At least one historian has suggested that Sumner was possibly on the autism spectrum, noting that his “ability to hyperfocus on a specific topic,” among other personality traits, was a classic sign of what some psychologists have categorized as Asperger syndrome. While any attempt to diagnose Sumner retroactively is foolhardy, it is difficult to think that such a diagnosis would be completely unmerited given some of his childhood behaviors. For example, at the age of fourteen, Sumner made an eighty-six-page chronological list of major events in English history—not for school, but for fun.
