Do teacher expectations unintentionally shape student success?
The Pygmalion effect in education shows how what teachers believe about students can shape their success — often without realising it.
I once sat in a parent meeting, glancing at a student’s record that had labelled them as “difficult” — and I hadn’t even taught them yet. We’ve all been there. I was reinforcing the pygmalion effect in education.
What are teacher expectancy effects?
This review paper, Questioning Pygmalion in the twenty-first century (Murdock-Perriera & Sedlacek, 2018), explores how teacher expectations—known as expectancy effects—can influence classroom interactions, grading, and student outcomes.
Drawing on 50 years of research, it unpacks how expectations form, spread between teachers, and persist over time. Expectancy effects happen when a teacher’s beliefs—based on prior data, stereotypes, or comments—shape how they treat a student.
This treatment, often subtle and unconscious, can reinforce the teacher’s original belief. For example, some students may receive more wait time for answers, better feedback, or more engaging content, simply because a teacher ‘expects’ them to do well.
These effects can occur even when teachers believe they are being fair.
Four unconscious classroom habits
Research from Harris & Rosenthal (1985) outlines four classroom mechanisms where this bias occurs:
- Climate (tone, eye contact),
- Feedback (how it’s given),
- Input (depth of curriculum), and
- Output (chances to respond).
These habits are well-researched—and usually happen without teachers realising.
Why does this matter?
These expectancy effects are a classic example of the pygmalion effect in education, where teacher assumptions become student outcomes.
In a climate of increasing data-sharing between teachers, prior assumptions about students are often passed along—sometimes before a teacher even meets the student. This can be especially harmful for students from marginalised or disadvantaged backgrounds.
What’s more, expectancies don’t fade easily. Studies suggest they can persist across year groups, despite being based on limited or even inaccurate information. Over time, these “recursive processes” can reinforce gaps in behaviour and achievement.
How can teachers reduce expectancy bias?
Teachers can begin by reflecting critically on where their beliefs about students come from. Is it data, hearsay, or a something a colleague once said? One strategy is to start with a clear overview of assessment data. Do you trust the data? What does it tell you that you don’t know? Is the data reliable? Other practical steps include:
- Using equitable questioning strategies (e.g. cold calling and random name generators).
- Balancing teacher instruction across the class, not just with ‘vocal’ or confident students.
- Tracking patterns in feedback and ensuring both high- and low-performing students receive constructive input.
CPD reflection questions for teachers:
- How are teachers forming beliefs about students before meeting them?
- What kind of data is being passed between staff during transitions?
- Do teachers expect certain behaviours from some students based on past reports?
- How evenly is teacher attention distributed in lessons?
- Are high expectations explicitly communicated to all students?
- How often do teachers reflect on their own bias in grading or questioning?
- What training could evolve as part of in-house CPD?
- Are seating plans and grouping strategies informed by past data or present observation?
- What role do SEND or EAL labels play in shaping expectations?
- How can school leaders open dialogue around unconscious bias safely and productively?
The research concludes:
Expectancy effects, when viewed as examples of these recursive processes, represent a powerful yet understudied mechanism for influencing educational outcomes.
In practical terms, what teachers believe about students can quietly shape what happens in the classroom. It’s a reminder that the way teachers think is just as powerful as what they do.