Critical and sensitive periods
결정적 시기와 민감기
Also known as: sensitive period
The idea that there is a window especially favourable for acquiring language, now usually described as a gradual sensitive period rather than a hard cutoff.
The original claim was a sharp drop in language acquisition around puberty (Lenneberg, 1967), often paired with findings that immigrants' grammar ability varied by age of arrival (Johnson and Newport, 1989).
A large online study of hundreds of thousands of people later reported that grammar learning ability holds into the late teens and then declines gradually (Hartshorne et al., 2018). The door does not slam shut.
For parents the conclusion is modest: starting early helps with sound and listening, but starting later is not too late. Consistent exposure and use matter more than age.
- Current viewA gradual slope, not a cliff.
- PracticeConsistency beats an early start.