A two-year-old who previously said 'went' correctly now starts saying 'goed.' A parent worries this is a sign of regression. What does this change actually indicate?
AThe child is regressing due to environmental stress
BThe child has abstracted the regular past-tense rule (-ed) and is overapplying it, showing productive rule learning
CThe child is imitating incorrect speech from peers at daycare
DThis pattern indicates a developmental language disorder
Overregularization errors like 'goed' or 'mouses' are a hallmark of grammatical rule extraction. At an earlier age, children produce irregular forms correctly because they have memorized them as separate words. When they abstract the regular rule (add -ed for past tense), they overapply it to irregular verbs, temporarily replacing correct forms. This is progress, not regression — it demonstrates that children are building an abstract grammatical system rather than simply imitating.
Question 2 True / False
Nativist theories of language acquisition claim that children learn language primarily by imitating adult speech and storing frequently heard sentences.
TTrue
FFalse
Answer: False
Nativism (Chomsky's position) argues the opposite: that children are innately equipped with a Language Acquisition Device (LAD) containing Universal Grammar — abstract linguistic structures common to all human languages. The evidence against imitation-based accounts is substantial: children produce sentences they have never heard (creative use), make systematic errors (overregularization) that adults don't produce, and acquire complex syntax on the basis of impoverished, error-filled input — the 'poverty of the stimulus' argument.
Question 3 Short Answer
What does the case of Genie (a child severely deprived of language input until age 13) tell us about the critical period for language acquisition, and which aspects of language remained most impaired?
Think about your answer, then reveal below.
Model answer: Genie acquired vocabulary at a reasonable pace after rescue but never achieved normal grammatical competence despite years of intensive instruction and immersion. This supports the critical period hypothesis: lexical learning (word meanings) remains possible after puberty, but the acquisition of grammatical syntax appears to depend on exposure during a sensitive window in early childhood.
The critical period hypothesis predicts that after a sensitive window closes (around puberty), the brain's plasticity for language is reduced. Genie's case provides natural-experiment evidence: vocabulary acquisition relies on semantic memory systems that remain plastic throughout life, but the implicit learning of grammatical rules appears to depend on early-developing neural circuits. Her permanent syntactic deficits despite normal social environment and motivation suggest the critical period for grammar is real and distinct from the period for vocabulary.