We could have a real field day on this one, as we take a magnifying glass to previous U.S Presidents and their IQ’s. But before w e delve deeper we need to be crystal clear about one thing. The formal IQ test that we know and love today was only invented in 1905 A French psychologist called Alfred Binet. That being the case, one can only speculate what the ‘IQ’ of Presidents who reigned before that time was, and that is just what UC Davis professor Dean Simonton did back in 2006. In his groundbreaking study, Simonton used something called historiometrics to estimate what former President’s IQ’s would have been based on books they wrote, speeches they gave and the like. Interestingly, according to the modern day IQ scale, most former Presidents were pretty smart, relatively speaking and it seems they occupied The White House for good reason. Just bear in mind that the IQs presented here are estimates, and should be seen as such.