Can Teacher Expectations Make Students Smarter? What the Pygmalion Effect Really Shows

In 1964, a psychologist named Robert Rosenthal walked into Spruce Elementary School in South San Francisco with a proposition: he’d developed a test that could predict which children were on the cusp of an intellectual “spurt”—accelerated cognitive growth compared to their peers.

The teachers administered the test. After summer break, each received a shortlist of students who were most likely to be “bloomers.”

The entire premise was a lie.

The “bloomers” had been picked at random. Rosenthal wanted to see whether teachers’ enhanced expectations would influence children’s actual progress. According to David Robson’s analysis in “The Expectation Effect,” what happened next defied everything we thought we knew about intelligence.

There was Violet—”a small, wiry tomboy with little black eyes,” the fifth of six children, known across the school for her defiance and playground fights. Despite behavioral issues, her intelligence developed tremendously over Grade 1. A second test revealed she had gained 37 IQ points in eight months.

Then there was Mario, son of a factory worker and a typist, just starting Grade 2. He was already known to be bright, though his reading aloud sometimes faltered. Eight months after the first test, his intelligence had grown by the equivalent of 69 IQ points.

Sixty-nine IQ points from nothing but a teacher’s expectations.

Not all children showed such remarkable progress. But overall, the bloomers’ intellectual gains were about twice as large as other children in their year—outstripping their classmates by 15.4 IQ points in first grade and 9.5 IQ points in second grade.

The teachers weren’t consciously paying more attention to these children. If anything, they spent less time with them. Instead, they subtly communicated their beliefs through daily interactions, which led the children themselves to take a more positive view of their own abilities.

Beliefs that allowed their young minds to flourish.

The Shocking Idea That We Can “Think Ourselves Smart”

For much of psychology’s history, intelligence was considered the ultimate nature-versus-nurture battleground. Genes were supposedly the biggest factor determining brainpower, followed by diet and home environment. The effect of expectations should have been marginal.

Rosenthal and Jacobson’s results were initially controversial. With our understanding of the expectation effect, however, the bloomers’ progress makes perfect sense.

Traits like intelligence and creativity can be influenced by our beliefs—and we often absorb assumptions from the people around us.

Too often, those expectations act like brakes that slow our progress. Once you release them, it becomes much easier to reach your potential.

The Brain Training Industry Built on Expectations

You might remember the late 2000s explosion of brain training apps. Dr. Kawashima’s Brain Training for Nintendo DS, advertised by Nicole Kidman. Lumosity, which has had more than 100 million users.

These companies claimed your brainpower was like a muscle—the more you exercised it, the smarter you became. Users often reported increased mental clarity and sharpened memories. Academic literature appeared to prove it, recording noticeable IQ differences after just weeks of regular training.

But according to Robson’s analysis, there was a massive methodological problem.

Many studies didn’t involve an “active” control—a suitable comparison that might lead participants to believe they were making useful effort. For those that did involve controls, the activity was often uninspiring (like watching an educational DVD), which didn’t evoke the same feeling of mental engagement as an interactive game.

Even more problematically, many studies recruited participants—usually university students—with ads that overtly stated they’d be taking part in a “brain training experiment.”

The expectations of improvement in each condition were completely different.

When researchers finally conducted properly controlled studies with genuine placebo conditions, the supposed IQ gains largely disappeared. What looked like brain training turning out to be largely expectation effects—people getting smarter because they believed they were training their intelligence, not because of the games themselves.

The apps weren’t worthless. But their benefits came primarily from the same mechanism as Mario’s 69-point IQ increase: believing you’re getting smarter makes you smarter.

How Stereotype Threat Steals 30% of Your Intelligence

While positive expectations can boost performance, negative stereotypes do the opposite.

In groundbreaking research by psychologists Claude Steele and Joshua Aronson, African American students at Stanford took a difficult verbal test. Half were told the test was “diagnostic of ability”—measuring their intellectual capability. The other half were told it was simply to understand problem-solving processes, with no evaluation of their intelligence.

In the “diagnostic” condition, Black students dramatically underperformed compared to White students with equivalent SAT scores. In the “nondiagnostic” condition, there was no performance difference.

The researchers validated that the “ability-diagnostic” framing cognitively activated racial stereotypes about intelligence in Black participants, creating extra pressure and worry that interfered with performance.

In another experiment, simply asking “What is your race?” on a demographic survey before a difficult test was enough to trigger stereotype threat, causing Black students to solve approximately 30% fewer problems than they would have otherwise.

The same students, the same test, different framings—completely different results.

