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Celebration day: 400th birthday of John Graunt, citizen scientist of London

Publication: Environmental Health Review
13 November 2020
Born in 1620, John Graunt is a giant in the history of science. With a single publication describing an analysis of the London Bills of Mortality, he laid the foundation for statistics, epidemiology, and demography alike. His work is also interesting from the perspectives of citizen science, open science, and reproducible research, and specifically from the perspective of environmental epidemiology.

John Graunt’s Observations

April 24, 2020 marked the 400th birthday of John Graunt who has been dubbed the Father of Statistics, and the First Epidemiologist and Demographer by no less than Karl Pearson (Pearson, 1978) and Kenneth Rothman (Rothman, 1996), respectively. In 1662, John Graunt published a slim book of 97 pages (Graunt, 1662), with the title “Natural and Political OBSERVATIONS Mentioned in the following Index, and Made upon the Bills of Mortality,” commonly called the “Observations” (see Figure 1). A reprint of the Observations appeared in Benjamin and Graunt (1964). Therein, Graunt presents an analysis of the London Bills of Mortality. The book caught the attention of King Charles II, on whose recommendation John Graunt was granted membership in the newly established Royal Society, which was no small feat for a commoner.
Figure 1: 
Figure 1: Title page of John Graunt’s Observations. (Credit: Wellcome Collection. Attribution 4.0 International (CC BY 4.0))

The Bills of Mortality

The Bills of Mortality are an early example of a health surveillance system. The Church of England was mandated to assemble weekly mortality data for each parish in and around the City of London, including the number of and reasons for deaths. “Searchers” were employed by the church to report all deaths in a parish and inquire about the cause of death from family and physicians. Of special interest was mortality due to the plague. Repeated plague epidemics had caused political and economic disruptions for centuries (Morabia, 2013). The earliest known Bills of Mortality for London are from 1532 (Berry, 1995). Graunt accessed as many bills as available to him and then arranged data from a population perspective (Morabia, 2013). Using “population thinking” he discovered that the frequency of chronic diseases was relatively stable, whereas contagious diseases were varying by season and place or parish. Among others, he concluded, “the country is more healthful, than the city.” This was the biggest advancement since Hippocrates around 400 BC suggested environmental factors to advance disease, and it was the beginning of vital statistics and epidemiology, or concisely speaking: the origin of statistical epidemiology.
With respect to demography, Graunt reported on the human sex ratio as well as the population size in London. He showed that the male to female sex ratio in London was 14 to 13, and thus argued against polygamy. Graunt estimated the population size of London in 1661 to be about 384,000 inhabitants using five different approaches, including an estimate based on the first life-table (Hald, 1990).

Biographical Notes About John Graunt

Glass et al. (1963) and Sutherland (1963) reported the few details that are known about John Graunt’s life. Briefly, he was born in London on 24 April 1620 as the eldest child of Henry and Mary Graunt. John Graunt became an apprentice in his father’s business as “Haberdasher of small wares,” and in 1641 he became a Freeman of the Draper’s Company. In 1658, Graunt became a Livery of the Company. He was a well-respected citizen of London, who served as Captain and Major of a trained military band and was eventually elected to City Council. His membership in the Royal Society may be considered the peak moment of his life. He was active in the Royal Society as Council member from 1664 to 1666. The Great Fire of London in 1666 burnt down his house and business. He died in London on 18 April 1674 of jaundice and liver disease, leaving his wife Mary and their children behind. There is no known portrait of Graunt (Murray et al. 2019).


