Study says American adults are not as smart as they were twelve years ago

Shifts in cognitive abilities should have significant implications for education, workforce development, and public policy in the wake of a study that has shown a decline in IQ scores among U.S. adults, over twelve years.

Conducted by researchers from Northwestern University and the University of Oregon, the study analyzed data from the Synthetic Aperture Personality Assessment Project (SAPA Project), involving nearly 400,000 participants from 2006 to 2018 and found a decline in cognitive abilities

The findings, published in the journal Intelligence, indicate a reverse Flynn effect in several cognitive domains.

The Flynn effect, named after intelligence researcher James Flynn, refers to the significant rise in IQ scores throughout the 20th century. However, this study suggests a reversal of that trend in the 21st century for U.S. adults.

The researchers observed a decline in composite cognitive ability scores and specific domain scores such as matrix reasoning, letter and number series, and verbal reasoning. These declines were consistent across different ages, education levels, and genders.

The study’s most significant declines were found in participants aged 18-22 and those with lower educational attainment.

On average, IQ scores in the declining domains fell by up to 2 points. Conversely, the domain of three-dimensional rotation, which assesses spatial reasoning, showed an increase in scores from 2011 to 2018, suggesting a continued Flynn effect in this specific area.

Lead author Elizabeth Dworak noted that the findings are consistent with similar research in European countries, which has also documented declining IQ scores since the turn of the millennium.

The reasons behind these trends remain speculative, but some researchers attribute the decline to the pervasive use of technology. The argument is that reliance on smartphones, GPS, and other smart devices might be reducing the need for cognitive skills that were previously exercised more frequently.

Psychologist Ruth Karpinski from California commented on this hypothesis, suggesting that technology has made cognitive tasks so easy that people are not challenging their brains as much as they used to. This cognitive laziness could be a contributing factor to the observed decline in IQ scores.

Despite these findings, the study has limitations. The online nature of the SAPA Project means that test conditions were not controlled, and the sample was somewhat better educated than the general U.S. population. Additionally, a 2018 article in the Washington Post led to an influx of older test-takers, potentially skewing the results.

The study adds to the ongoing debate about the validity and implications of IQ testing. Some experts argue that the Flynn effect undermines the notion of IQ as a fixed measure of innate intelligence.

Instead, they suggest that rising and now falling IQ scores may reflect changes in environmental factors such as education, nutrition, and the complexity of daily life.

As researchers continue to investigate these trends, the study’s authors emphasize the need for further research to pinpoint the exact causes and broader implications of the reverse Flynn effect.