Karl Pearson was one of the most important statesmen, although he had no plans at first to become one. In fact, he studied a bit of everything from pure sciences, like physics, to biology, the study of law and, strange as it sounds, German history.

We owe him many statistical tools that psychologists and other health and social scientists use for virtually everything, such as chi-square or linear correlation.

**In this biography of Karl Pearson we will see the life of this great historical figure** which, with their light and their obscurity, determined the history of all this discipline which considers itself scientific.

Table of Contents

## Brief biography of Karl Pearson

**Karl Pearson was an English historian, lawyer, mathematician, biometer, professor and biographer**. His interests include writing about folklore, learning about philosophy, learning about Germanic culture, following socialist theses, and admiring Karl Marx a lot. But other than all that, what stood out most about Pearson was to be the contributor to the birth of applied statistics and to use it as a fundamental tool in all knowledge considered to be scientific.

There are many Pearson contributions to statistics as we know them today, the most notable being the linear correlation and the χ2 method. Outraged, **she is considered as one of the promoters of the integration of women in scientific and intellectual debates**, Knowledge at the time reserved for the male sex. However, it also has controversial aspects such as being in favor of eugenics influenced by Francis Galton.

### Early childhood and education

**He was born Carl Pearson, with C, on March 27, 1857 in London, England**. His family was originally from Yorkshire, upper middle class and of Puritan lean. His father was a lawyer, which may have influenced Pearson’s life years later when he decided to study law. Young Pearson was educated at home until the age of nine. After that, he began his studies at University College School in London until the age of sixteen.

Due to health problems, he had to temporarily abandon his training at the school, being assigned a private tutor at home. Despite his adversity, he managed to win a scholarship to the prestigious King’s College, Cambridge to study mathematics, which he completed in 1879.

Although coming from a fairly religious environment at 22, Karl **he rejected Christianity and adopted free thought by interpreting it as a kind of faith but not a religious one**. Despite being a free-thinker, he preferred to distinguish his beliefs from those of traditional free-thinkers.

### Visit to Germany

After completing his studies at Cambridge, he traveled to Germany with the intention of studying physics and metaphysics at the University of Heidelberg and also walked to the University of Berlin, where he studied law. But he would devote himself not only to the laws and exact sciences of this period, but also to German medieval history and literature between 1879 and 1880.

In reality, **his eagerness and interest in learning more about the German Middle Ages made him a great acquaintance in this field**So much so that he was later offered a place in German Studies at Cambridge University upon his return to England. One of his works from this period, the result of his passionate interest in Germany, is “The New Werther”, strongly influenced by Johann Wolfgang von Goethe.

It was around this time that, by chance in life, his original name, Carl, changed to Karl at the age of 23. The reason is due to a simple mistake made at the University of Heidelberg. **As the young Karl Pearson was an admirer of Karl Marx, he made this little confusion a sign of identity.**, Thus acquire the name of Karl, with K in German, the rest of his life.

### Tour of England: the men’s and women’s club

In 1881 he began to study law but never practiced law. Later, in 1885, he obtained a post as professor of mathematics at University College where he gained a reputation as a good, albeit somewhat heterodox, professor. During this period, he published “Common sense of exact sciences” and “History of the theory of elasticity”.

Karl Pearson, **in addition to being a great mathematician and scientist, he was interested in the ethics and history of Christianity**, In addition to considering that gender should not be an obstacle to the debate on intellectual issues. This is why in 1885 he founded the Club des Hommes et des Femmes (Club des Hommes et des Femmes), a discussion forum aimed at allowing free discussion between the two kinds.

It was at the Men’s and Women’s Club that he met what would become his wife, Maria Sharpe. With Mary he had three children, Sigrid Loetitia, Helga and Egon, and they lived happily ever after until his death in 1928, marrying Karl Pearson the following year with a colleague from the University of London, Margaret Child.

### Pearson, Galton and Welton

It was in 1890, when Karl Pearson was 33, that a very important event occurred in his life, a life in which he had studied mathematics but had not yet delved into statistics. **He became interested in statistics thanks to Charles Darwin’s cousin, Francis Galton**, Who a year earlier had published his book “Natural Inheritance”.

In 1891 he became professor of geometry at Gresham College, where he made contact with one of the most important zoologists of the 19th century, Walter Frank Raphael Weldon, founder of biometrics. The relationship between Pearson and Weldon was fruitful, which led Karl to acquire knowledge in biometrics and the theory of evolution. Weldon is the one who introduced Pearson to Galton.

