Heritage: Former UCS schoolboy and statistician Karl Pearson was revered by Einstein

Statistician Karl Pearson. Picture: UCL Archive

Statistician Karl Pearson. Picture: UCL Archive - Credit: UCL Archive

In the latest of our series commemorating people honoured with blue plaques, Adam Sonin explores the life of statistician, eugenicist and former UCS schoolboy Karl Pearson, one of the founding fathers of modern mathematical statistics.

A blue plaque commemorating Karl Pearson. Picture: Simon Harriyott

A blue plaque commemorating Karl Pearson. Picture: Simon Harriyott - Credit: Simon Harriyott

He was a man of many intellectual abilities. Not only did Karl Pearson graduate from Cambridge as third wrangler (placed third in the mathematical tripos) but he was also sufficiently erudite in German language and literature to be offered a Cambridge lectureship in the subject.

He turned down the lectureship to study law, but returned to mathematics in 1884 as a professor at University College London. When a fellow professor, the eminent zoologist Walter Weldon, turned to him for assistance with statistical problems, he devoted his intellectual energies to the subject.

Pearson published more than 30 pioneering and important papers on statistics between 1893 and 1901 and is credited with establishing the modern discipline of mathematical statistics. He introduced a number of methods, including the chi-square test and was instrumental in the development of correlation theory.

Weldon introduced Pearson to the Victorian polymath Sir Francis Galton, a cousin of Charles Darwin. When Galton died in 1911 and left money for the creation of a chair in the now controversial subject of eugenics, Pearson was its first holder.

Fellow socialist George Bernard Shaw wrote: “When I get my hand in sufficiently I think I will write ‘Karl Pearson, a Tragedy’. Can anything be done to rescue you from your professorship?”

A lifelong socialist, Pearson refused all non-academic honours, including the knighthood offered to him in the year before his death in 1936 and simply referred to himself as KP.

Most Read

He was born at 14 Albion Road, Holloway Road, Islington, on March 27 1857. His parents were Quakers of Yorkshire descent and his father William was a stern-natured and career-minded barrister of the Inner Temple.

Pearson’s relationship with his father was strained and in 1907, on William’s death, he wrote: “An iron man with boundless working power, who never asked a favour in his life, and never really got on because he forgot to respect any man’s prejudices, and never knew when he was beaten. I learnt many things from him, and know that I owe much to him, physically and mentally. But we were too alike to be wholly sympathetic. He thought my science folly and I thought his law narrowing – the view of both of us being due to an inherited want of perspective in the stock!”

Between 1863 and 1866, Pearson and his older brother Arthur boarded at William Penn’s small school in Harrow. Then, for a short time in 1866, they received tuition from Penn at their family home, which allowed them to be closer to their mother who provided the emotional nourishment denied by their father.

In the autumn of 1866, Pearson was sent to University College School (UCS) in Hampstead. Photographs reveal he played cricket during his time there. In one picture, he is seen in smart attire, resting against a writing desk, clutching a cricket bat in one hand and holding a straw boater hat in the other. He left the school in 1873 and went to Cambridge. In April 1875, he obtained a scholarship at King’s College, Cambridge, placing second on the list.

While at King’s, Pearson gained notoriety when he rebelled against the required divinity lectures and chapel attendance. The campaign resulted in the abolition of this system in March 1878. Although his rebellion was directed more against the requirements than against religion itself (after being released from compulsory chapel he shocked the tutors and deans by continuing to attend whenever the spirit moved him), it was nevertheless indicative of his early loss of Christian faith.

As a result of his Quaker upbringing, he was discouraged from dogmatic belief in the Biblical story of creation and, by the time he was in his early 20s, he had absorbed Darwinism and taken a special interest in Spinozism as an intellectual religion. Thereafter, he identified himself as a free thinker and an agnostic.

Pearson graduated with a BA in 1879 and was awarded a King’s College fellowship giving him financial independence for several years and an opportunity to travel to Heidelberg and Berlin. He spent about 18 months in Germany, studying mathematics, physics and philosophy.

His first two publications (both anonymous) arose from his wide reading in philosophy, religious thought and German history. The New Werther (1880) was a work of fiction written in the form of letters from a young man wandering in Germany “seeking a creed of life”, and The Trinity: A Nineteenth Century Passion Play (1882), which “attacked orthodox Christianity from the point of view of modern science and culture”.

In The New Werther, he wrote: “I rush from science to philosophy, and from philosophy to our old friends the poets; and then, over-wearied by too much idealism, I fancy I become practical in returning to science. Have you ever attempted to conceive all there is in the world worth knowing – that not one subject in the universe is unworthy of study? ... Mankind seems on the verge of a new and glorious discovery. What Newton did to simplify the planetary motions must now be done to unite in one whole the various isolated theories of mathematical physics.”

His father always intended that his sons should follow him into law and, on Pearson’s return to London in November 1880, he entered Lincoln’s Inn to prepare for a legal career.

It is believed that he first began associating with Bernard Shaw in 1880. Pearson noted: “Coming to London, I read in chambers in Lincoln’s Inn, drew up bills of sale, and was called to the bar, but varied legal studies by lecturing on heat at Barnes, on Martin Luther at Hampstead, and on Lassalle and Marx on Sundays at revolutionary clubs around Soho.”

He was called to the bar at the end of 1881 but only practised briefly. Apparently, the civil engineer Sir Alexander Kennedy convinced him to abandon law and return to mathematics.

He worked as a substitute lecturer in mathematics at King’s and University Colleges in London and published various works. In June 1884, he received his first academic appointment as Goldsmid professor of applied mathematics and mechanics at University College.

On June 30, 1890, he married Maria Sharpe, with whom he had a son and two daughters.

His major accomplishment of this early period was his Grammar of Science (1892) – a book which would become a favourite of many scientists, including the young Albert Einstein.

Pearson was famous for the series of lectures he gave as holder of the Gresham College chair of geometry from 1891 to 1893. The lectures, The Geometry of Statistics and The Laws of Chance, drew audiences of as many as 300 students. He used dice, roulette results and 10,000 pennies scattered on the floor to demonstrate the laws of probability and represent his earliest forays into statistical theory.

In an autobiographical sketch written in 1934, he accounted for his scientific achievements and success in founding a new academic discipline in terms of two purportedly inherited qualities – “a capacity for hard work and a capacity for roving into other people’s preserves”.

He was an energetic teacher and researcher, always extremely generous to his co-workers, but reportedly prone to angry outbursts. He engaged in intellectual disputes which often descended into personal bitterness – even with some of his former pupils and friends.

His house, at 7 Well Road, in Hampstead, where he lived from 1892 up until his death, is one of a procession of semi-detached red-brick pairs built around 1880. The house was the birthplace of his son Egon (1895–1980), also an eminent statistician.