Introduction to Acquisition
- The "poverty of the stimulus"
- Different children receive drastically different input.
- Speech to children (like all speech) contains performance
errors, but these are not marked as such for the child.
- In trying to figure out what a word or a sentence means, many
different interpretations are possible.
- The lack of negative evidence
(the generative / nativist position)
- Language acquisition means in part learning the right grammar.
Each grammar is compatible with some forms and incompatible with other
forms. The data that children use in coming up with candidate grammars
are examples of grammatical forms provided by speakers of the language.
- Each of the child's hypotheses about the correct grammar is a
generatlization over the forms she has heard.
- But children may over-generalize; that is, they may get the grammar
wrong by hypothesizing one that is compatible with some ungrammatical forms.
- If children over-generalize, they apparently need
negative evidence to correct their overgeneralizations.
That is, they need to be told that certain forms are ungrammatical
as well as that certain forms are grammatical.
- But children apparently either do not receive negative
evidence or ignore it when they do.
- Given the poverty of the stimulus and the lack of negative evidence,
the only way a child could learn language is to have innate help,
constraints on the possible grammars and meanings that can be
the Language Acquisition Device
or Universal Grammar.
constraints have been proposed for each domain within language.
What might be innate?
predispositions which are specific to language, as opposed to
cognition in general
- Cognitive predispositions specific to particular
domains within language (e.g., syntax, phonology)
Why do some question strong innateness and modularity?
- The input is much richer than
it appears at first glance; caregivers may even unconsciously sequence
- Children may receive indirect negative evidence; that is, people may
fail to respond appropriately when they produce ungrammatical forms.
- There may be other types of learning mechanisms which do not require
explicit negative evidence.
- Innateness says little about the stages in language development.