Global Flynn Effect Reversal: IQ Declines Across Developed Nations

Cross-country data from Norway, Denmark, Finland, France, Britain, Australia and others show average IQ scores have declined since the mid-1990s by about five to seven points per generation, reversing the Flynn Effect. The reversal appears environmental rather than genetic, with potential contributors including schooling changes, screen time, nutrition, and social factors; U.S. results show declines in verbal and matrix reasoning but a rise in three-dimensional spatial rotation, suggesting a redistribution of cognitive skills rather than a simple drop in intelligence. The exact causes remain debated.