罗纳德·费希尔Ronald Fisher

罗纳德·费希尔的父母是Katie 托马斯·利特尔·希思，一位律师的女儿，以及George Fisher，来自Robinson和费希尔，一家位于伦敦圣詹姆斯国王街的拍卖行。Katie和George有七个孩子，四男三女。在1876年Geoffrey和1877年Evelyn出生后，他们给次年出生的第三个孩子取名为Alan。他很早就夭折了，Katie因为迷信，决定从那时起他们所有的孩子的名字中都要有一个“y”。费希尔 Aylmer 费希尔是双胞胎中的第二个，但年长的双胞胎是死产的。

1904年，费希尔进入哈罗公学，但这对这个十四岁的男孩来说是一段艰难的时期，因为他的母亲在那一年死于急性腹膜炎。尽管如此，他在哈罗表现出色，于1906年在面向全校的数学论文竞赛中赢得了Neeld奖章。费希尔获得了剑桥大学凯厄斯和冈维尔学院的80英镑奖学金，由于他的父亲失去了财产，这笔奖学金对于资助他的学业是必要的。1909年10月，他在剑桥大学注册入学。

尽管他在剑桥学习数学和天文学，但他也对生物学感兴趣。在大学二年级时，他开始向大学里的资深成员咨询成立剑桥大学优生学会的可能性。他以优异成绩毕业于1912年的数学荣誉学位考试。然而，他的导师认为他本可以做得更好，写道3：-

……如果他循规蹈矩，本可以成为一流数学家，但他不会。

获得沃拉斯顿奖学金后，他在剑桥继续跟随斯特拉顿研究误差理论，阅读乔治·比德尔·艾里的手册Theory of Errors。正是费希尔对误差理论的兴趣最终引导他研究统计学问题。

离开剑桥后，费希尔没有经济支持手段，在加拿大一个农场工作了几个月。他回到伦敦，在Mercantile and General Investment Company担任统计员。1914年战争爆发时，他热情地试图参军，此前在剑桥时已在军官训练团接受过训练。他的体检显示除视力外各方面均为A1，视力被评为C5，因此他被拒绝。他成为数学和物理教师，1915年至1919年间在拉格比和其他类似学校任教。

对优生学的兴趣，以及他在加拿大农场工作的经历，使费希尔对开办自己的农场产生了兴趣。在这些计划中，他得到了大学朋友的妻子Gudruna的鼓励，这使他结识了Ruth Eileen Gratton Guinness，即Gudruna的妹妹。Ruth Eileen和Gudruna的父亲Henry Gratton Guinness医生在她们年幼时去世，而Ruth Eileen年仅十六岁，知道母亲不会同意她这么年轻就结婚。因此，费希尔于1917年4月26日，在Ruth Eileen17岁生日后仅几天，在Ruth Eileen母亲不知情的情况下，与她举行了秘密婚礼。他们有两个儿子和七个女儿，其中一个在婴儿期夭折。

1919年，费希尔同时获得两个职位，于是放弃了数学教师的工作。卡尔·皮尔逊聘请他担任弗朗西斯·高尔顿实验室的首席统计学家，同时他还获得了Rothamsted农业实验站的统计学家职位。这是英国最古老的农业研究机构，成立于1837年，旨在研究营养和土壤类型对植物肥力的影响，这正符合费希尔对农业的兴趣。他接受了Rothamsted的职位，在那里他对统计学（特别是实验的设计与分析）和遗传学都做出了许多贡献。

在那里，他通过引入随机化概念和方差分析来研究实验设计，这些程序如今在世界各地使用。费希尔的想法是将实验安排为一组划分的子实验，这些子实验之间的区别在于对它们施加了一个或几个因素或处理。子实验的设计方式使得其结果差异可以通过统计分析归因于不同的因素或因素组合。这比当时在实验中一次只改变一个因素的现有方法有了显著进步，后者是一种相对低效的程序。

1921年，他引入了似然的概念。一个参数的似然与数据的概率成正比，它给出一个通常具有单一最大值的函数，他称之为最大似然。1922年，他给出了统计学的新定义。他声称，其目的是数据的简化，并确定了三个基本问题。这些是：

1. 指定数据所来自的总体类型；
2. 估计；以及
3. 分布。

费希尔发表了许多重要著作；特别是Statistical Methods for Research Workers（1925年）历经多版，他终生不断增补。这是一本关于他已在洛桑试验站开发的实验设计与分析方法的手册。费希尔的贡献包括发展了适用于小样本的方法，如戈塞特中的那些方法，以及发现了许多样本统计量的精确分布。费希尔发表了The design of experiments（1935年）和Statistical tables（1947年）。他的著作[3]：-

