Grammar-learning ability is preserved until about age 17.4 and then declines steadily, per the best-fitting ELSD model¶
Claim · All claims
Evidence · 1 study · associationalr2·q2
Currency · newest study 2018 · checked against its sources 2026-10-20 (automated, 1 of 1 entry) · not reviewed by a person
Subclaims¶
Reading the evidence codes
q is the design tier, i the impact, n the sample, and the kind with its r
the rigour judged within that kind: what each code means.
This claim: no standardized effect is recorded in observations/ for it yet, so no benchmark reading is possible.
q2 i? The best-fitting model of syntax acquisition involves a learning-rate change beginning at 17.4 years, fitting better than constant-rate or step-function alternatives. → Hartshorne Joshua K. 2018
Evidence¶
Hartshorne Joshua K. 2018¶
Hartshorne Joshua K., Tenenbaum Joshua B., Pinker Steven. (2018). A critical period for second language acquisition: Evidence from 2/3 million English speakers. Cognition. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6559801/
q2 · i? · associational · r2
Numerical model fitting to performance curves from 244,840 monolinguals, 44,412 immersion learners, and 257,998 non-immersion learners. The "best-fitting model (R2 = 0.89) involved a rate change beginning at 17.4 years", beating constant-rate (R2 = 0.66) and step-function (R2 = 0.70) alternatives.
"The best-fitting model (R2 = 0.89) involved a rate change beginning at 17.4 years (Fig. 4E). The fit was significantly better than the best fit for alternative models in which learning rate did not change (R2 = 0.66) or changed according to a step function with no further decline in the learning rate after the initial drop (R2 = 0.70)."
Discussion¶
Related Claims¶
- Ultimate attainment is similar for learners who begin by 10-12 years of age and declines continuously thereafter — related
- The age of learning-rate decline is similar for easy and difficult syntactic items — a narrower finding that bears on this claim
- Comprehensible input alone is insufficient for acquisition of high levels of grammatical proficiency — related
- Older-arriving ESL learners transfer L1 knowledge efficiently, but learning slows once they outgrow their L1 — related
- Later age of entry to a signing school for the Deaf is associated with lower ASL syntactic judgment and analogical reasoning scores, with a marked decline for entry after age 12 — related
- Ultimate attainment and optimal-period length do not reliably differ across major native-language groups, with slightly more evidence for differences in learning curves — related
Page metadata
| Field | Value |
|---|---|
type |
claim |
id |
grammar-learning-rate-declines-after-17-4-years |
title |
Grammar-learning ability is preserved until about age 17.4 and then declines steadily, per the best-fitting ELSD model |
description |
Grammar-learning ability is preserved until about age 17.4 and then declines steadily, per the best-fitting ELSD model |
status |
review |
evidence_strength |
moderate |
newest_evidence |
2018 |
source_checked |
2026-10-20 |
generated |
by process:wiki-ingest on 2026-10-17 |
trust |
unverified — no one has confirmed this page's content |
sources |
1 — hartshorne-joshua-k-2018 |
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