It’s time for a thought experiment!

Imagine what would happen if most people working in engineering did not have a correct understanding of the basic principles of physics. Alternatively, ponder what would happen if a majority of physicians had incorrect ideas about biology and the causes of disease.

Of course, the result would be disastrous. Engineering and medicine are areas of applied physics and biology (respectively). Understanding the science behind these applied fields is essential for people to be successful practitioners.

My latest study (Warne & Burton, 2020), unfortunately, shows that this is precisely what happens in education, which is an applied psychology field. In a survey of a convenience sample of 200 K-12 teachers, a majority held incorrect beliefs about a wide variety of facts about intelligence. This is disturbing because IQ is one of the best predictors of educational performance, and intelligence differences are one of the causes of differences in educational outcomes. A teacher who has many incorrect beliefs about intelligence is the equivalent of a physician who does not understand biology.

My student co-author and I administered a survey with 85 close-ended items on it to our sample of teachers. For most items, teachers indicated the degree to which they agreed with statements about human intelligence. Among the most widely held but incorrect ideas:

  • 84.5% of teachers endorsed Howard Gardner’s empirically unsupported theory of multiple intelligences.
  • 69.5% believed that a good teacher could equalize differences in school success.
  • 65.0% agreed with the statement that emotional intelligence is more important for success at work than IQ.
  • 64.0% believed that an intelligence test only measures how well a person performs on intelligence tests.
  • 59.5% did not think that intelligence tests are important for measuring success in life outside of school.
  • 57.5% agreed with the statement, “Even if intelligence exists, personality traits are more important for life success than intelligence.”
  • 51.0% endorsed the training hypothesis, which is the idea that anyone could, with enough training, master complex skills.
  • 49.5% disagreed with the claim that individuals with larger brains tend to be smarter.
  • 48.0% disagreed with the statement that a student who earns high grades in one school subject will generally earn higher grades in other subjects.

Some of these responses are simply mind-boggling. How could nearly half of teachers not believe that students who perform well in one school subject usually perform better in another subject? This is a finding that dates back over 100 years (Spearman, 1904) and is one of the most replicated findings in all of educational psychology. How do teachers not notice that honors students tend to do well in all their classes and struggling students tend to struggle in all their classes? Clearly, grades are correlated.

Teachers are confused about many of the most basic facts about intelligence.

Likewise, having half of teachers agree with the training hypothesis is shocking. Haven’t these teachers ever encountered a student who just simply couldn’t master complex skills, despite everyone’s best effort? Do they really believe that every child can master calculus or advanced writing–despite the overwhelming evidence to the contrary? If so, this is a disturbing level of denial or ignorance about human cognitive abilities.

Teachers also display a faith in the malleability of intelligence, believing that the following treatments could increase IQ:

  • Parents reading to a child daily: 10.9 points
  • Having an effective teacher every year in elementary school: 8.5 points
  • Well-funded schools with small class sizes: 8.2 points
  • A high quality preschool program: 7.6 points
  • Regular use of educational games in childhood: 6.7 points
  • Music lessons in childhood: 6.6 points
  • A typical preschool program (e.g., Head Start): 6.0 points
  • Growing up in a wealthy family: 5.8 points
  • Brain training games for elderly individuals: 5.3 points
  • Talking to a child in the womb regularly: 5.0 points
  • Breastfeeding in infancy: 4.4 points
  • Ensuring that a person stays in school for an extra year: 4.4 points
  • Watching educational programs on TV: 4.3 points
  • Having access to the internet in the home: 4.1 points
  • Multivitamin supplements during pregnancy: 4.0 points
  • Listening to classical music during infancy: 3.8 points
  • Being married in adulthood: 3.0 points
  • Consuming a vegetarian, low-fat diet in childhood: 2.3 points
  • Being popular with classmates as a child: 2.2 points

The point values for each intervention are the average IQ point increase that teachers expected to as a result of a person experiencing the intervention. Only the treatments marked in bold have evidence supporting any impact on permanently raising IQ. But even for these interventions, the impact of each treatment is weaker than what teachers expect.

That being said, it is heartening that the three fake treatments that we made up (italicized in the list above) were the ones that teachers thought would be least effective. Teachers seem to have an instinctive understanding of which changes to the environment will have a weaker impact on IQ.

It is also encouraging that the teachers had a slightly more realistic view of the effectiveness of interventions to permanently raise IQ than the non-teachers. On average, the non-teachers thought that the interventions would raise IQ by 2.2 points more than the teachers. So, even though the teachers are overly optimistic, the non-teachers are even more so.

Nevertheless, there is a general lack of understanding of the basics of intelligence. If this convenience sample is typical, then most teachers hold ideas that are so wrong that similarly severe misunderstandings in medicine or engineering would put people’s lives in danger. Teachers have several misunderstandings about the importance of intelligence, its impact on schooling outcomes, and the malleability of IQ. This study is one of many data points that shows the need for my upcoming book, In the Know: Debunking 35 Myths About Human Intelligence, which addresses many of these misconceptions.

This study is part of a growing body of evidence showing that educational professionals hold beliefs that are not supported by empirical evidence. For example, a prior study that we published showed that university education departments offer many courses teaching the empirically unsupported theory of multiple intelligences (Burton & Warne, 2020). Teachers’ overwhelming belief in mindset theory (with its shaky evidence) is another example. Teachers’ lack of knowledge about one of the most important traits for educational success is embarrassing for the field and potentially harmful for students.

The only remaining question is why the educational establishment is so comfortable operating with beliefs that are so disconnected from the scientific evidence about intelligence. Why is a field that supposedly values knowledge and understanding so dreadfully ignorant about human learning?

I invite readers to read the article for themselves. With over 80 items on the survey, the summary here is only a taste of the results. The survey reveals a great deal of uncertainty about information related to intelligence among both teachers and non-teachers. Additionally, the article has a testable hypothesis about the types of beliefs that non-experts have about intelligence. There is a freely available preprint version, and the supplementary tables and raw data will be useful for people who want to get more details or perform their own analyses.

Update: Jurij Fedorov has created an interactive data exploration tool that allows users to compare teachers’ and non-teachers’ on every survey item. Other demographic group comparisons are possible.

While both teachers and non-teachers believe in multiple intelligences, the teachers (in green) are much more confident in this believe than the non-teachers (in red). Source: Jurij Fedorov’s data exploration tool.


Burton, J. Z., & Warne, R. T. (2020). The neglected intelligence course: Needs and suggested solutions. Teaching of Psychology, 47(2), 130-140.

Spearman, C. (1904). “General intelligence,” objectively determined and measured. American Journal of Psychology, 15(2), 201-293.

Warne, R. T., & Burton, J. Z. (2020). Beliefs about human intelligence in a sample of teachers and nonteachers. Journal for the Education of the Gifted, 43(2), 143-166.