Francis Galton and Edgar Schuster
Galton wrote the (lengthy) introduction for this update to Hereditary Genius, while Schuster prepared the statistical data.
From the first chapter:
"THIS volume is the first installment of a work that admits of wide extension. Its object is to serve as an index to the achievements of those families which, having been exceptionally productive of noteworthy persons, seem especially suitable for biographical investigation.
The facts that are given here are avowedly bald and imperfect ; nevertheless, they lead to certain important conclusions. They show, for example, that a considerable proportion of the noteworthy members in a population spring from comparatively few families.
The material upon which this book is based is mainly derived from the answers made to a circular sent to all the Fellows of the Royal Society whose names appear in its Year Book for 1904.
The questions were not unreasonably numerous, nor were they inquisitorial; nevertheless, it proved that not one-half of those who were addressed cared to answer them. It was, of course, desirable to know a great deal more than could have been asked for or published with propriety, such as the proneness of particular families to grave constitutional disease. Indeed, the secret history of a family is quite as important in its eugenic aspect as its public history; but one cannot expect persons to freely unlock their dark closets and drag forth family skeletons into the light of day. It was necessary in such a work as this to submit to considerable limitations, while turning to the fullest account whatever could be stated openly without giving the smallest offence to any of the persons concerned.
One limitation against which I still chafe in vain is the impracticability of ascertaining so apparently simple a matter as the number of kinsfolk of each person in each specific degree of near kinship, without troublesome solicitations. It was specially asked for in the circular, but by no means generally answered, even by those who replied freely to other questions. The reason must in some cases have been mere oversight or pure inertia, but to a large extent it was due to ignorance, for I was astonished to find many to whom the number of even their near kinsfolk was avowedly unknown. Emigration, foreign service, feuds between near connections, differences of social position, faintness of family interest, each produced their several effects, with the result, as I have reason to believe, that hardly one-half of the persons addressed were able, without first making inquiry of others, to reckon the number of their uncles, adult nephews, and first cousins. The isolation of some few from even their nearest relatives was occasionally so complete that the number of their brothers was unknown. It will be seen that this deficiency of information admits of being supplied indirectly, to a considerable degree.
The collection of even the comparatively small amount of material now in hand proved much more troublesome than was anticipated, but as the object and limitations of inquiries like this become generally understood, and as experience accumulates, the difficulty of similar work in the future will presumably lessen."