Sir Francis Galton (February 16th 1822 with Sparkbrook, close to Birmingham - January 17th 1911 with Haslemere, in the Surrey) was a British scientist . One of the founders of the differential or compared Psychology, he is prize winner of the Royal Medal in 1886, of the Médaille Darwin in 1902, of the medal of money Darwin-Wallace in 1908 and of the Médaille Copley in 1910.

Biography

Cousin of Charles Darwin and high in a family of fortunate intellectuals (his grandfather is member of the Royal Society), Francis Galton did not make however brilliant studies at the university and if it attached his name to the Statistique and the Psychologie, it was before all touch-with-all of genius. Exploring impassioned, it obtains a first dedication as a Géographe, is interested enough in the Météorologie to bequeath us the word “Anticyclone” and invents the Sac of bed. As from 1865, it is devoted to the statistics with the objective to quantify the physical, psychic and behavioral characteristics of the man, like their evolution.

If Darwin stated his laws of the evolution in a context independent of any reflection on the calculation of the Probabilités, its theories ensured the triumph of a probabilistic description of the world, parallel to the statistical physics of Maxwell and Boltzmann. It is Francis Galton which established the link between the theory of the Natural selection and mathematical research, devoting a broad part of its activity to the defense of the Théorie of the evolution, while proposing to show that it allows forecasts likely to be checked.

Its studies relate to the transmission of hereditary features, as the size, and its more important contribution is to clarify correctly the concept of correlation, in other words the way in which the law of probability of a random variable depends on the presumedly fixed value of another random variable. Its work on the differential Psychologie is included from this point of view.

With its brilliant contributions mathematics, Galton joint of great talents of Organizing and Popularizer, animated there too consequently obsession: the systematic search for a scientific selection of the elite of humanity (or rather of the United Kingdom). For this reason, he is considered, with his disciple Karl Pearson, with whom he founds a newspaper devoted to this study ( Biometrika ), like the founder of a biometric school and eugenic British with the often worrying motivations.

Tests and quantification

The quantification of the biological observations is regarded by Galton as a requirement with their study. It applies this general principle to the study of the human capacities and uses with J. McKeen Cattell, the first tests.

These tests are tests relating to elementary, sensory and driving processes. Their validity with regard to complex criteria such as the university success will appear very low. Galton postulated that all biological measurements were to be distributed according to the normal law, a postulate that the conventional character of psychological measurements deprives, at least in this field, of precise significance.

He was the inventor many statistical methods usually employed since and of concepts in psychology like the calibration, the regression, the correlation. He outlined the principles of the factorial Analyze which will be developed in psychology in the directions that he had indicated by British psychologists such as C. Spearman and C. Bort. They will show that its intuition relating to the préminence of a general factor of intelligence on specific factors can constitute a heuristic manner to describe the individual differences in this field.

It was persuaded that the hereditary factors played a part dominating in the determination of the individual differences and outlined in this field of the methods of study of the problem heredity-medium which were since sophisticated: method of the twins, studies of pédigrés; but it underestimated in its work the importance of the factors of medium.

This orientation led it to defend of the principles eugenic which are not compatible with the values attached to the human rights in the modern democracies.

It founded in 1904 and financed a laboratory which was to be devoted to eugenic but which, become “Galton Laboratory” of the University of London, was directed later on by Karl Pearson and Ronald Fisher of which the contributions to the statistical methods are independent of the general orientations of Galton.

External bonds

• bibliographical Biography and reference to the numerical sources in project VLP of the Institute max Planck of history of sciences

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