Karl Pearson

Karl Pearson FRS (March 27, 1857 – April 27, 1936) established the discipline of mathematical statistics. A sesquicentenary conference was held in London on 23 March 2007, to celebrate the 150th anniversary of his birth. 

In 1911 he founded the world's first university statistics department at University College London. He was a proponent of eugenics, and a protégé and biographer of Sir Francis Galton. He was also a socialist.

Family and biography
Karl was born Carl in Islington, London, England to William Pearson and Fanny Smith. They had three children:
 * Arthur Beilby Pearson, later Pearson-Gee (1855-1896)
 * Carl, later Karl (1857-1936 )
 * Amy (1859-, m. Ernest Hatton, QC, 1880).

William Pearson also reputedly had an illegitimate son, Frederick Mockett (b.1849) . (Recent research at UCL has verified this - see

Pearson's mother came from a family of master mariners who sailed their own ships from Hull; his father read law at Edinburgh and was a successful barrister and Queen's Counsel (QC). KP's father's family came from the North Riding of Yorkshire. The family grave is at Crambe, near York. Its motto, "ERIMUS" means "We shall be", and is also the motto of the Middlesbrough coat-of-arms (see and image of family graves at ).

Other family connections are at Danby, Sleightholmedale, and Rosedale.

Little is known about William Pearson's childhood, although he is said to have been brought up among Quaker relatives in York, and reputedly had an illegitimate son, Frederick Mockett, born 1849. 

The family were dissenters and of Quaker stock; his maternal grandfather was a Unitarian minister. By age 22, Carl had rejected Christianity and adopted ‘Freethought’ as a nonreligious faith that was grounded in science, though he distinguished his views from a ‘Freethinker’ (i.e., a person who forms opinions about religion on the basis of reason without recourse to authority or established beliefs).

'Carl' inadvertently became 'Karl' when the University of Heidelberg changed the spelling at his enrolment in 1879; he used both variants of his name until 1884 when he finally adopted Karl - supposedly also after Karl Marx, whom he certainly met - and eventually he became universally known as ‘KP’.

He was also an accomplished historian and Germanist. He spent much of the 1880's in Berlin, Vienna, Saig bei Lenzkirch, and Brixlegg He wrote on Passion plays, religion, Goethe, Werther, as well as sex-related themes e.g. the Men and Women's Club and Olive Schreiner. For all these, see the book by Theodore Porter.

In 1890 he married Maria Sharpe who was related to the Kenrick, Reid, Rogers and Sharpe families, late 18th century and 19th century non-conformists largely associated with north London. Numbered among their members were such well-known figures as They and their relatives through successive generations were active in many different walks of life, and their interests and friends were very varied. Their papers are at
 * the poet Samuel Rogers (1763-1855)
 * the barrister Sutton Sharpe (1797-1843), whose wide circle of friends included many literary figures
 * the businessman, Egyptologist and philanthropist Samuel Sharpe (1799-1881)
 * the highly respected York non-conformist minister John Kenrick (1788-1877).

Karl and Maria had two daughters, Sigrid Loetitia Pearson (b.1892), and Helga Sharpe Pearson (later Hacker) (b.1898), and one son, Egon Sharpe Pearson (b.1895). Egon was himself later an eminent statistician, and founder of Neyman-Pearson statistics. He succeeded his father as head of the Applied Statistics Department at University College. 

Karl and Maria met at the Men and Women's Club, which was co-founded by KP, and designed to permit free discussion among men and women. Maria died in 1928 and the following year he married Margaret Child, a colleague at University College. The South African author Olive Schreiner was another active member of the Men and Women's Club, which according to was a discussion group which concentrated on "the status of moral judgement, moral change, fact and truth in the face of received opinion about the sexes". (Its) nominal leader ... Karl Pearson, two years younger than Schreiner, was a dynamic character to whom most of the group deferred. Schreiner, however, considered herself much more of his equal, and found his views intellectually stimulating. As the relationship deepened, Schreiner realised that she was looking for more than a platonic friendship. Pearson, however, remained oblivious to her passion. At one point Schreiner signed a letter "Your man-friend OS" in despair at his inability to interact on an emotional level.

