Lambert Adolphe Jacques Quetelet

Born Feb. 22, 1796, in Ghent; died Feb. 17, 1874, in Brussels. Belgian mathematician, astronomer, meteorologist, and sociologist; one of the creators of scientific statistics.

Quételet became a professor of mathematics and astronomy in Brussels in 1819. In 1820 he became a member of the Belgian Royal Academy of Sciences and in 1834, its secretary. Beginning in 1832 he was director of the astronomical and meteorological observatory founded by him in Brussels. From 1841 to 1874 he was chairman of the Central Belgian Statistical Commission, which had been established on his initiative. He was also the organizer of the first international statistical conference (Brussels, 1853) and chairman of the first international meteorological conference—the Conference on Marine Meteorology (1855). He carried out extensive studies of the climate of Belgium and of the entire globe. He was also the author of Elementary Astronomy, reprinted five times (1826–48).

From the standpoint of positivism, Quételet asserted that social and physical phenomena are subordinate to identical laws and must be studied by the precise methods of mathematical statistics. He set forth the concept of the “average man” (homme moyen), possessing average physical, intellectual, and moral characteristics. Separate individuals, in Quételet’s opinion, are only distorted expressions of the average type. Quételet attempted to discover the laws of its preservation. He proved that certain mass social phenomena (such as birth, death, crime) are subject to definite patterns. K. Marx appraised Quételet’s book On Man and the development of His Faculties, or An Experiment in Social Physics (vols. 1–2, 1835) as an “excellent scientific work” (see K. Marx and F. Engels, Soch., 2nd ed., vol. 8, p. 531), but he noted that Quételet was unable to explain the regularities he himself had established (ibid., vol. 32, pp. 495–96).

Quételet exercised considerable influence on the development of quantitiative methods in social studies.