Final answer:
The four different strands of eugenics that developed by the beginning of the 1900s were: Medical Exploitation, Racism and Xenophobia, Genetic Superiority, and Disability Discrimination.
Step-by-step explanation:
The four different strands of eugenics that developed by the beginning of the 1900s were:
- Medical Exploitation: This strand focused on forced sterilization programs and the belief in negative genetic traits of certain groups.
- Racism and Xenophobia: This strand promoted forced sterilization as a way to maintain racial purity and prevent the spread of disease.
- Genetic Superiority: This strand aimed to create genetically superior humans through selective breeding and improving the genetic makeup of the human race.
- Disability Discrimination: This strand sought to discourage childbearing among people with disabilities through laws prohibiting marriage and forced sterilization.