Adolphe Quetelet

Lambert Adolphe Jacques Quetelet ( born February 22, 1796 in Ghent, † February 17, 1874 in Brussels) was a Belgian astronomer and statistician.


After his father died early in 1803, Adolphe Quetelet had to deal at a young age with the development of its own existence. Quetelet studied in Ghent and in 1815 professor of mathematics. At the University of Ghent, he puts his 1819 dissertation on conic sections before, De quibusdam locis geometricis nec non de curva focali.

In 1819 he was for a short time at the Athenaeum to Brussels and on 24 February 1820, the Académie Royale des Sciences et Belles Lettres de Bruxelles, where he is also professor of astronomy and mathematics at the Military Academy in 1836. Since 1826 Quetelet worked at the Belgian National Statistical Office. In 1828 he became director of the observatory established under his leadership, the Observatoire Royal de Belgique.

His work in the State Statistical Office and the acquaintance with the mathematician Pierre- Simon Laplace in Quetelet aroused interest in the theory of probability. He tried to apply this knowledge to new areas, such as meteorology and terrestrial magnetism.

Since 1820 he was a member, since 1834 permanent secretary of the Royal Netherlands Academy of Sciences. Quetelet in 1841 was appointed President of the Central Statistical Commission for Belgium.

A great reputation Quetelet had acquired especially through its social statistics and anthropometric work. He tried to fathom both the physical and the moral phenomena of individual and community life. He often went over purely mechanically, his methods have been questioned during his lifetime. So he conducted a study on the distribution of the values ​​of human breast circumference. The values ​​observed at 5,738 Scottish soldiers led to a normal distribution.

Quetelet continued to seek after statistical particularities of the life expectancy or characterological and social characteristics as the propensity for writing or for crime. He discovered that many of these properties are normally distributed. Quetelet summed this up together with the ideal type of the middle man ( homme moyen French ). This he called he founded knowledge area social physics.

He founded several scientific societies and tried to improve the international exchange among scientists from different countries. Quetelet is considered today as the founder of modern social statistics. Among other things, he organized the first census in 1846 in Belgium. In 1854 he was appointed foreign member of the Bavarian Academy of Sciences.

On September 20, 1824 married Cécile Quetelet Virginie Curtet, the daughter of French physician François- Antoine Curtet in Brussels. Her salon was later turned into a meeting place of many scholars and artists of international renown.

Lambert Adolphe Jacques Quetelet died on 17 February 1874 in Brussels, where he was in 1880, the Belgian Academy erected a monument ( a seated marble figure of Charles Auguste Fraikin ).


Quetelet's studies on human bodies had great influence on Alphonse Bertillon, who on his investigations created based the foundations of his later Bertillonage mentioned system for personal identification.

In his Quetelet body anthropometry indicators developed for the " average " people, of which the Quetelet index (Body Mass Index ) is used to this day.

Its great merit is to have provided evidence that the seeming accidents of social life through their periodic repetition and their periodic averaging possess an inner necessity. However, Karl Marx missed an interpretation thereof.

Single Documents


  • Astronomy élémentaire, 2 vols, Brussels 1826
  • Positions of Physics, 3 vols, Brussels 1827 (French reprint 2010)
  • Recherches sur la reproduction et la mortalité et sur ​​la population de la Belgique, Brussels 1832
  • Statistique de la Belgique of tribunaux, Brussels 1833
  • (Ed.) Annales de l' Observatoire de Bruxelles, Brussels 1834 ff
  • (Ed.) Annuaire de l' Observatoire Royal de Bruxelles, Brussels 1834 ff
  • Sur l' homme et le développement de ses facultés, ou essai de physique sociale, 2 vols, Paris 1835 (English About the people and the development of his skills in 1838; . Engl A treatise on man and the development of his faculties )
  • Sur l' influence des saisons sur la mortalité aux differens ages dans la Belgique, Brussels 1838
  • Sur la théorie the probabilites apliquée aux sciences morales et politique. Lettres au duc de Saxe -Coburg Gotha et, Brussels 1846
  • You système et sociale des lois qui le régissent, Paris 1848
  • Sur le climat de la Belgique, 2 vols, Brussels 1849-1857
  • Théorie des probabilites, Brussels 1853
  • Histoire des Sciences Mathématiques et physiques chez les Belges, Brussels 1864
  • Science Mathématiques et physiques chez les Belges au commenceent you 19e siècle, Brussels 1866
  • Physique sociale ou essai sur le développement de l' homme of facultés, Brussels 1869
  • Anthropometry ou mesure de l' homme of différentes facultés, Brussels 1870