Education and early work
Karl Pearson was educated privately at University College School, after which he went to King's College, Cambridge to study mathematics. He then spent part of 1879 and 1880 studying medieval and 16th century German literature at the universities of Berlin and Heidelberg – in fact, he became sufficiently knowledgeable in this field that he was offered a Germanics post at Kings College, Cambridge.

His next career move was to Inner Temple, where he read law until 1881 (although he never practised). After this, he returned to mathematics, deputizing for the mathematics professor at King's College London in 1881 and for the professor at University College London in 1883. In 1884, he was appointed to the Goldsmid Chair of Applied Mathematics and Mechanics at University College London. 1891 saw him also appointed to the professorship of Geometry at Gresham College; here he met Walter Frank Raphael Weldon, a zoologist who had some interesting problems requiring quantitative solutions. The collaboration, in biometry and evolutionary theory, was a fruitful one and lasted until Weldon died in 1906. Weldon introduced Pearson to Charles Darwin's cousin Francis Galton, who was interested in aspects of evolution such as heredity and eugenics. Pearson became Galton's protégé &mdash; his "statistical heir" as some have put it &mdash; at times to the verge of hero worship. After Galton's death in 1911, Pearson embarked on producing his definitive biography&mdash;a three-volume tome of narrative, letters, genealogies, commentaries, and photographs&mdash;published in 1914, 1924, and 1930, with much of Pearson's own financing paying for their print runs. The biography, done "to satisfy myself and without regard to traditional standards, to the needs of publishers or to the tastes of the reading public", triumphed Galton's life, work, and personal heredity. He predicted that Galton, rather than Charles Darwin, would be remembered as the most prodigious grandson of Erasmus Darwin.

When Galton died, he left the residue of his estate to the University of London for a Chair in Eugenics. Pearson was the first holder of this chair, in accordance with Galton's wishes. He formed the Department of Applied Statistics (with financial support from the Drapers' Company), into which he incorporated the Biometric and Galton laboratories. He remained with the department until his retirement in 1933, and continued to work until his death in 1936.

Einstein and Pearson's work
When the 23 year-old Albert Einstein started a study group, the Olympia Academy, with his two younger friends, Maurice Solovine and Conrad Habicht, he suggested that the first book to be read was Pearson's The Grammar of Science. This book covered several themes that were later to become part of the theories of Einstein and other scientists. Pearson asserted that the laws of nature are relative to the perceptive ability of the observer. Irreversibility of natural processes, he claimed, is a purely relative conception. An observer who travels at the exact velocity of light would see an eternal now, or an absence of motion. He speculated that an observer who traveled faster than light would see time reversal, similar to a cinema film being run backwards. Pearson also discussed antimatter, the fourth dimension, and wrinkles in time.

Pearson's relativity was based on idealism, in the sense of ideas or pictures in a mind. "There are many signs," he wrote, "that a sound idealism is surely replacing, as a basis for natural philosophy, the crude materialism of the older physicists." (Preface to 2nd Ed., The Grammar of Science) Further, he stated, "...science is in reality a classification and analysis of the contents of the mind...." "In truth, the field of science is much more consciousness than an external world." (Ibid., Ch. II, § 6) "Law in the scientific sense is thus essentially a product of the human mind and has no meaning apart from man." (Ibid., Ch. III, § 4)

