Eugenics
Who- hitler, other people who used misused early studies of genetics
What- Eugenics is when a society or group of people control the genes that are allowed to be passed on to the next generation be sterilizing those who are considered to have inferior genes.
When- 1900's
Where- this happened in nazi Germany when hitter tried to exterminate all Jewish people because he believed they were inferior to his superior race. It also happened in America in the 1930's when 25,000 people where sterilized due to them having mental illness.
Why- this happened because of a misinterpretation of how people gain their traits by assuming that everything about you is genetic.