The effects of age on second language grammar and speech production.
Level 4 - case-series / case-control
Cross-sectional observational study (graded by design analogy for non-clinical psycholinguistic research).
PubMed 23975257 · doi:10.1007/s10936-013-9261-7
What was done
The study assessed the impact of age of learning on second language (L2) grammar and speech production. The sample included 118 Mandarin-speaking immigrants to the United States and 24 native English speaker controls (n = 142 total). Grammar was evaluated via a grammaticality judgment task, and speech production was assessed by native English raters judging participants' foreign accents. Analyses tested whether age effects persisted after controlling for length of residence and years of US education.
What was found
The age of learning effect was reported as robust for both L2 grammar and speech production after controlling for length of residence and years of education in the United States, with a stronger impact on speech production than on grammar. The abstract does not report any quantitative values, effect sizes, or test statistics.
Why it matters
This study provides evidence that age effects in second language acquisition differ across linguistic domains, supporting the framework of multiple critical or sensitive periods.
Limits
The abstract provides no numerical data, effect sizes, or p-values. The cross-sectional design restricts causal inference. The immigrant sample was limited to native Mandarin speakers acquiring English, which may not generalize to other language pairs.
Cited by
- supports The critical developmental window for learning a second language without an accent closes around age 15 to 25.