John Graunt was a shopkeeper, not a nobleman. He was an autodidact lacking academic education; nonetheless, he was confident in his accounting skills or “Shop Arithmetique.” He was driven by curiosity and the will to “finding some Truths” regarding new uses of the Bills of Mortality as he was interested to bring “benefit” to the World. In the pursuit, he developed new concepts for data analysis based on population thinking.
Morabia (2013) estimated that Graunt must have assembled data from more than 2,500 sheets. He made use of data from the bills he had bought by subscription, but must also have consulted the original files held at the Hall of Company of Parish Clerks, because the public bills only reported on 63 diseases as the cause of death, whereas Graunt included in his publication the full set of 81 causes of death (Hald, 1990). This was an enormous undertaking. Today, we would call this an application of big data analytics. The data were Voluminous. They were also Volatile and later editions of the Observations were extended by new bills. The data were reports on a Variety of aspects of life: christenings, burials, and death due to a Variety of diseases. These are the 3 Vs of big data. Graunt discussed an additional V: the Veracity or trustworthiness of the data (Rothman, 1996). He found evidence for misclassification of cause of death and undercounting of plague deaths by “a quarter-part.” While he blamed the Searchers for taking bribes and producing untruthful data, he found an adjustment factor and also argued “it matters not to our purposes.” He seemed to understand the concept of nondifferential misclassification bias.
From a current perspective John Graunt was an amateur rather than a professional scientist. His scientific endeavor would thus be best described as citizen science. Although a generally accepted definition of citizen science is lacking (Auerbach et al. 2019; Heigl et al., 2019), its attributes include active involvement of the public in scientific research (Irwin 2018). Furthermore, citizen science is based on the virtues of being research to the benefit of the public, being open science, and being reproducible. Obviously, Graunt subscribed to these virtues: he presented excerpts of the raw data as well as aggregates he had used in the analysis. Furthermore, he described his methods and showed how the same result comes from variations of the data analysis, thus demonstrating replicability and not just reproducibility of his findings. And finally, Graunt asked the reader to correct his findings should there be any mistakes.

Future Directions

John Graunt has been called the founder of statistics and epidemiology and was characterized as a “serious amateur scientist” in London (Choi, 2012). In conclusion, these descriptions should be revised and elevated to “John Graunt Citizen Scientist of London, first statistical epidemiologist and proponent of Open Science.”


Auerbach J., Barthelmess E. L., Cavalier D., Cooper C. B., Fenyk H., Haklay M., et al. 2019 The problem with delineating narrow criteria for citizen science Proc Natl Acad Sci USA 116 31 15336 -15337
Benjamin B. and Graunt J. 1964 John Graunt’s “observations”: Foreword J Inst Actuar 90 1 1 -61
Berry H. 1995 A London Plague Bill for 1592, Crich, and Goodwyffe Hurde Engl Lit Renaiss 25 1 3 -25
Choi B. C. 2012 The past, present, and future of public health surveillance Scientifica 875253
Glass D., Ogborn M., and Sutherland I. 1963 John Graunt and his natural and political observations [and discussion]. Proc Roy Soc London Series B Biol Sci 159 974 2 -37
Graunt, J. 1662. Natural and political observations mentioned in a following Index, and made upon the Bills of Mortality. Available at: Early English Books Online: [Accessed 16 October 2020.]
Hald, A. 1990. Chapter 7: John Graunt and the observations made upon the bills of mortality, 1662. In History of probability and statistics and their applications before 1750. Hald, A. (Ed.), pp. 81–105. New York, USA: Wiley.
Heigl F., Kieslinger B., Paul K. T., Uhlik J., and Dörler D. 2019 Opinion: Toward an international definition of citizen science Proc Natl Acad Sci USA 116 17 8089 -8092
Irwin A. 2018 Citizen science comes of age Nature 562 480 -482
Morabia A. 2013 Epidemiology’s 350th anniversary: 1662–2012 Epidemiology 24 2 179 -183
Murray E., Farland L., Caniglia E., Dorans K., DuPre N., Hughes K., Kim I., Pernar C., Tanz L., and Zack R. 2019 Is this a portrait of John Graunt? An art history mystery Am J Epidemiol 2020 Oct 1 189 10 1204 -1207
Pearson, E. S. 1978. The history of statistics in the 17th and 18th centuries: Against the changing background of intellectual, scientific, and religious thought, lectures by Karl Pearson Given at University College London during the academic sessions 1921–1933. London, UK: Charles Griffin & Company Ltd.
Rothman K. 1996 Lessons from John Graunt Lancet 347 37 -39
Sutherland I. 1963 John Graunt: A tercentenary tribute J Roy Stat Soc Series A 126 4 537 -556

Information & Authors


Published In

cover image Environmental Health Review
Environmental Health Review
Volume 63Number 3November 2020
Pages: 67 - 69


Version of record online: 13 November 2020



Department of Population Medicine, University of Guelph, 50 Stone Road E., Guelph, ON, Canada, N1G 2W1 Canada
Kurtis Sobkowich
Department of Population Medicine, University of Guelph, 50 Stone Road E., Guelph, ON, Canada, N1G 2W1 Canada
Theresa M. Bernardo
Department of Population Medicine, University of Guelph, 50 Stone Road E., Guelph, ON, Canada, N1G 2W1 Canada

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