Drapetomania

Drapetomania was a conjectural mental illness that, in 1851, American physician Samuel A. Cartwright hypothesized as the cause of enslaved Africans fleeing captivity. Contemporarily reprinted in the South, Cartwright's article was widely mocked and satirized in the northern United States. The concept has since been debunked as pseudoscience and shown to be part of the edifice of scientific racism.
The term derives from the Greek δραπέτης ("drapetes", "a runaway [slave]") and μανία ("mania", "madness, frenzy").
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."
Description.
Cartwright described the disorder – which, he said, was "unknown to our medical authorities, although its diagnostic symptom, the absconding from service, is well known to our planters and overseers" – in a paper delivered before the Medical Association of Louisiana that was widely reprinted.
He stated that the malady was a consequence of masters who "made themselves too familiar with [slaves], treating them as equals".
In "Diseases and Peculiarities of the Negro Race", Cartwright says that the Bible calls for a slave to be submissive to his master, and by doing so, the slave will have no desire to run away.
Prevention and remedy.
In addition to identifying drapetomania, his feeling was that with "proper medical advice, strictly followed, this troublesome practice that many Negroes have of running away can be almost entirely prevented". 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".
Contemporary criticism.
While Cartwright's article was reprinted in the South, in the northern United States it was widely mocked. A satirical analysis of the article appeared in a "Buffalo Medical Journal" editorial in 1855. Renowned landscape architect Frederick Law Olmsted, in "A Journey in the Seaboard Slave States" (1856), observed that white indentured servants had often been known to flee as well, so he satirically hypothesized that the supposed disease was actually of white European origin, and had been introduced to Africa by traders.