Test scores among young men declined between 1998 and 2003/04.
Secular declines in cognitive test scores: A reversal of the Flynn Effect
Teasdale TW, Owen DR. Intelligence. 2008;36:121–126.
Scores on cognitive tests have been very widely reported to have increased through the decades of the last century, a generational phenomenon termed the “Flynn Effect” since it was comprehensively documented by James Flynn in the 1980s. Data reported here from young adult males in Denmark show that whereas there were modest increases between 1988 and 1998, scores on all four tests declined between 1998 and 2003/2004.