The most unethical scientific experiments in history illustrate what can happen when scientists neglect human rights, safety and basic morals. This description of cases illustrates how people and animals have been hurt for scientific purposes, ranging from Nazi experiments to the Stanford Prison Experiment. Some were forced participation; others involved causing physical and emotional harm to vulnerable persons.
There were also serious concerns about research ethics and informed consent raised by the Volkswagen emissions testing scandal and the use of Henrietta Lacks's cells. The knowledge of these illegal medical experiments makes one realize that there is a need to have strict rules and ethical standards in modern scientific experiments.
Volkswagen forced monkeys to inhale exhaust
You would think this might have occurred in the 20th century like the rest of the experiments in this slideshow, but this story is also relatively new. In 2014, German car maker Volkswagen held a test in which 10 monkeys inhaled diesel fumes from its cars in its attempt to prove that newer diesel engines do not produce as much toxic fumes as their previous models, while also helping out the company and they tampered with the diesel vehicle to make it less toxic than normal as well.
The Push
Did mentalist Derren Brown cross the line in an attempt to show that he could get a person to commit murder? Can human beings feel pressured into a murder? This is the starting point for the Netflix reality show The Push, which premiered February 2018. The experiment employs 70 actors in one of the most elaborate and insidious plots to make a person push a man to his death.
The show follows Chris, a normal young guy whose life takes a true descent into hell. Will he go through with it? The experiment is so macabre that the subject must be thinking about suing the hell out of the network.
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The Stanford Prison Experiment

In 1971, the American psychologist Philip Zimbardo sought to show that some social environments are capable of producing behaviours that clash with people's own moral standards, especially in prisons.
He randomized eighteen voluntary participants into two groups - prisoners and guards. Almost as soon as the researchers assigned these roles, the prison guards exercised this newfound authority with prejudice, and the prisoners submitted to this brutal treatment despite the fact that they could have withdrawn from the study at any time.
The Aversion Project
Under apartheid, the South African military prohibited homosexuality, and Dr. Aubrey Levin "treated" men via the Aversion Project, a program he ran that reportedly involved 900 homosexuals and used forced gender reassignment surgery, electric shock treatment, and chemical castration to produce a homosexual "aversion."
After fleeing to Canada, authorities convicted Levin of multiple counts of sexual assault by over 20 of his male patients and sentenced him to five years in prison in 2013. Conversion therapy continues to be utilized today to oppress and suppress sexual orientation, despite the United Nations proving it to be ineffective, abusive, and "dangerous and discredited" in 2015.
Slaves as guinea pigs
James Marion Sims (the father of gynecology and the father of the speculum, that thing you feel in your vagina that's cold and uncomfortable) experimented on black slave women in 19th-century United States. His subjects did not consent, of course, for there was no such thing as informed consent. They were not about to say no to a man who owned them.
Nazi experiments
In the Holocaust, Josef Mengele used Jewish prisoners – primarily twins – as guinea pigs for his experiments to reveal the significance of heredity, supporting Nazi emphasis on Aryan race superiority. Regarded as the Angel of Death, Mengele abused his patients and caused the deaths of many others; he performed amputations and deliberately injected them with diseases. After the war, the Nuremberg Code defined medical practices which are 'acceptable' for use in experimentation, albeit the Nazi butcher was later able to avoid trial and died in 1979 in Brazil.
The Monster Study
In 1939, researchers conducted an experiment on stuttering and language acquisition with 22 Iowa orphans. The researchers divided the children, all orphans, into two groups, with each receiving a different type of therapy - positive and negative. One group received praise and congratulations whenever they spoke fluently, while the other group faced scorn for any mistakes they made.
Some of the children in the negative condition never overcame their speech impediments and spent the rest of their lives with both the effects of their speech impediments and the psychological scars they left. Dr. Wendell Johnson, the author of the experiment, and his peers later referred to it as the Monster Study due to its horrifying nature. In 2007, the University of Iowa provided monetary compensation to seven of the test subjects for the trauma they experienced.
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Stolen cells
Henrietta Lacks' cells valued at gold. They played a significant role in scientific research, from the creation of a vaccine for polio to the sequencing of the human genome. Sadly, an African-American woman who succumbed to an aggressive form of cancer in 1951 did not live to benefit from the origin of her cells, which researchers collected as an organ donor without her knowledge.
Her family only learned some 25 years later that Lacks' body had been an important contributor to science, with no remuneration, and they filed a case in 2023 with biotech giant Thermo Fisher Scientific Inc for using Lacks' cancer cells to generate outrageous profits without her family's permission.
FAQs
1. What are the most unethical scientific experiments in history?
Some widely discussed examples include Nazi medical experiments, the Stanford Prison Experiment, the Monster Study, the Aversion Project, and research involving Henrietta Lacks' cells.
2. Why were these scientific experiments considered unethical?
Many involved a lack of informed consent, physical or psychological harm, coercion, discrimination, or the exploitation of vulnerable people.
3. What was the Stanford Prison Experiment?
Conducted in 1971 by psychologist Philip Zimbardo, this study examined the effects of assigned prison roles. It became controversial because of participant distress, ethical concerns, and questions about its scientific methods.
4. What happened in the Monster Study?
In 1939, researchers studied speech and stuttering in 22 children at an Iowa orphanage. Some children received negative feedback about their speech, raising serious concerns about psychological harm and research ethics.
5. How have unethical scientific experiments changed research rules?
Historical abuses helped strengthen informed consent requirements, independent ethics reviews, participant protections, and standards for responsible scientific research.

