IQ: The Debate Rages On

In an article in the August 2006 issue of the journal Political Psychology entitled "Presidential IQ, Openness, Intellectual Brilliance, and Leadership: Estimates and Correlations for 42 U.S. Chief Executives," Dean Keith Simonton, a psychologist at the University of California, Davis, estimated the IQs of the 42 presidents based on their writings, early developmental milestones, openness to ideas, and other traits generally linked to intelligence; he also drew on previous studies by other researchers. All the presidents scored at least 130, in the top 2.2 percent of the population. Simonton found that John Quincy Adams, who only lasted one term, was the smartest president, with an estimated IQ of 175, while the lowest, Ulysses Grant scored 130 yet won the Civil War; President George W. Bush scored 138.5.

Simonton argues that while George W. Bush's estimated IQ is below average when compared to those of other chief executives, he is "certainly smart enough to be president of the United States."