When drug or other therapeutic research reaches the stage when it is ready for human trial on a controlled, scientifically-observed experimental basis, particularly under conditions of segregation, the prison population is often turned to. Experimentation in jails and penitentiaries may be done without the prisoners knowledge and consent, or with consent but with little or no understanding of the risks involved. In some cases the experiments are dangerous, the risks being surgical mutilation, pharmaceutically or chemically induced organ impairment, or personality disorders.
During World War II, the Nazis experimented on prisoners in concentrations camps and the Japanese experimented on prisoners of war. Prisoners have been used in widespread fashion all over the USA in therapeutic drug trials and other medical and behaviour experiments.
In the 1960s, the USA treated prisoners' skin with chemical agents in the hope they would cause significant inflammation and crusting. The experimentation was to discover if skin could be toughened sufficiently to provide natural body armour for soldiers.
The consent of members of a captive population cannot be valid in that it is influenced by the hope of advantageous benefits such as earlier parole, and that it is purchased by this and other expectations rather than given freely.
Prisoners are particularly suitable subjects for medical experimentation in that they are living in a standard physical - and, indeed, psychological - environment; that they have the time to participate in long-term experiments that is not available to socially active populations; and that the prisoners themselves regard such participation as a means of escaping from the tedium of prison life, or demonstrating their social worth, and of earning a small income.