Politics and eugenics
Aside from his professional life, Pearson was active as a prominent freethinker and socialist. He gave lectures on such issues as "the woman's question" (this was the era of the suffragist movement in the UK) and upon Karl Marx. His commitment to socialism and its ideals led him to refuse the offer of being created an OBE (Officer of the Order of the British Empire) in 1920, and also to refuse a Knighthood in 1935. Pearson's views on eugenics, however, would be considered deeply racist today. Pearson openly advocated "war" against "inferior races," and saw this as a logical implication of his scientific work on human measurement: "My view – and I think it may be called the scientific view of a nation," he wrote, "– is that of an organized whole, kept up to a high pitch of internal efficiency by insuring that its numbers are substantially recruited from the better stocks, and kept up to a high pitch of external efficiency by contest, chiefly by way of war with inferior races." He reasoned that, if August Weismann's theory of germ plasm is correct, then the nation is wasting money when it tries to improve people who come from poor stock. Weismann claimed that acquired characteristics could not be inherited. Therefore, training benefits only the trained generation. Their children will not exhibit the learned improvements and, in turn, will need to be improved. "No degenerate and feeble stock will ever be converted into healthy and sound stock by the accumulated effects of education, good laws, and sanitary surroundings. Such means may render the individual members of a stock passable if not strong members of society, but the same process will have to be gone through again and again with their offspring, and this in ever-widening circles, if the stock, owing to the conditions in which society has placed it, is able to increase its numbers." (Introduction, The Grammar of Science).

"History shows me one way, and one way only, in which a high state of civilization has been produced, namely, the struggle of race with race, and the survival of the physically and mentally fitter race. If you want to know whether the lower races of man can evolve a higher type, I fear the only course is to leave them to fight it out among themselves, and even then the struggle for existence between individual and individual, between tribe and tribe, may not be supported by that physical selection due to a particular climate on which probably so much of the Aryan's success depended . . ." (Karl Pearson, National Life from the Standpoint of Science [London, 1905])

Awards from professional bodies
Pearson achieved widespread recognition across a range of disciplines and his membership of, and awards from, various professional bodies reflects this:
 * 4 June 1896: elected FRS: Fellow of the Royal Society
 * 1898: awarded the Darwin Medal
 * 1911: awarded the honorary degree of LLD from the University of St Andrews
 * 1911: awarded a DSc from University of London
 * 1920: offered (and refused) the OBE
 * 1932: awarded the Rudolf Virchow medal by the Berliner Anthropologische Gesellschaft
 * 1935: offered (and refused) a knighthood

He was also elected an Honorary Fellow of King's College Cambridge, the Royal Society of Edinburgh, University College London and the Royal Society of Medicine, and a Member of the Actuaries' Club.

Contributions to statistics
Pearson's work was all-embracing in the wide application and development of mathematical statistics, and encompassed the fields of biology, epidemiology, anthropometry, medicine and social history. In 1901, with Weldon and Galton, he founded the journal Biometrika whose object was the development of statistical theory. He edited this journal until his death. He also founded the journal Annals of Eugenics (now Annals of Human Genetics) in 1925. He published the Drapers' Company Research Memoirs largely to provide a record of the output of the Department of Applied Statistics not published elsewhere.

Pearson's thinking underpins many of the 'classical' statistical methods which are in common use today. Some of his main contributions are:


 * 1) Linear regression and correlation. Pearson was instrumental in the development of this theory. One of his classic data sets (originally collected by Galton) involves the regression of sons' height upon that of their fathers'. Pearson built a 3-dimensional model of this data set (which remains in the care of the Statistical Science Department) to illustrate the ideas. The Pearson product-moment correlation coefficient is named after him, and it was the first important effect size to be introduced into statistics.
 * 2) Classification of distributions. Pearson's work on classifying probability distributions forms the basis for a lot of modern statistical theory; in particular, the exponential family of distributions underlies the theory of generalized linear models.
 * 3) Pearson's chi-square test. A particular kind of chi-square test, a statistical test of significance.

