Professor Lee argues that children acquire language through a combination of innate grammatical capacity and environmental input. She claims this explains why children in impoverished language environments still develop grammar but with smaller vocabularies.
Which observation would best support Lee's dual-factor theory?
Children from book-rich homes knew 30% more words but used equally complex grammar as children from book-poor homes
Children worldwide learn their first words at approximately the same age
Adults learn second languages more slowly than children learn first languages
Some children begin speaking earlier than others
Correct Answer: A
Choice A is the best answer. Vocabulary varies with environment; grammar stays equal—showing both factors at work.
- Context clues: Lee proposes both innate (grammar) and environmental (vocabulary) factors.
- Evidence evaluation: Different vocabulary + same grammar = dual factors.
- Verify: Environmental input affects vocabulary; innate capacity handles grammar.
💡 Strategy: Dual-factor theories need evidence showing each factor's distinct effect.
Choice B is incorrect because universal timing could support innate-only theories. Choice C is incorrect because child vs adult comparison doesn't address the dual-factor claim. Choice D is incorrect because individual variation doesn't distinguish innate from environmental.