According to Darwin’s theory of evolution, only the plants and animals best adapted to their environment will survive to reproduce and transfer their genes to the next generation. Animals and plants that are poorly adapted to their environment will not survive to reproduce.

Charles Darwin published his notions on natural selection and the theory of evolution in his influential 1859 book On the Origin of Species.

Darwin’s theory of evolution by natural selection was a scientific theory focused on explaining his observations about biological diversity and why different species of plants and animals look different.

Yet in an attempt to convey his scientific ideas to the British public, Darwin borrowed popular concepts, including “survival of the fittest,” from sociologist Herbert Spencer and “struggle for existence” from economist Thomas Malthus, who had earlier written about how human societies evolve over time.

Darwin rarely commented on the social implications of his theories. But to those who followed Spencer and Malthus, Darwin’s theory appeared to be confirming with science what they already believed to be true about human society—that the fit inherited qualities such as industriousness and the ability to accumulate wealth, while the unfit were innately lazy and stupid.

After Darwin published his theories on biological evolution and natural selection, Herbert Spencer drew further parallels between his economic theories and Darwin’s scientific principles.

Spencer applied the idea of “survival of the fittest” to so-called laissez faire or unrestrained capitalism during the Industrial Revolution, in which businesses are allowed to operate with little regulation from the government.

Unlike Darwin, Spencer believed that people could genetically pass learned qualities, such as frugality and morality, on to their children.

Spencer opposed any laws that helped workers, the poor, and those he deemed genetically weak. Such laws, he argued, would go against the evolution of civilization by delaying the extinction of the “unfit.”

Another prominent Social Darwinist was American economist William Graham Sumner. He was an early opponent of the welfare state. He viewed individual competition for property and social status as a tool for eliminating the weak and immoral of the population.

As social Darwinist rationalizations of inequality gained popularity in the late 1800s, British scholar Sir Francis Galton (a half-cousin of Darwin) launched a new “science” aimed at improving the human race by ridding society of its “undesirables.” He called it eugenics.

Galton proposed to better humankind by propagating the British elite. He argued that social institutions such as welfare and mental asylums allowed inferior humans to survive and reproduce at higher levels than their superior counterparts in Britain’s wealthy class.

Galton’s ideas never really took hold in his country, but they became popular in America where the concepts of eugenics quickly gained strength.

Eugenics became a popular social movement in the United States that peaked in the 1920s and 1930s. Books and films promoted eugenics, while local fairs and exhibitions held “fitter family” and “better baby” competitions around the country.

The eugenics movement in the United States focused on eliminating undesirable traits from the population. Proponents of the eugenics movement reasoned the best way to do this was by preventing “unfit” individuals from having children.

During the first part of the 20th century, 32 U.S. states passed laws that resulted in the forced sterilization of more than 64,000 Americans including immigrants, people of color, unmarried mothers and the mentally ill.

Adolf Hitler, one of the world’s most notorious eugenicists, drew inspiration from California’s forced sterilizations of the “feeble-minded” in designing Nazi Germany’s racially based policies.

Hitler began reading about eugenics and social Darwinism while he was imprisoned following a failed 1924 coup attempt known as the Beer Hall Putsch.

Hitler adopted the social Darwinist take on survival of the fittest. He believed the German master race had grown weak due to the influence of non-Aryans in Germany. To Hitler, survival of the German “Aryan” race depended on its ability to maintain the purity of its gene pool.

The Nazis targeted certain groups or races that they considered biologically inferior for extermination. These included Jews, Roma, Poles, Soviets, people with disabilities and homosexuals.

By the end of World War II, social Darwinist and eugenic theories had fallen out of favor in the United States and much of Europe—partly due to their associations with Nazi programs and propaganda, and because these theories were scientifically unfounded.

Social Darwinism; American Museum of Natural History.
America’s Hidden History: The Eugenics Movement; Nature. September 18, 2014.
In the Name of Darwin; PBS.
Victims of the Nazi Era: Nazi Racial Ideology; United States Holocaust Memorial Museum