What Is the Affective Filter, and Why Is it Important in the Classroom?

by Valentina Gonzalez

What Is the Affective Filter?

The term “affective filter” originates from Stephen Krashen, an expert in the field of linguistics, who described it as a number of affective variables that contribute to second language acquisition. Merriam-Webster’s Dictionary defines affective as “referring to, arising from, or influencing feelings or emotions.”

Krashen (1986) cites motivation, self-confidence, and anxiety in the Affective Filter Hypothesis as three categories of variables that play a role in second language acquisition. In essence, when feelings or emotions such as anxiety, fear, or embarrassment are elevated, it becomes difficult for language acquisition to occur. The affective filter has commonly been described as an imaginary wall that rises in the mind and prevents input, thus blocking cognition. In opposition, when the affective filter is lowered, the feeling of safety is high, and language acquisition occurs. In fact, even current research in neuroscience seems to support Krashen’s theory that stress affects thinking and learning. 

Why Is the Affective Filter Important in the Classroom?

It is not enough to simply teach. It is not enough to deliver instruction even if it’s made comprehensible to students. If students’ affective filters are elevated, language acquisition will be impeded. Creating classroom environments that act intentionally to lower the affective filter will increase language development. 

The lower the filter, the more input is allowed to pass through. Students who are highly motivated, feel confident, and feel safe are more open to input. 

Let’s picture two classrooms:  

  • In the first classroom, students walk in and sit in isolated rows. The teacher reads from a scripted lesson before assigning a worksheet for students to complete independently. Talk is discouraged, and students are quickly reprimanded for stepping outside of the planned lesson. It is clear to the students that their role is to comply with the teacher’s rules for the classroom. 
  • In the second classroom, students have a voice in instruction. They are part of their learning journey. This creates motivation to learn. They gather in groups to share ideas, and they are encouraged to take risks, which helps build their self-confidence. The classroom talk is balanced with some teacher talk and some student talk. Students feel comfortable sharing their ideas and opinions.

When you imagined these two classrooms, in which one did you feel that students had more room to bloom freely within the context of the content? The teacher in the second classroom had a way of lowering the affective filter for students. But how? 

How Do We Lower the Affective Filter in the Classroom?

The answer is similar to how you might make visitors feel welcome at your home. Typically, if you want company to stay, you create a space that is inviting, comfortable, friendly, and interesting. You cater to their needs, offer them food, and pay attention to them. (And, I don’t know about you, but if I don’t want company to stay for long, I simply don’t do these things!)

We can lower the affective filters of our students in our classroom in similar ways to how we make visitors feel welcome in our homes. Let’s examine how this might look through the three categories that Krashen proposed: motivation, self-confidence, and anxiety.


Some might think motivation is solely up to individual students. But while educators don’t have complete control over student motivation, they can still influence it. Choice, voice, and relevance are three great motivators we can leverage in the classroom. Providing students with opportunities to select topics to study helps them feel motivated to do the work. Allowing students choice in what they write about or how they show understanding also builds motivation. Creating time and space for students to share their voice in learning stimulates a drive in learners. When students feel they have some say or some control over their learning journeys, they become more invested. Finally, providing learners with engaging experiences that tap into their passions increases motivation. When we keep instruction relevant to students’ lives, what they are learning becomes compelling to them. 


Learners who feel a sense of belonging, value, and respect for their individuality are more likely to have lower affective filters. Creating classrooms that warmly welcome all students builds self-confidence. On the other hand, when students feel isolated or that they must “fit in,” their self-confidence erodes. To build self-confidence, educators can work on correctly pronouncing students’ names, ensure that walls and books are representative of the student population, and get to know students for who they are beyond the classroom. 


A safe classroom is one in which students are not afraid to make errors. Classrooms that embrace errors as part of the learning process are more likely to decrease students’ affective filters. Fostering a growth mindset and modeling this mindset with students can help them understand that mistakes are a part of growth in the process of learning. The way we talk with students and our body language can also affect their anxiety. Even students who are not yet speaking in English can understand body language and feel the energy in a classroom. Smiling sends a positive, warm message; sitting next to a student to confer with them rather than sitting in front of them is less confrontational; arms at the side rather than crossed is less aggressive. Another way to lower the affective filter is by making sure that we provide comprehensible input. Students become more focused and relaxed the more they can understand the language being used during instruction.

On the other hand, there are specific moves we make that can be counterproductive and raise the affective filter. The factors below can raise the affective filter and impede language acquisition: 

  • Error correction
  • Forcing output too early
  • Isolation
  • Embarrassment
  • Lack of comprehensible input

We may not even know that we are doing these things or that they are causing the imaginary wall to come up. But becoming aware of the affective filter, what raises it, and how to lower it can help language acquisition flourish. 


Krashen, S. D. (1986). Principles and practice in second language acquisition. Oxford: Pergamon Press. http://www.sdkrashen.com/content/books/principles_and_practice.pdf

3 thoughts on “What Is the Affective Filter, and Why Is it Important in the Classroom?

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