Linguist and educator Stephen Krashen proposed the Monitor Model, his theory of second language acquisition, in Principles and practice in second language acquisition as published in 1982. According to the Monitor Model, five hypotheses account for the acquisition of a second language:
- Acquisition-learning hypothesis
- Natural order hypothesis
- Monitor hypothesis
- Input hypothesis
- Affective filter hypothesis
However, in spite of the popularity and influence of the Monitor Model, the five hypotheses are not without criticism. The following sections offer a description of the fifth and final hypothesis of the theory, the affective filter hypothesis, as well as the major criticism by other linguistics and educators surrounding the hypothesis.
Definition of the Affective Filter Hypothesis
The fifth hypothesis, the affective filter hypothesis, accounts for the influence of affective factors on second language acquisition. Affect refers to non-linguistic variables such as motivation, self-confidence, and anxiety. According to the affective filter hypothesis, affect effects acquisition, but not learning, by facilitating or preventing comprehensible input from reaching the language acquisition device. In other words, affective variables such as fear, nervousness, boredom, and resistance to change can effect the acquisition of a second language by preventing information about the second language from reaching the language areas of the mind.
Furthermore, when the affective filter blocks comprehensible input, acquisition fails or occurs to a lesser extent then when the affective filter supports the intake of comprehensible input. The affective filter, therefore, accounts for individual variation in second language acquisition. Second language instruction can and should work to minimize the effects of the affective filter.
Criticism of the Affective Filter Hypothesis
The final critique of Krashen’s Monitor Model questions the claim of the affective filter hypothesis that affective factors alone account for individual variation in second language acquisition. First, Krashen claims that children lack the affective filter that causes most adult second language learners to never completely master their second language. Such a claim fails to withstand scrutiny because children also experience differences in non-linguistic variables such as motivation, self-confidence, and anxiety that supposedly account for child-adult differences in second language learning.
Furthermore, evidence in the form of adult second language learners who acquire a second language to a native-like competence except for a single grammatical feature problematizes the claim that an affective filter prevents comprehensible input from reaching the language acquisition device. As Manmay Zafar asks, “How does the filter determine which parts of language are to be screened in/out?” In other words, the affective filter hypothesis fails to answer the most important question about affect alone accounting for individual variation in second language acquisition.
Although the Monitor Model has been influential in the field of second language acquisition, the fifth and final hypothesis, the affective filter hypothesis, has not been without criticism as evidenced by the critiques offered by other linguists and educators in the field.
Gass, Susan M. & Larry Selinker. 2008. Second language acquisition: An introductory course, 3rd edn. New York: Routledge.
Gregg, Kevin R. 1984. Krashen’s monitor and Occam’s razor. Applied Linguistics 5(2). 79-100.
Krashen, Stephen D. 1982. Principles and practice in second language acquisition. Oxford: Pergamon. http://www.sdkrashen.com/Principles_and_Practice/Principles_and_Practice.pdf.
Lightbrown, Patsy M. & Nina Spada. 2006. How languages are learned, 3rd edn. Oxford: Oxford University Press.
Zafar, Manmay. 2009. Monitoring the ‘monitor’: A critique of Krashen’s five hypotheses. Dhaka University Journal of Linguistics 2(4). 139-146.