Stereotype threat isn’t limited to race. Women underperform on math tests when reminded of the stereotype that “girls can’t do math.” Elderly people show worse memory when primed with stereotypes about aging and cognitive decline. Athletes perform differently depending on whether physical tasks are framed as tests of “natural athletic ability” (threatening for white athletes) or “sports intelligence” (threatening for Black athletes).

The mechanism is cruel: awareness of the stereotype increases motivation to disprove it, but surplus motivation interferes with performance on complex tasks. It’s like a basketball player at the free-throw line being told, “Try not to think about what a poor free-throw shooter you are.”

Growth Mindset vs. Fixed Mindset: The Belief That Changes Everything

Stanford psychologist Carol Dweck identified two fundamental orientations toward ability:

Fixed mindset: Believing abilities are immutable—you’re either good at something or not. Intelligence is a fixed trait you’re born with.

Growth mindset: Believing in capacity for improvement regardless of initial aptitude. Intelligence can be developed through effort and learning.

According to Robson’s analysis, people with growth mindsets tend to progress more quickly than those with fixed mindsets—not because they’re inherently smarter, but because their beliefs about malleability change how they respond to challenges.

Someone with a fixed mindset sees failure as evidence of limited ability and may give up. Someone with a growth mindset sees failure as information about what to work on next.

The growth mindset is now well-known in education, but it has far-reaching consequences beyond academics.

People with anxiety or depression are more likely to benefit from cognitive behavioral therapy if they have a growth mindset. Simply teaching people about the brain’s capacity to change (neuroplasticity) can itself improve physical and mental health as people realize they don’t need to become stuck in current thinking habits.

Your Brain Is More Malleable Than You Think

Through meticulous research, neuroscientists have shown that the brain’s wiring constantly changes—strengthening some connections, pruning others, sometimes adding whole new networks in response to circumstances.

At its most extreme, this process (neuroplasticity) allows people born deaf or blind to adapt to cochlear or retinal implants. While their brains are initially unable to make sense of new information, they soon rewire to build sounds and images.

But neuroplasticity occurs whenever we learn a new skill. Even personality traits once thought completely immovable—like neuroticism or introversion—can change over a lifetime.

Whatever your current situation, your brain is probably much more malleable than you think. Making changes will be easier if you hold certain attitudes about that malleability.

Breaking Free From Others’ Expectations

The Pygmalion effect—people living up or down to others’ expectations—extends far beyond elementary school.

Teacher expectations measured in early elementary school predict student outcomes decades later, even controlling for initial ability and family background. Early low expectations disproportionately affect poor children’s high school performance.

In workplaces, manager expectations affect employee performance through similar mechanisms. Attractive people earn more partly because others unconsciously expect them to be more competent. CEO voice pitch correlates with salary—deeper voices signal authority, triggering higher expectations and better treatment.

These are self-fulfilling prophecies operating at massive scale.

The implications become political when you recognize that expectation effects can increase or decrease social equality. Systematic stereotype threat in standardized testing may contribute to achievement gaps that look like ability differences but are actually expectation effects.

The good news? Robson documents cutting-edge techniques that allow us to break free from limiting expectations imposed by others:

Stereotype inoculation: Teaching students about stereotype threat itself often reduces its effects. Clinical neuropsychologists report that when they teach clients about the phenomenon, clients often start doing better on tests. Knowing that difficulty can result from social factors rather than intelligence alone reduces anxiety.

Reframing tests: Positioning tests as non-evaluative tasks (measuring how well the school is doing, not how smart students are) dramatically reduces stereotype threat effects.

Emphasizing growth mindset: Consistently communicating that abilities can improve with hard work makes stereotype threat lose potency. Research shows test scores and grades improve when teachers emphasize brain plasticity.

Self-affirmation exercises: Having students write about their core values before tests can buffer against stereotype threat by reinforcing sense of self-worth independent of stereotypes.

What This Means for Your Intelligence

The research Robson documents in “The Expectation Effect” fundamentally challenges the idea that intelligence is a fixed trait you’re born with.

Mario’s 69-point IQ increase wasn’t genetic. It wasn’t better nutrition or a suddenly improved home environment. It was a teacher’s expectation communicated through subtle daily interactions.

The 30% performance drop from stereotype threat isn’t lower inherent ability. It’s extra cognitive load from worrying about confirming stereotypes.

Brain training apps don’t make you smarter through cognitive exercise. They make you smarter (when they do) through believing you’re training your intelligence.

