Ten of History’s Most Evil Science Experiments.

Civilization is indebted to science in a way that can never be repaid. The men and women who toiled away in their labs, testing hypotheses and challenging the status quo in an effort to prove a theory, discover a cure or explain the unknown have forever changed the world in which we live. As just one example, they’re the reason the average life expectancy has increased from 47 years in 1900 to 71 years today.

But not everyone who has donned the uniform of a lab coat is due gratitude. As with anything in life, lurking in the shadow of the good, you’ll find the bad. Sometimes the very bad. While some experiments led to discoveries which marked the birth of modern medicine, others serve to remind us of science’s darker side.

10. Project MKUltra

From 1953 until the project’s official suspension in 1973, the CIA conducted mind-control experiments on Canadian and U.S. citizens without their consent. Spread over a wide range of locations, including prisons, hospitals and universities, the covert experiments were also sanctioned by the Chemical Corps branch of the U.S. Army.

Using drugs such as LSD, amphetamines and barbiturates, the objectives of the experiments were to find a way to gain control of the subject’s mind as well as develop a chemical concoction that would serve as a truth serum. Other methods employed in the experiments included hypnosis and electroshock therapy.

At the time of the project’s end in 1973, most of the documents were destroyed by the CIA in an effort to keep the details hidden. It wasn’t until 1977, when some files stored in the wrong building were discovered, that the project came to light. As a result, the true extent of the damage done to the subjects remains unknown.

9. Penicillin Testing on Guatemalan Patients

In the mid-1940s, the United States government conducted a study to determine the efficacy of penicillin as a treatment for venereal diseases.

With prisoners, mental patients and soldiers in Guatemala City serving as unknowing test subjects, doctors infected them with various diseases and treated them with penicillin or orvus-mapharsen to determine which treatment offered the best results.

Because the experiment was designed to test the effect of different methods of treatment, not every patient received proper medical care. An estimated 83 people died as a result.

8. Radiation Exposure

We know now how dangerous radiation exposure is, but in the 1960s the Pentagon wanted to know just how much exposure the human body could withstand. With Dr. Eugene Saenger leading the experiment, cancer patients were told they would be receiving a different method of treatment that might possibly help them. Instead, the patients, all of whom were African-American, underwent a level of radiation exposure equivalent to more than 20,000 X-rays in just one hour.

At least 25 percent of the patients died because of the radiation exposure.

7. The Monster Study

A horrific example of the mistreatment of orphan children, the Monster Study was a 1939 research project conducted at the University of Iowa by graduate student Mary Tudor and supervised by her professor Wendell Johnson, who chose her to lead the project.

Using 22 children from an orphanage for veterans, two groups were created with the objective of determining whether verbal encouragement had any effect on treating stuttering. In one group, the children were given speech therapy and praised for their efforts while in the second group the children were harshly criticized and told not to speak if they couldn’t stop stuttering.

Only 10 of the 22 kids were identified as exhibiting some degree of the speech impediment, which meant children with normal speech patterns were led to believe they had an issue.

The long-term effects of the study was psychologically damaging to many of the children, with kids becoming withdrawn, depressed and developing lifelong speech-related problems.

6. Project 4.1

After a nuclear test conducted in 1954 unintentionally spread radiation to residents of the Marshall Islands, the U.S. government chose to monitor the effects of the exposure rather than immediately inform those affected. Among the effects of the radiation exposure were immediate hair loss, stillbirths and miscarriages in the first few years after the incident and, decades later, increased cancer diagnoses.

Though the exposure is officially documented as an accident, some believe it was an intentional abuse of an already marginalized group of people.