André-Michel Guerry (; December 24, 1802 – April 9, 1866) was a French lawyer and amateur statistician. Together with

Adolphe Quetelet Lambert Adolphe Jacques Quetelet FRSF or FRSE (; 22 February 1796 – 17 February 1874) was a Belgian astronomer, mathematician, statistician and sociologist who founded and directed the Brussels Observatory and was influential in introduc ...

he may be regarded as the founder of

moral statistics Moral statistics most narrowly refers to numerical data generally considered to be indicative of social pathology in groups of people. Examples include statistics on crimes (against persons and property), illiteracy, suicide, illegitimacy, abortion ...

which led to the development of

criminology Criminology (from Latin , "accusation", and Ancient Greek , ''-logia'', from λόγος ''logos'' meaning: "word, reason") is the study of crime and deviant behaviour. Criminology is an interdisciplinary field in both the behavioural and so ...

sociology Sociology is a social science that focuses on society, human social behavior, patterns of Interpersonal ties, social relationships, social interaction, and aspects of culture associated with everyday life. It uses various methods of Empirical ...

and ultimately, modern

social science Social science is one of the branches of science, devoted to the study of societies and the relationships among individuals within those societies. The term was formerly used to refer to the field of sociology, the original "science of soc ...

Early life and education

Guerry was born in

Tours Tours ( , ) is one of the largest cities in the region of Centre-Val de Loire, France. It is the Prefectures in France, prefecture of the Departments of France, department of Indre-et-Loire. The Communes of France, commune of Tours had 136,463 ...

, Indre-et-Loire, the only child of Michel Guerry, a building contractor, whose family had a long history as innkeepers, merchants, farmers and trades-people. About 1817-1820 he studied at the Imperial College of Tours (now the Lyceum Descartes, founded in 1807) and subsequently studied law at the

University of Poitiers The University of Poitiers (UP; french: Université de Poitiers) is a public university located in Poitiers, France. It is a member of the Coimbra Group. It is multidisciplinary and contributes to making Poitiers the city with the highest studen ...

. About 18241825 he moved to Paris and was admitted to the bar as a royal advocate. Shortly after, he was employed by the Ministry of Justice. Guerry worked with the data on crime statistics in France collected as part of the ''General office for administration of criminal justice'' in France, the first centralized national system of crime reporting. Guerry was so fascinated with these data, and the possibility to discover empirical regularities and laws that might govern them, that he gave up the active practice of law to devote the rest of his life to study crime and its relation to other moral variables.

Moral statistics and criminology

Guerry's first work on what would come to be called ''

'' was a large, one page sheet containing three shaded maps of France, prepared together with the Venetian geographer,

Adriano Balbi Adriano Balbi (April 25, 1782 – March 14, 1848), Italian geographer, was born at Venice. The publication of his ''Prospetto politico-geografico dello stato attuale del globo'' (Venice, 1808) obtained his election to the chair of professor of geog ...

in 1829. These showed the departments of France, shaded according to crimes against persons, crimes against property, and school instruction. Such statistical maps, now called

choropleth A choropleth map () is a type of statistical thematic map that uses pseudocolor, i.e., color corresponding with an aggregate summary of a geographic characteristic within spatial enumeration units, such as population density or per-capita inc ...

maps had just been invented in 1826 by Baron

Charles Dupin Baron Pierre Charles François Dupin (6 October 1784, Varzy, Nièvre – 18 January 1873, Paris, France) was a French Catholic mathematician, engineer, economist and politician, particularly known for work in the field of mathematics, where the ...

. Guerry is best known for his ''Essay on moral statistics of France,'' presented to the French Academy of Sciences on July 2, 1832, and published in 1833 after it was awarded the

Prix Montyon The Montyon Prize (french: Prix Montyon) is a series of prizes awarded annually by the French Academy of Sciences and the Académie française. They are endowed by the French benefactor Baron de Montyon. History Prior to the start of the French ...

in statistics. His presentation, in tables and

thematic map A thematic map is a type of map that portrays the geographic pattern of a particular subject matter (theme) in a geographic area. This usually involves the use of map symbols to visualize selected properties of geographic features that are not ...

s, showed that rates of crime and suicide remained remarkably stable over time, when broken down by age, sex, region of France and even season of the year. Yet, these numbers also varied systematically across departments of France. This regularity of ''social numbers'' created the possibility to conceive that human actions could be described by social laws, just as inanimate actions were governed by physical laws. Throughout his career, Guerry was particularly interested in uncovering the relation between social and moral variables. How are personal crime and property related to each other, and to suicide, donations to the poor, illegitimate births, wealth, and so forth? How do different types of crimes vary with age of the accused? Statistical methods (

correlation In statistics, correlation or dependence is any statistical relationship, whether causal or not, between two random variables or bivariate data. Although in the broadest sense, "correlation" may indicate any type of association, in statistics ...

and regression) were still in their infancy, so Guerry relied on graphic comparisons of maps and semi-graphic tables. Shown below are three of the six thematic maps that Guerry included in his ''Essay.''

