An alternative, connectionist view would be that verb forms are represented by means of a set of mental connections rather than by the child forming rules. Since there are strong connections between many verb roots and past tense forms in-ed, competition determines that there is a phase in development when this is the dominant (because most statistically probable) form. Computer programs have modelled precisely this learning process.
The child may also over-generalise standard sentence patterns in its repertoire. It seems that the child learns to recognise syntactic patterns by associating them with prototypical verbs: GIVE, for example, as an exemplar of the pattern Verb + Noun Phrase + Noun Phrase (gave + Mary + a present). Other verbs are then tried out with the pattern, sometimes mistakenly. Researchers are interested in how the child seems to avoid over-generalisation in some instances, apparently recognising that these verbs are inappropriate for a given pattern.
One type of over-generalisation that has been much studied involves a double auxiliary, as in Why did you did scare me? or a double tense marking as in What did you brought? It is explained in terms of the child having imperfectly acquired the movement rules which in Chomskyan theory permit the formation of inverted questions, negatives etc.
See also: Over-extension
Further reading: Aitchison (1998: 125–34); Marcus (1996); Tomasello and Brooks (1999)
