Over the weekend, President Trump took to Twitter to defend his sanity and intelligence:
Meeting with alarm and mockery alike, his unusual phrase “very stable genius” went viral. This sense of genius—an exceptionally intelligent or talented person—dates back to the 18th century, according to the Oxford English Dictionary (OED).
Drawing on the earlier work of Francis Galton, American psychologist Lewis Terman classified a score above 140 as near genius or genius on his 1916 Stanford-Binet Intelligence Test, historical basis of modern IQ scales. These now use language like very superior or extremely high for scores at or above 130, as genius is tricky to define scientifically. Etymologically, however, it’s a different story.