Francis Galton, answered from the texts and cited to the page.
Men are not born equal in their natural powers, and the powers they are born with are inherited. I took the plainest test I could find: eminence — the reputation earned by a man who rises to the front rank of a difficult calling — and I traced the kinships of the eminent. I found what no theory of circumstance can explain: that the near relatives of the eminent man are themselves eminent far more often than chance allows, and that this density of ability in a lineage falls off with the distance of kinship exactly as a transmitted quality should.1
The judge's able son, the great family of divines or of naturalists — these are not the work of tuition, for tuition is poured out on thousands who never rise, and the humbly born man of true genius rises in spite of every disadvantage. Give me nature and nurture as the two contributions, and I say the evidence assigns to nature by far the larger part.
Education can polish and direct a faculty; it cannot create one where the seed was not sown. The man of genius is born with a cerebral constitution that the ordinary man simply lacks, and he transmits it, in some measure, to his descendants.234
My data afford an approximate estimate of the ratio, according to which effective ability (hereditary gifts plus education plus opportunity) is distributed throughout the different degrees of kinship. They state—(1) the number of kinsmen in the several near degrees; (2) the number of those among them who were in any 1.] ANTECEDENTS.English Men of Science, pp. 71–73
I will here mention Lord Lyttleton, Lord Keeper of Charles I., although many members of his most remarkable family do not fall within my limits. His father, the Chief Justice of North Wales,, married a lady, the daughter of Sir J. Walter, the Chief Justice of South Wales, and also sister of an English judge. She bore him Lord Keeper Lyttleton, also Sir Timothy, a judge.Hereditary Genius, p. 67
In reproducing them, as I now do, in a much more elaborate form, and on a greatly enlarged basis of induction, I feel assured that, inasmuch as what I then wrote was sufficient to earn the acceptance of Mr. Darwin (" Domestication of Species," ii. 7), the increased amount of evidence submitted in the present volume is not likely to be gainsaid.Hereditary Genius, pp. 2–3
He speaks of a wit that never failed him, and a suavity of temper that could never be ruffled, as peculiar qualities in which he, and indeed all his family (his immediate family), excelled most other men. The admirable description of Lord North by his daughter, Lady Charlotte Lindsay, that is appended to his biography by Lord Brougham, is sufficient proof of that lady's high ability.Hereditary Genius, pp. 81–82
Galton's Hereditary Genius founded the scientific study of individual differences and the whole hereditarian tradition in psychology, and the nature-nurture framing he coined still organizes the field. His specific method is now seen to have a deep flaw his critics pressed from the start: eminence tracks opportunity, wealth, education, and social connection as much as native gift, so the family clustering of eminence confounds inherited ability with inherited advantage — the objection Galton answered but did not dissolve. Modern behavior genetics, using the twin and adoption designs Galton himself pioneered, finds substantial heritability for measured cognitive ability while also finding large environmental effects and dense gene-environment interaction, so the mature verdict grants Galton that ability is partly heritable while rejecting his minimization of nurture and his reading of eminence as a clean measure of nature.