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The Most Evil Human Trials in the History of Science

Dosing, syphilis, and learned stuttering.
​A doctor draws blood from one of the Tuskegee test subjects. ​Wikimedia Commons

Maybe you've taken part in a clinical study before, either because you're especially noble or you needed ten bucks for your next case of beer. Whatever the reason, congratulations! It's commendable when people voluntarily make themselves available to further science.

However, it can be difficult to find volunteers for certain experiments. For example, when it's a study about the effects of sexually transmitted diseases left untreated. Or when it's about how quickly someone dies when he or she is spun in a circle for long enough. But all these horrible things have actually been tested. Over the last decades, people have performed awful experiments on each other. It's a horror that exists on the spectrum of "still relatively harmless" to "incredibly excruciating," but no matter what, it's always hard to imagine.


The monster study

The speech therapist Wendell Johnson hypothesized that the development of a stutter is relative to how other people react to harmless speech impediments. His student, Mary Tudor, led a study in 1939 on 22 orphans.

Her job was to make half of the children stutter by correcting each and every little mistake, thus making them feel insecure. She explained to the children how horrible they sounded while simultaneously warning them: "Listen, if you start stuttering at one point, it will inevitably continue and get worse. So you better just say nothing at all if you can't speak correctly!"

Even the children who originally lacked even the slightest speech impediment, soon didn't dare to speak in class. A nine-year-old named Betty Hull would just silently cover her eyes with her hands when she was asked a question. Another girl, Mary Korlaske, was asked if her best friend knew she had a stutter. "No," she replied. "Why not?" the researcher asked. Mary uneasily pawed the ground with her feet and answered that she says almost nothing to her friend at this point.

After the experiment was over, Mary Hull explained to the children that their speech was fine, but the damage was irreversible. Mary Korlaske never learned to speak correctly again. And yet this mean-spirited test contributed a lot to our understanding of stuttering.

The Tuskegee syphilis experiment

From 1932 to 1972, the US Public Health Service, working with the Tuskegee Institute, conducted research on untreated syphilis. In the study, 399 poor farmers from Alabama, two thirds of whom were diagnosed with syphilis, were tracked over years.


In 1940, we already knew that syphilis can be easily cured with penicillin. The doctors wanted to see how the disease would develop without the use of modern pharmacology. Complimentary doctor's visits, which the farmers would normally not be able to afford, were offered to get them to donate blood. A warm meal was provided after each examination as bait.

Since all the farmers were black and all the doctors were white, the study was not only unethical, but also deeply racist. Twenty-eight of the 399 infected persons died of the disease; 100 more died of indirect complications from syphilis.

The syphilis experiment in Guatemala

While researching the Tuskegee Experiment in 2005, Susan Teverby stumbled on a way worse experiment that the US conducted between 1946 and 1948 in Guatemala. These trials didn't make use of people who were already infected with STDs. The subjects were actively infected with syphilis, gonorrhea, and chancroid. The aim was to more accurately understand the effects of penicillin.

Infected prostitutes were paid to have sex with prison inmates

For the experiment, infected prostitutes were paid to have sex with prison inmates in order to infect them. Guatemalan soldiers and psychiatric patients were additionally used as subjects. Some of them had pathogens injected directly into their bloodstream.

Eighty-three people were killed in this way. In 2010, Hillary Clinton and Kathleen Sebelius officially apologized for the American government's atrocities. Barack Obama also offered an apology to the Guatemalan president.


Project Mk-ultra

In the 1950s, there was a permanent sense of paranoia looming in the air. The uneasy atmosphere of the Cold War inspired the CIA to conduct countless experiments with the aim of developing methods to weaken a person's mental state so that they'd no longer be in a position keep information to themselves.

These experiments included administering various drugs, hypnosis, and even sexual abuse. Since basically all the relevant CIA documents were destroyed in 1973, the bulk of the project will never see the light of day.

