The concept also proved useful to justify what was seen by some as the inevitable extermination of "the weaker races who disappear before the stronger" not so much "through the effects of …
our vices upon them" as "what may be called the virtues of our civilisation." Herbert Spencer's ideas, like those of evolutionary progressivism, stemmed from his reading of Thomas Malthus, and his later theories were influenced by those of Darwin.
The term was popularized in the United States in 1944 by the American historian Richard Hofstadter who used it in the ideological war effort against fascism to denote a reactionary creed which promoted competitive strife, racism and chauvinism.
Scholars debate the extent to which the various Social Darwinist ideologies reflect Charles Darwin's own views on human social and economic issues.
His writings have passages that can be interpreted as opposing aggressive individualism, while other passages appear to promote it.
A 'social Darwinist' could just as well be a defender of laissez-faire as a defender of state socialism, just as much an imperialist as a domestic eugenist.
The term draws upon the common use of the term Darwinism, which has been used to describe a range of evolutionary views, but in the late 19th century was applied more specifically to natural selection as first advanced by Charles Darwin to explain speciation in populations of organisms.