Quite often human experiments have been excessively brutal and violent. So be warned, the word “creepy” may be an understatement for some of the experiments on this list. Nonetheless, these are the 25 Incredibly Disturbing Science Experiments In History. The blue-eyed group got all-around preferential treatment (more food at lunch, more playtime, etc). Although it isn’t too surprising today, back then the results of this “experiment” were surprising…the brown-eyed kids actually started performing worse in school. It was a self-fulfilling prophecy. He received hormone injections and therapy sessions. Until the age of 14, David thought he was a girl named Brenda. The crazy part here is that the psychologist responsible for this advice, John Money, only wanted to use David as an experiment to prove that gender is due to nurture and not nature (he never told the parents his true intentions). David never quite felt like a girl, and at 14, his parents told him the truth. He immediately went back to being male. He took the name “David,” received injections of testosterone, a mastectomy, and a phalloplasty. Unfortunately, the ordeal ruined David and his family. His relationship with his parents was strained, his brother was depressed, and David eventually committed suicide. Note: this is because each person assumes that somebody else will do something or that everything is okay because nobody else is doing anything. And to make it worse, the actors often pleaded for the shocks to stop. Note: this study is famous for showing that, given the right circumstances, we are all capable of unspeakable atrocities.