Research indicates potential reversal of the Flynn effect in IQ scores

Recent research suggests a potential reversal of the Flynn effect, a phenomenon where IQ scores rose steadily for nearly a century. While the original Flynn effect was attributed to improved nutrition, education, and complex environments, new data indicates a possible decline in cognitive test scores in certain populations.

A study led by Elizabeth Dworak of Northwestern University analyzed data from nearly 400,000 American adults tested between 2006 and 2018 via the SAPA research platform. The findings, published in the journal Intelligence, showed a decrease in general cognitive scores across various demographics, including age, sex, and education level. The most pronounced declines were observed in young adults aged 18 to 22 and individuals with lower education levels.

The decline is not uniform across all cognitive domains. While scores for abstract and logical reasoning have decreased, verbal reasoning remained relatively stable. Conversely, mental rotation abilities—the capacity to visualize and manipulate three-dimensional objects—have shown improvement. Researchers noted that these trends began prior to the rise of generative artificial intelligence and the COVID-19 pandemic. Some hypotheses suggest that increased video game popularity may influence these shifts, though this remains untested.