Posted on April 3, 2023

New Study Reveals Sharp Decline in American IQ Scores

Tim McMillan, The Debrief, March 29, 2023

A new study found a sharp decline in American IQ scores in recent years, offering support for what researchers term the “Reverse Flynn Effect.”

Examining a large U.S. sample, researchers from Northwestern University found that IQ ability scores in three of four key categories dropped between 2006 and 2018. Composite ability scores (single scores derived from multiple pieces of information) were also lower in recent samples.

While a decline in IQ scores may sound alarming, researchers caution that the results do not mean Americans are becoming less intelligent.

“It doesn’t mean their mental ability is lower or higher; it’s just a difference in scores that are favoring older or newer samples,” said Dr. Elizabeth Dworak, a research assistant professor of medical social sciences at Northwestern University Feinberg School of Medicine and lead author of the new study.

“It could just be that they’re getting worse at taking tests or specifically worse at taking these kinds of tests.”

Additionally, researchers did find that American scores in the fourth key IQ category, spatial reasoning, had generally increased from 2011 to 2018.

Ultimately, results support a global decline in IQ scores beginning in the 1990s and 2000s. This phenomenon has become known as the “Reverse Flynn Effect.”

In his seminal 1984 study, American-born New Zealand intelligence researcher Dr. James Flynn found that beginning in the early 1930s, fluid and crystallized intelligence test scores have steadily increased in most of the world’s population.

Following Dr. Flynn’s initial work, the global increase in IQ test scores for most of the 20th century has been confirmed and termed the “Flynn Effect.”

And while the increase in intelligence test scores has been well documented, the exact reasons for the Flynn Effect remain one of modern psychology’s most ubiquitous and mysterious phenomena.

Because the Flynn Effect has been observed occurring over only a few generations, the increase in IQ scores cannot be attributed to genetic evolution. Instead, social scientists have concluded the basis for the phenomenon must stem from environmental factors. {snip}


After over a half-century of people becoming mysteriously smarter, recent research has unexpectedly revealed that global IQ scores seemingly peaked in the 1990s and have been in steady decline ever since.

Studies examining sample populations from Norway, Denmark, Australia, Britain, the Netherlands, Sweden, Finland, and now the United States have all shown statistically significant declines in IQ scores.

Scientists have termed this enigmatic IQ score decrease the “Reverse Flynn Effect.”


Some proposed explanations for the Reverse Flynn Effect are:

  • Worsening educational values and school systems
  • The proliferation of information systems (E.g., TV, the internet, social media, etc.) creates less intelligently stimulating environments.

The phenomenon’s namesake, Dr. Flynn, has suggested the decrease in teenage IQ scores in the United Kingdom could be “due to youth culture having “stagnated” or even dumbed down.”

Some notably controversial academics, like psychologist Richard Lynn, have tried to use the Flynn Effect as “evidence” to support pseudoscientific theories associated with biological racism or white racial superiority.

The Reverse Flynn Effect has been similarly co-opted by anti-immigration movements and pseudoscientific dysgenic or eugenic racist theories.