Your beliefs about intelligence—and others’ beliefs about your intelligence—directly shape your actual cognitive performance.

This doesn’t mean everyone has equal potential or that effort alone determines outcomes. Genetics matter. Early childhood environment matters. Educational opportunities matter.

But within those constraints, expectations create enormous variability in how much of your potential you actually access.

Releasing the Brakes

Consider the people around you—your boss, colleagues, partner, friends, teachers from your past. Do they see your potential? Or do they underestimate you?

More importantly: Do you see your own potential?

If you’ve internalized a fixed mindset—believing you’re “just not good at” certain things—you’re experiencing the opposite of the Pygmalion effect. You’re living down to your own low expectations.

The alternative isn’t toxic positivity or pretending you can do anything. It’s recognizing that your abilities are more malleable than you thought. That struggling doesn’t mean you’re incapable—it means you’re learning. That the brain you have today can rewire itself into something more capable tomorrow.

As Robson documents, people stuck in ruts trying to apply expectation effects should remind themselves of neuroplasticity. Rather than assuming you’re destined to fall into the same traps, picture your brain rewiring as you learn to see the world in new ways.

Focus on small, achievable goals that prove your capacity for personal transformation before steadily increasing ambitions. View failures as learning experiences.

You’ve had a whole lifetime to build your current worldview. Positive change takes time.

But Mario’s 69-point IQ increase proves something crucial: the limits you think you have may be nothing more than expectations waiting to be changed.

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FAQ SECTION

Q: Can expectations really increase IQ by 69 points, or was the Pygmalion study flawed?

A: The Pygmalion effect (Rosenthal & Jacobson, 1964) remains controversial and not all children showed such dramatic gains. However, Robson’s analysis in “The Expectation Effect” shows the overall pattern was robust: randomly selected “bloomers” gained twice as much as classmates (15.4 IQ points in grade 1, 9.5 in grade 2 on average). Modern research confirms teacher expectations measured in early elementary school predict outcomes decades later, even controlling for initial ability. The mechanism isn’t magic—teachers subtly communicate beliefs through daily interactions, children internalize those beliefs, and beliefs shape performance through attention, effort, and resilience.

Q: If brain training apps don’t really work, why do so many people report feeling sharper after using them?

A: According to Robson’s analysis, brain training studies often lacked proper active controls—comparison conditions that evoked equal expectation of improvement. Many recruited participants with ads explicitly mentioning “brain training experiments,” creating strong expectations. When properly controlled studies were conducted, IQ gains largely disappeared. The apps aren’t worthless—they do make people feel and perform better—but through expectation effects rather than cognitive exercise per se. You’re not training your brain’s muscles; you’re shifting beliefs about your cognitive capacity, which then affects actual performance.

Q: How does stereotype threat actually lower test scores if people are trying harder to disprove the stereotype?

A: This is the cruel paradox Robson documents. Stereotype threat increases motivation to excel (to prove the stereotype wrong), but surplus motivation interferes with performance on complex tasks requiring focus. It’s like telling someone at a free-throw line, “Don’t think about missing.” The extra pressure creates cognitive load—part of your working memory is consumed by worry and self-monitoring—leaving less capacity for the actual task. Brain scans show people under stereotype threat have heightened activation in regions associated with emotional processing, using mental resources that would otherwise support performance.

Q: Can I develop a growth mindset if I’ve had a fixed mindset my whole life?

A: Yes, according to the research Robson cites. Mindsets aren’t fixed—they’re learned beliefs that can be unlearned. Simply teaching people about neuroplasticity (the brain’s capacity to rewire itself) can shift mindsets and improve outcomes. People with anxiety or depression are more likely to benefit from cognitive behavioral therapy when they develop growth mindsets about their mental health. The key is recognizing that current struggles don’t mean permanent limitations—they mean your brain is learning and changing. Start with small, achievable goals that provide evidence of your capacity to improve, then gradually increase ambitions.

Q: If teachers’ expectations are so powerful, how can students protect themselves from low expectations?

A: Robson documents several protective strategies: (1) Awareness of the Pygmalion effect itself helps—knowing that others’ expectations can limit you makes you less likely to internalize them unconsciously; (2) Seek out mentors and environments with high expectations; (3) Develop internal locus of evaluation—judge your abilities based on your own growth rather than others’ assessments; (4) Learn about growth mindset and neuroplasticity to counter fixed-ability beliefs; (5) When facing stereotype threat, use self-affirmation exercises that reinforce self-worth independent of stereotypes. These interventions have been shown to reduce achievement gaps and improve long-term outcomes.