Using Human Beings as Laboratory Animals
The true nature of the experiment had to be kept from the subjects to ensure their cooperation. The sharecroppers' grossly disadvantaged lot in life made them easy to manipulate. Pleased at the prospect of free medical care —almost none of them had ever seen a doctor before— these unsophisticated and trusting men became the pawns in what James Jones, author of the excellent history on the subject, Bad Blood, identified as “the longest non-therapeutic experiment on human beings in medical history.”
The study was meant to discover how syphilis affected blacks as opposed to whites —the theory being that whites experienced more neurological complications from syphilis, whereas blacks were more susceptible to cardiovascular damage. How this knowledge would have changed clinical treatment of syphilis is uncertain.