An important part of the project was ​testing LSD on unknowing prisoners, drug addicts, persons with phycological disorders, and prostitutes. In one known case, a patient was given LSD for 174 days in a row. In another experiment, tripping patients were exposed to glaring light. They were told their bad trips would continue into eternity if they didn't divulge their deepest secrets.

The CIA also had big plans for dosing heads of state like Fidel Castro. To plan these kinds of operations, they needed to see what LSD does under totally normal conditions. So they slipped LSD into the morning coffee of unsuspecting CIA employees. Some of them went crazy from these surprise trips. For example, one man psychotically ran through the streets of Washington, seeing monsters sitting in all the cars he past. Another jumped from the thirteenth floor to his death. The experiments continued regardless.


Ultimately, this pioneering work yielded the conclusion that effects of LSD are unpredictable and therefore it's not especially good for controlling the human mind.

Nazi experiments

​Twins in Auschwitz who were kept alive for Mengele's experiments. Image: Wikimedia Commons, USHMM/Belarusian State Archive of Documentary Film and Photography, public domain

If we're talking about crimes against humanity, the Nazis are obviously at the top of the list. To put it more precisely, it doesn't really get any worse.

The following horrific experiments, among others, were conducted by Eduard Wirths and Josef Mengele:

  • Twins and half-siblings were sewn together to see if "a new creature" could thereby be created.
  • To study the effects of cold, people were thrown into ice water while researchers noted how exactly they died. They primarily "utilized" Russian prisoners of war, because the Germans were worried that the Russians had a genetic resistance to cold.
  • For their tests with seawater, the Nazis locked 90 Gypsies without food or drinking water in a room, only giving them a bucket of saltwater to drink. The victims got so horribly dehydrated, that they began licking the floor in utter despair after it had just been freshly mopped (the Nazis were completely obsessed with immaculate hygiene).
  • In 1933, a law was passed that forced people with potential genetic disorders to be sterilized. If you weren't a perfect Aryan, you didn't have the right to exist and you definitely didn't have the right to reproduce. To find out the most effective way to sterilize people, they conducted thousands of horrible experiments.
  • This list could continue on forever. And on top of it, it turns out that Josef Mengele was notoriously incompetent and had no idea what he was doing when it came to medical procedures.


Unit 731

Unit 731 premises. Image: Wikimedia Commons CC BY-SA 3.0

Unit 731 isn't just a Slayer song, it was also one of the Japanese army's infamous research complexes, where people were experimented on during both the Second Sino-Japanese War and WWII. The microbiologist, Shiro Ishii, was the mastermind behind it—a man who even Josef Mengele could have learned a lot from when it comes to viciousness.

Vivisection without anesthetics; freezing, then thawing and amputating limbs

Among other things, these horrific proposals were included Ishii's repertoire: Vivisection without anesthetics; freezing, then thawing and amputating limbs (also without anesthetics). The victims' amputated arms and legs were sewn back onto the other side. They were injected with animal blood and seawater, infected with STDs and spun in a circle until they died. For weapons tests, the perpetrators placed their poor victims at various distances around a grenade—the grenade was then detonated.

The Japanese used Chinese people as guinea pigs for the development of biological weapons. Low-flying planes bombarded Chinese cities and villages with plague-infected flies. The only problem was that the swarms ended up drifting through the air and infecting their own troops, which lead to the experiment being terminated after the first large-scale tests.

After Japan surrendered in 1945, a plane full of Americans landed at the complex. The soldiers became dizzy after seeing all the atrocious ghoulishness, but with the backdrop of the arms race with the Soviet Union, not necessarily out of compassion. Having the key to the Unit 731 files, Shiro Ishii offered the Americans a deal: He and his men could stay alive in exchange for the files. He died at the age of 67 from natural causes, having never spent a single day in jail.

The Soviet Union, North Korea and other regimes are also guilty of conducting heinous experiments on people. But let's conclude here with some good news: Nowadays there are conventions, ethical principles and codes that prevent this type of treatment, for example the Declaration of Helsinki. And the bad news here at the very end: These agreements are still broken all the time (for example, by the CIA).

​This story was translated from ​Motherboard Germany.