August 15, 2019
Terry Waltz

In his own words, Krashen’s Affective Filter hypothesis “claims that learners with high motivation, self-confidence, a good self-image, and a low level of anxiety are better equipped for success in second language acquisition. Low motivation, low self-esteem, and debilitating anxiety can combine to ‘raise’ the affective filter and form a ‘mental block’ that prevents Comprehensible Input from being used for acquisition. In other words, when the filter is ‘up’ it impedes language acquisition. On the other hand, positive affect is necessary, but not sufficient on its own, for acquisition to take place.”

To talk about the Affective Filter, let’s start out with its name. We’re all teachers, so of course we know the difference between affect and effect. Right? Erm… um… actually, “affect” is one of those tricky words that has extra-special meanings behind the meanings that already give a lot of us trouble. So in this case, “affect” isn’t a verb meaning “to cause something to happen to something,” but rather a noun used in psychology that means “the experience of any feeling or emotion.” So the Affective Filter is focused on feelings, and how feelings affect (see what we did there?) student language gains. From Krashen’s description, strong negative emotions act as a barrier that blocks Comprehensible Input and therefore makes acquisition impossible.

Unfortunately, this is making things just a little bit too black-and-white.

A lot of what the Affective Filter hypothesis says is common sense. If a student is experiencing some emotion to the point of distraction, it’s easy to see how the student probably won’t achieve well in the classroom. But that’s true no matter what subject is being taught—it doesn’t just apply to language (acquisition), but also to fact-based subjects that are learned, not acquired. So to hold this up as a hypothesis concerning language acquisition may be premature.

In an increasing number of cases these days, the emotions students have during class may be tied to very basic issues in their lives—things that lie very low on Maslow’s Hierarchy of Needs. A student who does not feel physically safe will be unlikely to concentrate very well on a school subject that is not important to survival in the short term. A person who has not eaten will find it difficult to focus on schoolwork even if they have the firm belief that school is the way to get ahead in life and prevent hunger in the future. These are problems that cause not only emotions but also corresponding mental reactions, such as the inability to focus consistently, which hinder learning.

But what about acquisition? Acquisition is supposed to be unconscious and automatic, right? Why should someone’s mental state influence a process that “just happens”? After all, our bodies continue to regulate our core temperature and blood sugar levels no matter what our mental state might be (even though those functions may be slightly affected by changes to emotion or mental state).

There are also strong counterexamples to this rather sweeping assertion of Krashen’s. If strong negative emotions make it impossible for Comprehensible Input to be used for acquisition, then (for example) it should be impossible for people imprisoned in horrific situations to acquire the language of their captors, and this is not the case. They do acquire language. These situations also tend to disprove the assertion that positive affect is necessary but not sufficient for acquisition, because it would be difficult to show that the prisoners had positive affect with regard to input in the jailers’ language.

But we’re teaching in a classroom, where we are not holding our students hostage. And pretty much every teacher wants to foster a positive, relaxed classroom atmosphere. Why does it even matter that there might be examples that seem to disprove this hypothesis?

The main reason is acceptance. Acceptance of students for what they are, and accepting that as a language teacher, it is not our mission nor our right to demand change from students who might be different from us.

Especially given that so many professional developments these days focus on community building and relationships and the idea that there is a certain way of doing and being and expressing oneself as a student in the classroom that is acceptable, accepting that “positive affect” is not in fact necessary to learning or acquisition is a tough thing for many teachers. Adding an almost universally-accepted hypothesis from a famous-name professor that essentially says only students who are experiencing positive emotions can acquire language reinforces the desire to make everyone visibly display and share “positive feelings” in the classroom.

And yet that student who has had their head down the entire semester still acquires language. They have not participated in the happy-snappy password exchange, they haven’t laughed at the shared class jokes, and they haven’t volunteered any answers nor taken on any class jobs. Their “participation grade” is very low indeed as a result, not that that taps into what’s really going on in their head. They may look pained, or upset, or angry, if they look up at all. And they’re probably being badgered in every single class they’re in to just do what they’re “supposed to” and not “be that way”—when they may not have any ability to change that, or when changing that may negatively impact their ability to listen and learn.

The issue here is separating the idea of “affect” (meaning the emotion a person is experiencing internally) from “affect” (the appearance a person has on the surface). We teach an enormously diverse group of learners in schools these days. They represent a huge variety of cultures and backgrounds, and our teaching staff on the whole does not reflect the same degree of diversity. When we have a student in class who comes from a culture that does not encourage eye contact with teachers (Hawaiian), a student from a culture where young people are not encouraged to speak up or question in class (some Asian cultures), or a student for whom attention does not necessarily include looking even in the direction of the speaker, let alone encouraging the speaker with facial expressions that “show interest” (many autistic people find it necessary to limit visual stimuli to listen effectively, or are often judged to have dour or inappropriate facial expressions)—it is not our job to make that student indistinguishable from the ones who are from our particular culture and react in ways we feel comfortable with.

Some of these students may be obviously identifiable as being from another group. They may wear special clothing or have names that alert us to their “different from us” status and remind us that we might need to widen our expectations to make sure those students are accepted for who they are, not for whom we might be able to make them. But there are many others who do not come with convenient or obvious labels. They may not even be able to articulate to themselves what it is that makes them “different,” but they certainly experience the effects differentness brings in a system that by and large values conformity. 

Luckily our job is to provide them with the environment from which they can acquire language—and no matter what culture or background or gender or sexual orientation or race or nationality or neurotype, every person with normal hearing and brain function acquires language in precisely the same way, through comprehended input. Focusing on making the language they hear and read language that they can understand is what will drive acquisition in these students, not making their affect positive (in the sense of their appearance or surface reactions).

That is not to say that we want to completely abandon any efforts to foster happiness, relaxation, or at least a lack of generalized anxiety in our students. Of course we want to do that, because these are the actual emotions, not the surface manifestations of internal emotions that we cannot judge (and for which students often do not have adequate descriptions or awareness of themselves). We cannot in fact change a student’s internal emotions, but we can provide an absence of conditions that we know will tend to produce negative emotions. And best of all, it’s not hard to do.

Stop worrying about the details. Respond to the content of student messages, not to the form of those messages. There are many studies that show that error correction during speech doesn’t work and in fact tends to make students anxious and hesitant to speak. If they’re worried about being dinged for a wrong verb form, they’re experiencing those negative internal emotions we’re trying to get rid of.

Be accepting. Remember that today’s classroom populations are incredibly diverse, and that you will not always be able to identify a student from a particular culture, background, experience, or neurotype just by looking. Nor will the school necessarily inform you. It’s up to the teacher to always tread lightly and respectfully and model acceptance for everyone in the class.Focus on acquisition. Stop trying to change the external affect of students. Realize that what you see on the outside may—or may not—be what’s going on in the student’s head or heart. We can input all kinds of lessons, examples, and classroom rules, but the only thing we can truly guarantee will work without fail on every human being is Comprehensible Input.

Terry Waltz

Terry Waltz can get herself into trouble in a dozen or so languages and back out of trouble again (with luck) in three. You can find more of her writings on CI at

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1 comment

  1. This is the most important thing I have read in a long time. Thank you.

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