Wednesday, August 24, 2011

What you expect is what you get: The "Pygmalion Effect"

"Whether you think you can or whether you think you can't, you're right."
-Henry Ford

A couple of Fridays ago I posted a video about teacher who took her third grade class through an activity designed to help them learn about prejudice. When the students were told by their teacher that people with a certain eye color were smarter and better all around, they came to believe it and act in accordance. In the comments to this post, a reader noted that this video reminded him of the famous study by Rosenthal and Jacobson (1966) testing something they'd termed the “Pygmalion effect,” and so I thought I'd share that study with you today.

The Pygmalion effect? If you are not a fan of Eliza Doolittle and My Fair Lady, you might think this effect sounds like a medical condition that occurs after too much sun exposure (or is that just me?), but it’s not. What we’re talking about here is a simple case of self self-fulfilling prophecies (which Juli first wrote about here). Rosenthal and Jacobson were interested in the role of teacher expectancies in learning. What exactly does this mean? Imagine that a third grade teacher starts in the fall with a new class of students, a few of which had older sibling who passed through her class in previous years. She knows that those siblings were star students, and expects the younger siblings will also perform well. She might also talk with some of the second grade teachers who had had some of her students the previous year, and get all kinds of insider information about which students were top performers, and which straggled behind. Now let’s fast forward to the end of the year. Not surprisingly, the students whom the teacher had expected to do well met her expectations, and the stragglers continued to straggle behind. Did those star students perform well because they were smarter than the rest, as indicated by their siblings’ success and the reports of their second grade teachers? Or could it have been a much more sinister story - that they did so well simply because their teachers expected them to do well? This is exactly what Rosenthal and Jacobson wanted to find out.

The experiment:
Across six grades (1st through 6th) the researchers told teachers that a subset of their students was about to “bloom” based on their scores on a previous test, and gave them the names of these students. That is, during the next school year this group of students could be expected to make huge gains in intellectual growth. The twist? Like any good researchers would do, Rosenthal and Jacobson had randomly assigned students to this “bloom” condition, which meant that these students were no different than any of the other students in their class, with one important exception—their teachers expected them to get much smarter during that school year.

What did they find at the end of the year? Had the bloomers blossomed? Indeed, after retesting students’ IQs, they found that those in the “ready to bloom” experimental conditions gained more IQ points on average, relative to those in the control conditions. The researchers found that most of these gains happened to students in the earlier grades (first and second). In the figure shown below, you can see that in those earlier grades, students in the experimental group were making much larger gains in IQ than those in the control groups.

Some caveats: This study is famous, a classic in psychology. But as with all research, there are limitations. For one thing, they only found the effect with the younger grades. What does that mean? The researchers suggest it might be due to the fact that teachers have less preexisting knowledge about students who are younger, so they are more susceptible to the suggestion that some of them are about to bloom. It may also be that the students themselves are more susceptible to their teachers’ influence, being less certain of their own intellectual capacity. At any rate, an interesting finding. Another limitation is that the group sizes weren’t even. The researchers only selected a small percentage of students to be in the “about to bloom” group. This decision makes practical sense – what teacher is going to believe that half of their class is on the verge of an intellectual breakthrough? But we still have to interpret the results with a bit more caution, given the small sample size in the experimental condition. This is why replication is a gold standard in psych research – if we keep getting the same finding over and over again, we can start to gain confidence in the truth behind our effects.

The bottom line: Henry Ford was right -- students whom teachers believe are about to get smarter do get smarter, and thanks to Rosenthal and Jacobson, we know that teacher expectancies play a role in this. In their study, the students whom the teachers believed were about to “bloom” were actually no different than the rest of the class, but because the teachers believed they were about to bloom, they did. The teachers likely spent more time with these students, were more encouraging of them, and pushed them harder, and in response they blossomed. This is a classic case of a self-fulfilling prophecy, and one with a happy ending. But if teachers have the power in their hands to help students succeed, what do you think happens when they don’t believe in their students, and expect that they aren’t going to be a success?

Have you had experience with this type of self-fulfilling prophecy? Do you have any other ideas how these simple expectations might have molded those students into the people their teachers had expected them to become?

Further reading:

Rosenthal R, & Jacobson L (1966). Teachers' expectancies: determinants of pupils' IQ gains. Psychological reports, 19 (1), 115-8 PMID: 5942071

Rosenthal, R. (1995). Critiquing Pygmalion: a 25-Year Perspective. Current Directions in Psychological Science, 4 (6), 171-172 DOI: 10.1111/1467-8721.ep10772607

Snow, R. (1995). Pygmalion and Intelligence? Current Directions in Psychological Science, 4 (6), 169-171 DOI: 10.1111/1467-8721.ep10772605


  1. Amie,
    You asked,

    Do you have any other ideas how these simple expectations might have molded those students into the people their teachers had expected them to become?

    There are so many ways the teachers' expectation may have influenced the "bloomer" students' IQ scores. There could be very subtle factors involved. For instance, when a teacher is working directly with a non-bloomer, they may feel more anxious, as if their task is more difficult. This could be perceived consciously (or unconsciously) by the non-bloomer and give them a negative association with the student/teacher interaction. These negative signals could come across in facial expression, tone of voice, body language, etc. On the other hand, when working with bloomers, the teacher may be more relaxed, expecting an easier task, which may put the child at ease and more comfortable learning based on the positive tone of voice, body language, etc. of their teacher.

    I believe that attempting to quantify the specific factors of expectation which have a causal relationship to increases in student IQs would be extremely difficult. However, not knowing why expectation has such an impact is hardly necessary. More importantly, knowing that expectation has such an effect is enough to educate educators. High expectations = higher achievement. That's enough.

    Thank you so much for getting more in depth on this topic. As someone who works with kids daily, I'm doing my best to try to avoid any inequity in my expectations.


  2. Actually teacher expectation can sometimes do more harm than good. We are not gonna talk about favoritism or anything of that sort but pressure and keeping a clear mind state rather than striving to impress all the time.

    This kind of expectation is more often than not, not welcome by many. Not just from the teacher but the parents as well. Yes, for those who have strong will and in anyway talented or smarter than the others will excel but for those who don't will falter.