Pearson, encouraged by Weldon, took a deeper interest in mathematics describing the processes of inheritance and evolution and, as a result, published a number of papers on analysis. Regression, correlation coefficient plus introduce the test of χ2 (chi or ji squared)

**The relationship between Galton, Weldon and Pearson was magnificent, which led to the founding of Biometrika magazine.**, The anecdote behind this deserves to be commented on. Pearson presented an article to the Royal Society which, although it was done very well, was rejected by Academy biologists who disliked his mathematical analysis. As a result, Weldon suggested that he start his own magazine and, with Galton’s help as well, the three started their own magazine.

### Approach to eugenics and recent years

This is where we start to see one of the darker parts of Pearson due to the influences of Francis Galton who is considered, by many, to be the founder of eugenics. **Galton put Pearson in charge of her eugenics office and she joined her biometrics lab.**, Resulting from the creation of the Department of Applied Statistics at the University College.

It goes without saying that we can neither deny nor reject Pearson’s contributions because they are eugenic. At the time, this current had the support of many scientists and intellectuals, in addition to applying eugenics programs in democratic countries ruled by both the right and the left. However, we must not forget that either **Nazism made great use of eugenic theses and social Darwinism**, Advocates of artificial selection in humans to improve our species.

The admiration for Galton lasted until his death in 1911. His admiration for Galton was such that Pearson went so far as to say that it would be Francis Galton and not Charles Darwin the most wonderful grandson and that he would be the most. famous Erasmus Darwin. It was then that Karl Pearson decided to do a biography of Darwin’s cousin.

The work was published as three volumes which came into existence in 1914, 1924 and 1930. It used as a bibliography a variety of resources, including letters, stories, genealogies, commentaries and photographs of Francis Galton. This work praised Galton’s life, his work and Pearson’s personal legacy. Pearson himself took it out of his pocket so that these books could be printed.

On Galton’s death, Karl Pearson left part of his legacy to the University of London for a research post in eugenics. Complying with the late mentor wishes, Pearson incorporated the Biometric Lab and the Galton Lab. Karl Pearson would remain in this department until his retirement in 1933, although **he continued to work on various projects until his death on April 27, 1936 at the age of 79**.

## Works by Karl Pearson

Karl Pearson’s texts, articles and books are varied. As a great intellectual of his time, with a multifaceted profile touching both the pure sciences and the human sciences, **no wonder his books deal with mathematics, philosophy, history and religion**. Below is a list of some of his works.

- The New Werther (1880)
- The Trinity, a work of passion from the XIX century (1882)
- La Fronica (1887)
- The ethics of free thought (1886)
- The grammar of science (1892)
- On the dissection of asymmetric frequency curves (1894)
- Tilt variation in homogeneous material (1895)
- Regression, inheritance and panmixia (1896)
- On the criterion that a given system of deviations from the probable in the case of a system of correlated variables is such that it can be reasonably assumed to come from a random sampling (1900)
- Tables for statisticians and biometrics (1914)
- Incomplete beta function tables (1934)

#### Bibliographical references:

- Gómez Villegas, MA (2005) Statistical Inference, Madrid: Díaz de Santos.
- Pearson, K. (1900) On the criterion that a given system of deviations from the probable in the case of a system of correlated variables is such that it can be reasonably assumed that it came from a random sampling, Philosophical Magazine 5 th series, 50, 157-175.
- Pearson, K. (1978) The History of Statistics in the 17th and 18th Centuries, edited by ES Pearson. New York: MacMillan.
- Pearson, K. (1895) Contributions to the mathematical theory of evolution, II: tilted variation. Philosophical Transactions of the Royal Society of London, A, 186, 343-414.
- Pearson, K. (1896) Contributions to the Mathematical Theory of Evolution, III: Regression, Inheritance, and Panmixia, Philosophical Transactions of the Royal Society of London, A, 187, 253-318.
- Pearson, K. and Filon, LNG (1898) Contributions to the Mathematical Theory of Evolution, IV: On the possible errors of frequency constants and on the influence of random selection on variation and correlation. Philosophical Transactions of the Royal Society of London, A, 191, 229-311.
- Stigler, SM (1986) The History of Statistics: The Measurement of Uncertainty Before 1900, Cambridge: Belknap Harvard.