Resume of academic career

 * Third Wrangler in Mathematics Tripos, Cambridge University, 1879
 * studied medieval and sixteenth-century German literature, Berlin and Heidelberg Universities, 1879-1880
 * read law, called to the Bar by Inner Temple, 1881
 * delivered lectures on mathematics, philosophy and German literature at societies and clubs devoted to adult education
 * deputised for the Professor of Mathematics, King's College London, 1881, and for the Professor of Mathematics at University College London, 1883
 * formed the Men and Women's Club, with some others, to discuss equality between the sexes
 * appointed to Goldsmid Chair of Applied Mathematics and Mechanics, University College London, 1884
 * appointed Professor of Geometry, Gresham College, 1891
 * collaborated with Walter Frank Raphael Weldon, Professor of Zoology and Comparative Anatomy, in biometry and evolutionary theory, 1891-1906
 * elected Fellow of the Royal Society, 1896
 * founded journal Biometrika with Weldon and Francis Galton founder of the School of Eugenics at University College London, 1901
 * appointed first Galton Professor of Eugenics, University College London, 1911
 * formed Department of Applied Statistics incorporating the Biometric Laboratory and Galton Laboratory, University College London
 * founded journal Annals of Eugenics, 1925
 * retired, 1933, died at Coldharbour, Surrey, 27 April 1936.

Sources: Obituaries: References: Code
 * Bulloch's Roll; DNB; DSB
 * Obituary Notices of Fellows of the Royal Society 1936-1938 vol 2 pp 73-110, plate, by L N G Filon
 * David C Watt, 'Lionel Penrose, FRS (1898-1972) and Eugenics: Part One' in NR 1998 vol 52 pp 137-151
 * Sahotra Sarkar, 'J B S Haldane and R A Fisher's Draft Life of Karl Pearson' in NR 1995 vol 49 pp 119-124
 * A W F Edwards, 'R A Fisher on Karl Pearson' in NR 1994 vol 48 pp 97-106, plate
 * Meg Weston Smith, 'E A Milne and the Creation of Air Defence: Some Letters From an Unprincipled Brigand, 1916-1919' in NR 1990 vol 44 pp 241-255
 * Bernard Norton and E S Pearson, 'A Note on the Background to, and Refereeing of, R A Fisher's 1918 Paper "On the Correlation Between Relatives on the Supposition of Mendelian Inheritance"' in NR 1976-7 vol 31 pp 151-162
 * A W F Edwards, 'From African exploration to the birth of eugenics. A life of Sir Francis Galton: from African exploration to the birth of eugenics, by N W Gillham' in NR 2002 vol 56 pp 399-400
 * P M Lee, 'Saxony, sexuality, science, socialism and statistics.
 * 'Karl Pearson: The scientific life in a statistical age' by T M Porter' in NR 2005 vol 59 pp 92-93

