The American President Believed To Have Had The Lowest IQ
Being the President of the United States is a job that requires at least a modicum of intelligence. As the most powerful man (or woman) in the world, the POTUS will face decisions that will set the course for the country, could have international consequences, and could even lead to peoples' deaths. Further, even getting elected president requires, at a minimum, a lengthy and successful career in politics, business, law, the military — things that also require a person of intelligence, at least, for that kind of longevity.
As it turns out, however, not every president has been the brightest bulb in the box. More than one man got the job simply by virtue of being in the right place at the right time (or the wrong place at the wrong time, depending on your point of view). And of course, it goes without saying that some of the men who have served in the Oval Office were less intelligent than their peers.
Measuring presidential intelligence
For decades, the psychology community has used the concept of IQ, or Intelligence Quotient, as a snapshot of someone's braininess. As a cultural and academic touchstone, it works: to say that someone has an IQ of 140, is to suggest that they're smart, while an IQ of 70 points toward intellectual disabilities.
There are two problems with this. First, as Scientific American notes, the notion that a single, standardized test can accurately portray someone's intelligence has been thoroughly debunked, to the point that assigning and discussing IQs is essentially meaningless. Second, determining a man's intelligence centuries after he's gone to his grave will necessarily involve a certain level of education guessing.
Nevertheless, in 2015, according to Money Wise, a researcher from the University of California at Davis looked at past presidents' decisions and other factors, and assigned each an IQ score. That research revealed a range of presidential IQs from the low 120s (the average IQ of a college graduate in the United States is 118) to well over 160 (above and beyond 130, which is considered the benchmark for a genius).
Ulysses S Grant was probably the least intelligent US president
Ulysses S. Grant was the 18th President of the United States, having served from 1869-1877. He was also the least intelligent, according to U.S. News & World Report, with an estimated IQ of 120 — which, though at the bottom of the list of presidents and their IQs, is still two points above the IQ of the average American college graduate.
As a boy, Grant was uninterested in school, and his classmates nicknamed him "Useless." Nevertheless, he appears to have found his stride academically, considering that he managed to get into, and graduate from, West Point (no mean feat then or now). Further, he fought on the winning side of the Civil War — "triumphantly" so, according to Money Wise.
However, his time in the Oval Office was marked by corruption and ineptitude, the most severe example of which was his failure to prevent the Panic of 1873, an event that kicked off a depression that saw millions of Americans become bankrupt — including Grant.