Ultimate attainment is similar for learners who begin by 10-12 years of age and declines continuously thereafter¶

Claim · All claims
Evidence · 1 study (2 entries) · associational r2 · q2
Currency · newest study 2018 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q2 i? Immersion learners show minimal decline in ultimate attainment until an age of first exposure of 12 years, after which decline becomes significantly steeper. → Hartshorne Joshua K. 2018 q2 i? Non-immersion learners show no decline from 4 to 9 years of exposure age, followed by a steep decline. → Hartshorne Joshua K. 2018 (2)

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

Multivariate adaptive regression splines fitted to 11,371 immersion learners with at least 30 years of experience and at most 70 years old. Slopes "B = −0.009" before age 12 versus "B = −0.06" after, per the printed coefficients.

"Immersion learners showed only a minimal decline in ultimate attainment until an age of first exposure of 12 years (B = −0.009; 0.01 SDs/year), after which the decline became significantly steeper (B = −0.06; 0.07 SDs/year)."

Hartshorne Joshua K. 2018 (2)¶

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

Same MARS analysis applied to 29,708 non-immersion learners with at least 30 years of experience. Proficiency "showed no decline" from exposure ages 4 to 9 (B = 0.01), then a steep decline (B = −0.06).

"Non-immersion learners showed similar results: From 4 years to 9 years, proficiency showed no decline (in fact it increased slightly; B = 0.01; 0.01 SDs/year), followed by a steep decline (B = −0.06; 0.07 SDs/year)."

Discussion¶

Related Claims¶

• Grammar-learning ability is preserved until about age 17.4 and then declines steadily, per the best-fitting ELSD model — 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
• Permutation tests show early-starting immersion and non-immersion learners are indistinguishable from the earliest learners, while later starters learn significantly more slowly — related
• Native and non-native learners require around 30 years to reach asymptotic performance — related
• Blocked-format span declines after age 20 but mixed-format span does not, implicating proactive interference in aging declines — related
• The age of learning-rate decline is similar for easy and difficult syntactic items — related