Suicide

In addition to a map of France showing rates of suicide by department, Guerry collected all the

suicide note A suicide note or death note is a message left behind by a person who dies or intends to die by suicide. A study examining Japanese suicide notes estimated that 25–30% of suicides are accompanied by a note. However, incidence rates may depe ...

s found by the police in Paris over a four-year period. He classified these by the apparent motive expressed for taking one's life, perhaps the first

content analysis Content analysis is the study of documents and communication artifacts, which might be texts of various formats, pictures, audio or video. Social scientists use content analysis to examine patterns in communication in a replicable and systematic ...

in the social sciences.

Ordonnateur statistique

Around 1851, Guerry invented the

Ordonnateur Statistique An ''ordonnateur'' or ''commissaire-ordonnateur'' in the French colonial era was responsible for fiscal matters in a colony, as opposed to the governor, who was responsible for the military. The relationship between the two heads was often tense. ...

, probably the first mechanical device designed to aid in statistical calculations and the assessment of relationships among moral variables.Larousse, P. (1872) Grand dictionnaire universel du XIX siecle, Paris. Vol. 8, Entry for A-M Guerry This device is now known to have been used for sorting one target variable (e.g., crimes of different types) in relation to other possibly explanatory variables (e.g., population density).

Polar area diagram

In 1829, Guerry invented a new graphic form, the

polar area diagram A pie chart (or a circle chart) is a circular statistical graphic, which is divided into slices to illustrate numerical proportion. In a pie chart, the arc length of each slice (and consequently its central angle and area) is proportional t ...

to show variations in weather and other phenomena over calendar cycles. This variation of the

pie chart A pie chart (or a circle chart) is a circular Statistical graphics, statistical graphic, which is divided into slices to illustrate numerical proportion. In a pie chart, the arc length of each slice (and consequently its central angle and are ...

uses equi-angular sectors of differing radii, in contrast to the pie chart that uses sectors with varying angle, but equal radii. The polar area diagram is often mistakenly credited to

Florence Nightingale Florence Nightingale (; 12 May 1820 – 13 August 1910) was an English Reform movement, social reformer, statistician and the founder of modern nursing. Nightingale came to prominence while serving as a manager and trainer of nurses during t ...

, who used it to great effect to illustrate needless mortality in the

Crimean War The Crimean War, , was fought from October 1853 to February 1856 between Russia and an ultimately victorious alliance of the Ottoman Empire, France, the United Kingdom and Piedmont-Sardinia. Geopolitical causes of the war included the de ...

due to unsanitary medical conditions. Nightingale most probably got the idea from

William Farr William Farr CB (30 November 1807 – 14 April 1883) was a British epidemiologist, regarded as one of the founders of medical statistics. Early life William Farr was born in Kenley, Shropshire, to poor parents. He was effectively adopted by ...

, who in turn was acquainted with Guerry's work.

Other activities

Guerry also resided in

Beaumont-sur-Dême Beaumont-sur-Dême () is a commune in the Sarthe department in the region of Pays de la Loire in north-western France. See also *Communes of the Sarthe department The following is a list of the 354 communes of the Sarthe department of France. ...

, where he was mayor of the village from 1846 to 1855.

Major works

* Balbi, Adriano, and André-Michel Guerry. 1829. ''Statistique comparée de l'état de l'instruction et du nombre des crimes dans les divers arrondissements des Académies et des Cours Royales de France.'' Paris
Image
* Guerry, André-Michel. 1829. ''Mémoire sur les variations méterologiques comparées aux phénomènes physiologiques''. Annales d'Hygiène Publique et de Médecine Légal 1:228. * Guerry, André-Michel. 1832. ''Statistique comparée de l’état de l’instruction et du nombre des crimes''. Paris: Evera
Gallica
* Guerry, André-Michel. 1832. ''Motifs des crimes capitaux, d’apres les comptes de l’administration de la justice criminelle''. Annales d’Hygiène Publique et de Médecine Légale, 8, 335–346. * Guerry, André-Michel. 1833. ''Essai sur la statistique morale de la France''. Paris: Crochard
Gallica
* Guerry, André-Michel. 1864. ''Statistique morale de l'Angleterre comparée avec la statistique morale de la France, d'après les comptes de l'administration de la justice criminelle en Angleterre et en France, etc.'' Paris: J.-B. Baillière et fils.

References

External links

Milestones project

A.-M. Guerry's ''Moral Statistics of France''
*Friendly M. (2007) A.-M. Guerry's Moral Statistics of France: Challenges for Multivariable Spatial Analysis, ''Statistical Science'', 22 (3), 368–399
Project Euclid
*Friendly, M. & de Saint Agathe, N. (2012) André-Michel Guerry's Ordonnateur Statistique: The First Statistical Calculator?, ''The American Statistician'', v. 66(3), 195–200

*Friendly, M. (2022). The Life and Work of André-Michel Guerry, Revisited. in press, ''Sociological Spectrum'
pre-print
{{DEFAULTSORT:Guerry, Andre Michel 1802 births 1866 deaths 19th-century French lawyers French statisticians Crime mapping University of Poitiers alumni