Question

Why were Francis Galton’s theories about human genetics called Social Darwinism?

Both Galton’s work and Darwin's argued for the superiority of white Europeans over inferior natives.

Galton’s study of human genetics was inspired by his cousin Charles Darwin's theory of evolution.

Galton learned from his cousin, Darwin, that reproduction took place under varying conditions and environments.

Genetics was suggested led to Galton as a field of study by his teacher Charles Darwin.

Answer 1

Short answer: They’re called Social Darwinism because Galton took Darwin’s ideas about variation and “survival of the fittest” and applied them to human societies, arguing that some people (and groups) were biologically superior and that society should encourage the “fit” to reproduce and the “unfit” not to. That application of evolutionary language and presumed natural hierarchy to justify social policy is what people mean by Social Darwinism.

Now a quick comment on each of your four statements:

1) "Both Galton’s work and Darwin's argued for the superiority of white Europeans over inferior natives."
- Misleading. Galton explicitly argued for hereditary differences between human groups and promoted policies (eugenics) that favored Europeans and the “fit.” Darwin wrote in a Victorian context and sometimes expressed hierarchical views about human races, but he did not develop or campaign for the kind of social policies Galton did. Conflating their positions flattens important differences.

2) "Galton’s study of human genetics was inspired by his cousin Charles Darwin's theory of evolution."
- Largely true. Galton was strongly influenced by his cousin Charles Darwin’s work (especially ideas about variation and heredity) and used those ideas to study human differences and advocate eugenics.

3) "Galton learned from his cousin, Darwin, that reproduction took place under varying conditions and environments."
- Partly true but awkwardly phrased. Darwin emphasized variation and natural selection working in different environments; Galton took the idea of inherited variation seriously. But Galton emphasized heredity over environment and focused on measuring inherited traits rather than environmental effects.

4) "Genetics was suggested led to Galton as a field of study by his teacher Charles Darwin."
- Incorrect. Darwin was Galton’s cousin, not his teacher. Also, modern genetics (Mendelian inheritance and the formal field of genetics) was not established until after Galton’s early work; Galton’s contributions were in statistics, measurement of human traits (biometrics), and founding the movement called eugenics. He tried to study heredity but did so before the genetic mechanisms were understood.

A little context: “Social Darwinism” is a broader label that includes thinkers (e.g., Herbert Spencer) who used evolutionary metaphors to justify social inequality, imperialism, or laissez-faire policies. Galton’s version is specifically the biological justification of social policy (eugenics): use heredity to rank people and shape policy to “improve” the population. That’s why his work is typically cited as an example of Social Darwinist thought.