"Massive IQ Gains in 14 Nations: What IQ Tests Really Measure" by James R. Flynn in Psychological Bulletin. Here is the correct APA citation form, modernized with the doi reference:<p>Flynn, J. R. (1987). Massive IQ gains in 14 nations: What IQ tests really measure.  Psychological Bulletin, 101, 171-191. doi: 10.1037/0033-2909.101.2.171<p>URL:<p><a href="http://psycnet.apa.org/journals/bul/101/2/171.html" rel="nofollow">http://psycnet.apa.org/journals/bul/101/2/171.html</a><p>This was a path-breaking paper, which, as N.J. Mackintosh comments, introduced many psychologists to long-ignored data that could have been noticed long ago: "the data are surprising, demolish some long-cherished beliefs, and raise a number of other interesting issues along the way."