Many brilliant minds in history displayed traits we now tie to autism spectrum disorder: intense focus, social oddities, and unique thinking. Before autism was identified in the 20th century, these were often called eccentricity or genius. Psychiatrist Michael Fitzgerald, in a 2008 study in the Journal of Autism and Developmental Disorders, argues that such traits appear often among exceptional figures, hinting some might have been autistic. Here’s a look at 39 whose behaviors suggest they could have been on the spectrum.