Drapetomania

Drapetomania was a proposed mental illness that, in 1851, American physician Samuel A. Cartwright hypothesized as the cause of enslaved Africans fleeing captivity.

[1]: 41 [2] This hypothesis was based on the belief that slavery was such an improvement upon the lives of slaves that only those suffering from some form of mental illness would wish to escape.

[9] As late as 1914, the third edition of Thomas Lathrop Stedman's Practical Medical Dictionary included an entry for drapetomania, defined as "vagabondage, dromomania; an uncontrollable or insane impulsion to wander.

If any one or more of them, at any time, are inclined to raise their heads to a level with their master or overseer, humanity and their own good requires that they should be punished until they fall into that submissive state which was intended for them to occupy.

[9] In the case of slaves "sulky and dissatisfied without cause"—a warning sign of imminent flight—Cartwright mentioned "whipping the devil out of them" as a "preventative measure".