This question will be answered in two parts.
What US President had the Highest IQ?
In 2006, psychologist Dean Keith Simonton conducted what is called a historiometric study of the 42 US presidents from George Washington to George W. Bush in an attempt to estimate their IQs. He entered data from biographies detailing their educational backgrounds, personality descriptions, intellectual achievements, and accomplishments into a sophisticated software program designed to estimate IQs from such profiles, and he ranked them by IQ.
Since many arbitrary judgments are involved in quantifying cognitive characteristics, the specific IQ for any particular president should be taken as a very rough estimate at best. Changing input data by even a small amount would change significantly the estimated IQ. However, the value in this study resides in its comparison of the potential for achievement (IQ) with actual achievement. The table below lists, in descending order, the 10 presidents with the highest estimated IQ. Many presidents, like Washington at 20th (est. IQ 132.5) and Lincoln at 12th (est. IQ 140) who are not on this list, achieved significantly more than several who made the top ten, suggesting that performance in a role is not dependent on IQ alone. Simonton states, “Intellect is not, by any means, the only predictor of presidential leadership. Many other variables are involved as well, including both personality traits and situational factors.”
When we observe those who are articulate, we tend to judge them as highly intelligent, while those who lack verbal fluidity are perceived as intellectually limited. Of course, eloquence often derives from high intelligence but it’s not always the case. In high profile roles, like the US presidency, there is a premium on communication skills in creating an impression of intellectual power, while qualities like instinct and strategic decision-making are less observable and may escape inclusion in our personal assessment. For example, if we were able to administer IQ tests to those Presidents, we could expect some real surprises in discovering significant differences in their capacities for abstraction, problem solving and language comprehension. Consequently, we must move to certainty very carefully in our estimates of someone’s IQ.
The difficulty in estimating the IQs of the US Presidents was evident in Simonton’s study. Every US President had an estimated IQ of 130 or greater, placing them all in the top 3% of the general population in intelligence. For example, the estimate for the IQ of George W. Bush was 138.5, placing him in the top 0.9% of the population, but lower than most US Presidents. For a more detailed description of this study and some hints at U.S. Presidents at the lower end of the IQ scale see: Who was the Most Intelligent President in US History? – Intelligence and IQ
How did the IQ’s of the Most Intelligent U.S. Presidents compare with Einstein’s IQ?
Comparing the IQ’s of different people, based on their achievements is not the same as comparing their intelligence, because intelligence is a multi-faceted human attribute that involves many dimensions, such as imagination, creativity, and long-term problem solving ability that are not measured by an IQ test. People in different domains such as politics and science are particularly difficult to compare in intelligence because success in different fields draws upon different intellectual skills in addition to innate mental acuity.
Even comparing the intelligence of two mathematicians or physicists is difficult, because people in this field have differing as well as overlapping mental abilities. For example, John von Neumann was brilliant and was known for his quick problem-solving ability as well as his deep mathematical insight. Albert Einstein, on the other hand, seemed to be a person who solved deep problems by ruminating over a long period of time and using his imagination to “visualize” physics in his thought experiments. Consequently, the question “Who is the more intelligent, Von Neumann or Einstein” may be moot.
However, when we wish to compare imagined performance on a set of 45-minute IQ tests, we might have a better estimate of how various people might rank. Since IQ tests put a premium on speed, Einstein would probably not perform as well or as quickly as Von Neumann. Einstein would probably outperform all of the U.S. Presidents in his capacity for abstraction, so he would excel in the kinds of pattern recognition represented by Raven’s progressive matrices. Yet, some of the US Presidents, may have had a latent capacity for abstraction that was never manifest. For example, James Garfield discovered his own proof of the Pythagorean Theorem.
Furthermore, the brightest U.S. Presidents might outperform Einstein on the language portion of the tests (administered in English and German). For example the brilliant physicist, Richard Feynman was reported to have an IQ of only 125, that is generally attributed to his poor performance on the language portion of the IQ test.
So, the bottom line is that we have a general sense of the level of intelligence of people based on their achievements. However, such estimates are quite rough and comparisons among the very brightest are not feasible because intelligence has many different unmeasurable dimensions. Estimating IQ’s is probably more accessible (than estimating intelligence), because the skills measured in IQ tests are highly correlated with the kinds of skills involved in abstract thought required for mathematics, physics, and science in general. Since Einstein’s achievements derive from some of the dimensions of intelligence that are not measured by IQ tests, there are many brilliant people who would probably have a higher IQ score than Einstein, but most of them would not be as intelligent as he.
