Maximilien Ringelmann (10 December 1861, Paris – 2 May 1931, Paris) was a French professor of agricultural engineering who discovered the "Ringelmann effect", viz, that when working in groups, individuals slacken.
After graduating from the public schools of Paris, Ringelmann studied at the Institute National Agronomique (National Institute of Agronomy), where he was an outstanding student. He also attended Hervé Mangon’s evening course in rural engineering at the Conservatoire National des Arts et Métiers (National Conservatory of Arts and Crafts). (Charles-François Hervé Mangon (1821–1888) had been trained as a civil engineer, but his interest shifted to agriculture, where he studied irrigation, drainage, fertilizers, etc.)  Ringelmann also attended courses at the École Nationale des Ponts et Chaussées (National School of Bridges and Roads), a civil engineering school. He became an agronomic engineer in 1880. Starting in 1881, he tutored the course in rural engineering at the École Nationale d’Agriculture (National School of Agriculture) in Grand Jouan, Nozay, France. By 1883, he was contributing a weekly column to the Journal d’Agriculture Pratique (Journal of Practical Agriculture).
Up to that time, the development of agricultural machinery had been done largely by amateurs. Eugène Tisserand, a director at the Ministry of Agriculture, wanted to apply a scientific approach to the development and evaluation of farm machinery. He therefore requested that Ringelmann draft plans for a facility for testing agricultural machinery, which after many vicissitudes opened in 1888. The facility was established on Jenner Street in Paris and Ringelmann was named its director. He adapted industrial instruments where possible, but he also designed and had built instruments such as traction dynamometers, rotational dynamometers, profilographs, etc. He aimed to determine the efficiency of agricultural machinery, its economics, the quality of the work performed, etc. His wide-ranging interests soon led him to extend his research to include all branches of rural engineering: construction, drainage, irrigation, electrification, hydraulics.
In 1887, Ringelmann was elected to the Académie d’Agriculture, and in the same year, he became professor of mechanics and rural engineering at the École Nationale d’Agriculture in Grignon. In 1897, he succeeded his former professor Hervé Mangon as professor of rural engineering at the Institute National Agronomique. He became in 1902 professor of colonial rural engineering at the École Nationale Supérieure d’Agriculture Coloniale in Nogent-sur-Marne.
In 1897 he developed a simple set of grids for measuring the density of smoke, the Ringelmann scale. These grids are still used today. During 1900-1905, he wrote a monumental, four-volume study Essai sur l’Histoire du Génie Rural (Essay on the History of Rural Engineering), which traced the progress of rural engineering from pre-history to the modern age.
Ringelmann is especially notable for discovering the Ringelmann effect in 1913, also known as "social loafing". Specifically, Ringelmann had his students, individually and in groups, pull on a rope. He noticed that the effort exerted by a group was less than the sum of the efforts exerted by the students acting individually.
Original text : Pour l’emploi de l’homme, comme d’allieurs des animaux de trait, le meilleure utilisation est réalisée quand le moteur travaille seul : dès qu’on accouple deux ou plusieurs moteurs sur la même résistance, le travail utilisé de chacun d’eux, avec la même fatigue, diminue par suite du manque de simultanéité de leurs efforts …
Translation : When employing men, or draught animals, better use is achieved when the source of motive power works alone: as soon as one couples two or several such sources to the same load, the work performed by each of them, at the same level of fatigue, decreases as a result of the lack of simultaneity of their efforts …
This finding is one of the earliest discoveries in the history of Social Psychology, allowing Ringelmann to be described by some as a founder of Social Psychology.
Ringelmann traveled within Europe and to North America in order to observe those areas where mechanization of agriculture had progressed rapidly. He also traveled to France’s colonies—particularly in North Africa—in order to study the special problems posed by the local climate and by the pre-industrial technology that was used by the native farmers.
His expertise in agricultural engineering was sought by inventors, industrialists and farmers.
He died in Paris on 2 May 1931.
Ringelmann's publications include:
- Ringelmann, Maximilien, Les Machines Agricoles (Paris: Hachette, 1888–1898), 2 vol.s.
- Ringelmann, Maximilien, Les Travaux et Machines pour mise en Culture des Terres (Paris: Librarie agricole de la Maison rustique, 1902). (Reviewed in Revue des cultures coloniales, vol. 11, no. 110, pages 217-218 (October 5, 1902).)
- Ringelmann, Maximilien, Génie Rural Appliqué aux Colonies [Rural engineering applied in the colonies] (Paris: Augustin Challamel, 1908).
- Ringelmann, Maximilien, Recherches sur les moteurs animés. Travail de l'homme. Annales de l'Institut national agronomique. Tome VII. 1913. p. 1-40 (main publication about the so-called Rigelmann effect)
- Ringelmann, Maximilien, Puits Sondages et Sources [Well drilling and wellheads] (Paris, 1930).
- Kravitz, David A.; Martin, Barbara (1986). "Ringelmann rediscovered: The original article" (PDF). Journal of Personality and Social Psychology. 50 (5): 936–941.
- Simon, Bernard "Max Ringelmann (1861-1931) et la recherche en machinisme agricole" [Max Ringelmann (1861–1931) and research into the mechanization of agriculture] in Cahiers d'Histoire et de Philosophie des Sciences, No. 46: Histoire de la méchanique appliquée. Enseignement, recherche et pratiques mécaniciennes en France après 1880, Claudine Fontanon, ed. (Paris: ENS Editions, 1998), pages 47–55. (ISBN 2-902126-50-6) Available (in part) on-line at: Google Books.
- Wery, Georges (August 1931). "Nécrologie: Max Ringelmann" [Obituary: Max Ringelmann]. L'Agriculture pratique des pays chauds [Practical agriculture in hot countries]. 2nd series (in French). 14: 621–624.
- Uekoetter, F. (2005). "The strange career of the Ringelmann smoke chart". Environmental Monitoring and Assessment. 106 (1–3): 11–26. doi:10.1007/s10661-005-0756-z. PMID 16001709.
- Dates and places of Ringelmann's birth and death from: B. Simon (1998), page 55.
- Gaston Tissander, Obituary: “Hervé Mangon”, La Nature, vol. 782, pages 401-403 (May 26, 1888).
- Grand Jouan is located roughly midway between the cities of Rennes and Nantes, France.
- B. Simon (1998), page 48.
- B. Simon (1998), page 55.
- Ringelmann Smoke Chart. U.S. Department of the Interior, Bureau of Mines, Information Circular 8333, 1967 May:1-12
- Ringelmann, M. (1913) "Recherches sur les moteurs animés: Travail de l'homme" [Research on animate sources of power: The work of man], Annales de l'Institut National Agronomique, 2nd series, vol. 12, pages 1-40.
- Social Loafing
- Ringelmann (1913), page 9.
- B. Simon (1998), page 49.