He had a keen eye for human nature, but sometimes went overboard in his interpretation of people’s looks. When he encountered several Confederate prisoners, Oliver Wendell Holmes questioned them at length, asking why they fought against the nation that had given them birth. He received conflicting answers, none truly satisfactory, then noticed another prisoner, who he decided was the “true Southern type.”

“A fine fellow, a little over twenty, rather tall, slight, with a perfectly smooth, boyish cheek, delicate, somewhat high features, and a fine, almost feminine mouth.” When the Northern man asked the Southern one why he fought, the answer came soft but deliberate: “Because I like the excitement of it.” Holmes went on to write that he knew those men with soft, delicate features and mouths who looked as if they belonged to women: men such as these were natural-born killers.