What’s Behind Rising IQ Scores?

Key Takeaways

• People’s IQ scores have been rising over time due to various factors.
• Some improvements in IQ scores could be from better education and fewer siblings.
• Better nutrition during pregnancy might also boost IQ scores.

Standing for intelligence quotient, an IQ test is a tool that measures one’s ability to reason and use logic to solve problems and answer questions. Basically, it’s a test that measures intelligence.

People’s Average IQ Increases Over Time

The Flynn Effect is a phenomenon discovered by intelligence researcher James Flynn that determined the average IQ of humans steadily increases over time, thus showing promise that our society’s intelligence only grows as civilizations develop.

This article will unpack the Flynn Effect, its background, and why it is important to our current society. It will also cover the reverse Flynn Effect, its potential causes, and why we should be wary of placing too much weight on IQ tests in general.

What Are IQ Tests Used For?

IQ tests are used as a measure of intelligence. They also can be used to diagnose learning disabilities. If someone is diagnosed with a disability, they may be eligible for special accommodations and services, including support provided by the Americans with Disabilities Act and Social Security Disability Insurance.

In the past, someone’s IQ test results may have determined whether or not they’ll receive capital punishment for committing a crime in the U.S. For example, the outcome of the 2002 Atkins v. Virginia case led to the banning of capital punishment for intellectually disabled individuals, thereby no longer making IQ test results the difference between life and death.

IQ Tests Have Proven to Be Problematic

The 1979 Larry P. v. Riles’ court case explored racial bias among intelligence tests. This court case found that the use of IQ tests was used as a tool of discrimination to place African-Americans in special education classrooms. As a result, the use of IQ tests to place African-American children in special education classes was banned.

Furthermore, IQ tests can overlook other forms of intelligence, including socio-emotional skills and interpersonal relationship skills. This leads to a one-dimensional understanding of intelligence, which undermines the full intellectual capacity of human beings. There is a long history of doubt surrounding the validity of IQ testing, often for reasons of bias.

What Exactly Did James Flynn Discover?

In 1984, James Flynn discovered a 13.8-point IQ score increase between 1932 and 1978. In other words, people’s IQs increased by about 3 points per decade. Basically, the Flynn Effect found that people’s IQ scores rise over time.

People’s IQs increased by about 3 points per decade.

Additionally, this phenomenon suggests that people are more likely to score higher on an outdated version of an IQ test than on a current version.  

What Causes the Flynn Effect?

Let’s take a look at some of the factors that contribute to the Flynn Effect:

• Growing up with fewer siblings: Having fewer siblings was associated with an increase in IQ scores. This could be attributed to the increased support and attention offered by parents who don’t have to split their attention amongst a large number of children.
• Better nutrition in people who are pregnant: Enhanced nutrition during the prenatal and early postnatal stages are also considered a potential factor in the Flynn effect. Additionally, the increased public awareness regarding alcohol and tobacco use during pregnancy led to a decrease in usage amongst pregnant women. 
• An evolving world: The evolving nature of our world has led to increased environmental complexity. In turn, generations have become more adept at reasoning and problem-solving.
• Education systems have improved: As test-taking has become more normalized in our culture, it is possible we have collectively increased our test-taking confidence. 

How Does the Flynn Effect Impact Society?

Consider how influential IQ tests have been in our society. It is a general marker of whether or not someone is deemed intelligent. It has been used as an instrument contributing to discrimination, like in the case of Larry P. v. Riles.

It can determine whether or not someone receives essential disability aid from the United States government. Beyond that, it can be what influences the outcome of a capital punishment case. Therefore, the accuracy of IQ tests is essential to maintaining a fair and just society. Inaccuracy of these tests can lead to further oppression. 

The Flynn Effect has also led many to feel positive that intelligence is only evolving across decades. This can inform the public opinion of how humans are growing and adapting to our rapidly changing society. 

A Newer Phenomenon—The Reverse Flynn Effect

While it’s difficult to be certain whether intelligence is decreasing or increasing, a decline in intelligence is known as the reverse Flynn Effect. Recent research is indicating an overall decline in intelligence, however, that may not mean our society is actually becoming less intelligent. Instead, it may be more indicative of a changing society.

Younger Generations Have Lower Test-Taking Confidence

Research suggests the decline can be attributed to shifts in the quality of education received, decreased nutrition, and changes in test-taking behavior. When it comes to test-taking behavior, it is hypothesized that younger generations are experiencing decreased test-taking confidence or are not responding particularly well to the format of IQ tests.

Anti-Immigration Rhetoric and the Reverse Flynn Effect

Recent research has suggested the reverse Flynn Effect is due to immigration, noting that the migration of those from countries with lower IQs into a country with a higher IQ can result in an overall lower IQ. Not only has this hypothesis been debunked, but it can also lead to anti-immigration rhetoric.

It is critical to realize that IQ tests can be used discriminately and the reverse Flynn Effect does not necessarily indicate decreased intelligence. Let us not forget how the Larry P. v. Riles case illustrated how problematic IQ tests can be for disenfranchised populations.

Can We Rely on IQ Tests?

Human intelligence is far more complicated than a standardized test can capture. Our environment is constantly changing and evolving, thanks to the melding of cultures, shifts in the media we consume, and evolutions in our environment. These changes need not be feared—they can instead be bravely embraced.

While the Flynn Effect once clearly indicated signs of intelligence evolving across generations, the reverse Flynn Effect has complicated this narrative. 

To avoid the past historical implications the IQ test has left us with, it is critical to remain mindful that it isn’t the only measure of intelligence, even if it is currently a preferred measure. Furthermore, consider how a diversity of experiences, environments, and thought—which would also account for diversity in standardized test responses—can lead to an increasingly intelligent society.

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

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6. Bratsberg B, Rogeberg O. Flynn effect and its reversal are both environmentally caused. Proc Natl Acad Sci U S A. 2018;115(26):6674-6678. doi: 10.1073/pnas.1718793115

By Julia Childs Heyl, MSW

Julia Childs Heyl, MSW, is a clinical social worker and writer. As a writer, she focuses on mental health disparities and uses critical race theory as her preferred theoretical framework. In her clinical work, she specializes in treating people of color experiencing anxiety, depression, and trauma through depth therapy and EMDR (eye movement desensitization and reprocessing) trauma therapy.

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