Terman defined “potential genius” as having an IQ of 140 and above, which is about 1 in every 250 people, while American psychologist Leta Hollingworth used as an even higher IQ threshold (180), which would translate to approximately 1 in every two million people. According to the Encyclopedia Britannica, in 1916 American psychologist Lewis M. That would be a bit like half of the people in this country thinking that they are in the top 1%.