Publications

 * A first study of the inheritance of vision and of the relative influence of heredity and environment on sight (London, 1909)
 * A preliminary study of extreme alcoholism in adults with A Barrington '(London, 1910)
 * editor of The common sense of the exact sciences (Kegan Paul & Co, London, 1885)
 * On the correlation of fertility with social value: a cooperative study with others (1913)
 * editor of Tables of the incomplete G-function: computed by the staff of the Department of Applied Statistics, University College (London, 1922)
 * Study of the data provided by a baby-clinic in a large manufacturing town (Cambridge, 1922)
 * 'editor of Tracts for computers (London, 1919)
 * 'editor of Tables for statisticians and biometricians (London, 1914)
 * A mathematical theory of random migration (1906)
 * A monograph on albinism in man with E Nettleship and C H Usher '(1911)
 * Charles Darwin, 1809-1882, an appreciation (London, 1923)
 * Darwinism, medical progress and eugenics: ' The Cavendish lecture, 1912, an address to the medical profession  (1912)
 * Enthusiasm of the market place and of the study (1885)
 * Eugenics and public health An address to public health officers (1912)
 * Francis Galton, 1822-1922, a centenary appreciation (London, 1922)
 * Home conditions and eyesight: some recent misinterpretations of the problem of nurture and nature
 * Mathematical contributions to the theory of evolution (1904)
 * Matter and soul (1886)
 * Mendelism and the problem of mental defect (1914)
 * National life from the stand-point of science An address delivered at Newcastle (A & C Black, London, 1901)
 * Nature and nurture, the problem of the future A presidential address (1910)
 * On a practical theory of elliptical and pseudo-elliptical arches, with special reference to the ideal masonry arch with W D Reynolds and W F Stanton ''(1909)
 * On the construction of tables and on interpolation (London, 1920)
 * On the handicapping of the first-born (1914)
 * On the relationship of health to the psychial and physical characters in school children (Cambridge, 1923)
 * On the skull and portraits of George Buchanan (Oliver & Boyd, Edinburgh, London, 1926)
 * Reaction! A criticism of Mr Balfour's attack on rationalism (1895)
 * Side lights on the evolution of man (London, 1921)
 * Social problems, their treatment, past, present, and future A lecture (1912)
 * Studies in national deterioration (1907)
 * Supplement to the memoir (by Ethel M Elderton) entitled: The influence of parental alcoholism on the physique and ability of the offspring A reply to the Cambridge economists (1910)
 * 'editor of Tables of the incomplete beta-function (The Proprietors of Biometrika , London, 1934)
 * The academic aspect of the science of eugenics A lecture delivered to undergraduates (1911)
 * The chances of death and other studies in evolution (E Arnold, London, 1897)
 * The ethic of freethought: a selection of essays and lectures (T Fisher Unwin, London, 1888)
 * The fight against tuberculosis and the death-rate from phthisis (1911)
 * The grammar of science (1892)
 * The groundwork of eugenics (1909)
 * The life, letters and labours of Francis Galton (Cambridge University Press, Cambridge, 1914)
 * The moral basis of socialism (W Reeves, London, 1887)
 * The new university for London: a guide to its history and a criticism of its defects (T F Unwin, London, 1892)
 * The positive creed of freethought: with some remarks on the relation of freethought to socialism (W Reeves, London, 1888)
 * The problem of practical eugenics (1909)
 * The right of the unborn child (Cambridge University Press, London, 1927)
 * The science of man: its needs and its prospects (London, 1920)
 * The skull and portraits of Henry Stewart, Lord Darnley, and their bearing on the tragedy of Mary, Queen of Scots (1928)
 * editor of The treasury of human inheritance (Dulau & Co, London, 1909)
 * Tuberculosis, heredity and environment (1912)
 * A study of the long bones of the English skeleton (London, 1919)
 * On the sesamoids of the knee-joint (Cambridge, 1922)
 * A second study of the influence of parental alcoholism on the physique and ability of the offspring (1910)
 * editor of A second study of the statistics of pulmonary tuberculosis: marital infection (London, 1908)
 * editor of A history of the theory of elasticity and of the strength of materials from Galilei to the present time (University Press, Cambridge, 1886-1893)
 * The Trinity: a nineteenth century passion-play (E Johnson, Cambridge, 1882)
 * A statistical study of oral temperatures in school children, with special reference to parental, environmental, and class differences with M H Williams and Julia Bell (1914)
 * On the torsion resulting from flexure in prisms with cross-sections of uni-axial symmetry only with A W Young, M A Ethel and M Elderton(1918).


 * The New Werther (1880)
 * The Trinity, A Nineteenth Century Passion Play (1882)
 * Die Fronica (1887)
 * The Ethic of Freethought (1886)
 * The Grammar of Science (1892), Dover Publications 2004 edition, ISBN 0-486-49581-7
 * On the dissection of asymmetrical frequency curves (1894)
 * Skew variation in homogeneous material (1895)
 * Regression, heredity and panmixia (1896)
 * On the criterion that a given system of deviations from the probable in the case of a correlated system of variables is such that it can be reasonably supposed to hove arisen from random sampling (1900)
 * Tables for Statisticians and Biometricians ((1914))
 * Tables of Incomplete Beta Function (1934)
 * The life, letters and labours of Francis Galton (3 vol.: 1914, 1924, 1930). Available in full at http://galton.org