Hakuta Kenji, Bialystok Ellen, Wiley Edward
Stanford University, CA 94305, USA.
Psychol Sci. 2003 Jan;14(1):31-8. doi: 10.1111/1467-9280.01415.
The critical-period hypothesis for second-language acquisition was tested on data from the 1990 U.S. Census using responses from 2.3 million immigrants with Spanish or Chinese language backgrounds. The analyses tested a key prediction of the hypothesis, namely, that the line regressing second-language attainment on age of immigration would be markedly different on either side of the critical-age point. Predictions tested were that there would be a difference in slope, a difference in the mean while controlling for slope, or both. The results showed large linear effects for level of education and for age of immigration, but a negligible amount of additional variance was accounted for when the parameters for difference in slope and difference in means were estimated. Thus, the pattern of decline in second-language acquisition failed to produce the discontinuity that is an essential hallmark of a critical period.
针对第二语言习得的关键期假说，研究人员利用1990年美国人口普查数据进行了测试，这些数据来自230万具有西班牙语或中文背景的移民的回答。分析检验了该假说的一个关键预测，即，在关键年龄点两侧，将第二语言习得水平回归到移民年龄的直线会有显著差异。所检验的预测包括斜率会有差异、在控制斜率的同时均值会有差异，或者两者都有差异。结果显示，教育水平和移民年龄有很大的线性影响，但在估计斜率差异和均值差异的参数时，所解释的额外方差量可以忽略不计。因此，第二语言习得的下降模式未能产生作为关键期基本标志的不连续性。
