Measuring the psychological traits of public figures, to be sure, has a sketchy history, but the psychologist Dean Simonton has developed several historiometric measures that are reliable and valid (in the psychometrician’s technical sense) and politically nonpartisan. He analyzed a dataset of 42 presidents from GW to GWB and found that both raw intelligence and openness to new ideas and values are significantly correlated with presidential performance as it has been assessed by nonpartisan historians. Though Bush himself is well above the average of the population in intelligence, he is third-lowest among the presidents, and comes in dead last in openness to experience, with a rock-bottom score of 0.0 on the 0–100 scale. Simonton published his work in 2006, while Bush was still in office, but the three historians’ surveys conducted since then bear out the correlation: Bush was ranked 37th, 36th, and 39th among the 42 presidents.
As for Vietnam, the implication that the United States would have avoided the war if only the advisors of Kennedy and Johnson had been less intelligent seems unlikely in light of the fact that after they left the scene, the war was ferociously prosecuted by Richard Nixon, who was neither the best nor the brightest. The relationship between presidential intelligence and war may also be quantified. Between 1946 (when the PRIO dataset begins) and 2008, a president’s IQ is negatively correlated with the number of battle deaths in wars involving the United States during his presidency, with a coefficient of −0.45. One could say that for every presidential IQ point, 13,440 fewer people die in battle, though it’s more accurate to say that the three smartest postwar presidents, Kennedy, Carter, and Clinton, kept the country out of destructive wars.
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