……彻底变革了农业研究；因为它们描述了如今全世界都在使用的方法，用于评估小样本实验的结果，以及安排实验试验以尽量减少因土壤异质性和生物材料不可避免的不规则性所造成的干扰。

在农业试验站期间，他用小鼠、蜗牛和家禽进行了育种实验，他获得的结果导致了关于基因显性和适合度的理论，这些理论发表于The Genetical Theory of Natural Selection（1930年）。

这项关于自然选择的工作使费希尔质疑在文明社会中，弱者和相对不育的人如何获得优于强壮健康个体的优势。他认为，通过自然适者生存来改善人类的方法正在被那些特别有利于适应较差者的因素人为改变。作为反对这一趋势的强烈倡导者，他提议家庭津贴应与收入成比例，以支持社会中适应良好的健康成员。正如人们可能预料的那样，这项政策非常不受欢迎，他几乎没有支持者。

1933年，卡尔·皮尔逊从大学学院的弗朗西斯·高尔顿优生学教授职位退休，费希尔被任命为讲席教授作为他的继任者。事实上，这个职位被分成两个，卡尔·皮尔逊的儿子伊根·皮尔逊也被任命为讲席教授。费希尔担任这个职位十年，于1943年被任命为剑桥大学Arthur Balfour遗传学教授。然而，在此之前，当1939年战争爆发时，他已经搬离伦敦，在Harpenden找到了临时住所。他于1957年从剑桥的讲席退休，但继续在那里履行职责两年，直到他的继任者被任命。然后他搬到阿德莱德大学，在那里继续他的研究，直到生命的最后三年。

1933年费希尔接替卡尔·皮尔逊，这颇具讽刺意味，因为两人长期不和。这场不和始于1917年，当时卡尔·皮尔逊发表了一篇论文，声称费希尔在1915年写的一篇论文中未能区分似然与逆概率。尽管此时费希尔的事业才刚刚起步，但他对卡尔·皮尔逊在未告知他的情况下发表了一篇批评他成果的文章感到愤怒。此外，他不接受卡尔·皮尔逊的批评，认为自己是对的。

事实上，这场不和的原因远不像通常所说的那样简单。标准的解释是，费希尔变得 bitter，是因为他遭受了严重的不公，他的论文被不懂生物学的数学家和不懂数学的生物学家拒稿。让我们举一个例子来说明，这实际上是一种过度简化。1918年，费希尔将他非常重要的论文On the correlation between relatives on the supposition of Mendelian inheritance提交给皇家学会。任命了两位审稿人R C Punnett和卡尔·皮尔逊，他们对论文进行了报告。两位审稿人都没有拒稿，然而，他们只是表达了保留意见，并明确表示论文中有一些方面他们无力评判。结果费希尔撤回了论文，将其提交给Transactions of the Royal Society of Edinburgh，在那里被接受。费希尔的新颖思想需要时间才被接受，这并不奇怪。

然而，当卡尔·皮尔逊利用他作为Biometrika编辑的职位，在1922年的一篇论文中攻击费希尔对卡方检验的使用时，这场不和变得激烈起来。然而，卡尔·皮尔逊走得更远，声称费希尔通过广泛发表错误结果，对统计学造成了损害。Royal Statistical Society随后拒绝发表费希尔的论文，他为此辞去该学会的职务以示抗议。当然，费希尔也抓住一切机会攻击卡尔·皮尔逊，公平地说，两人都表现出对对方的仇恨。即使在卡尔·皮尔逊于1936年去世后，费希尔仍继续攻击他，这使得大学学院的气氛非常紧张，因为卡尔·皮尔逊的儿子伊根·皮尔逊也在那里担任讲席。

费希尔于1929年当选为皇家学会会士，1938年被授予该学会的皇家奖章，并于1948年被授予该学会的达尔文奖章：-

……以表彰他对自然选择理论、其基因复合体概念以及显性进化所作的杰出贡献。

然后，在1955年，他被授予皇家学会的科普利奖章：-

……以表彰他为发展统计学的理论与应用、使生物学的一个广阔领域得以定量化所作的众多杰出贡献。

他于1934年当选美国艺术与科学院会士，1941年当选美国哲学会会士，1948年当选国际血液学会会士，1948年当选国家科学院 of the United States会士，1960年当选Deutsche Akademie der Naturforscher Leopoldina会士。多所机构授予他荣誉学位，包括哈佛大学（1936年）、加尔各答大学（1938年）、伦敦大学（1946年）、格拉斯哥大学（1947年）、阿德莱德大学（1959年）、利兹大学（1961年）以及印度统计研究所（1962年）。他于1952年被封为爵士。

费希尔的性格在[3]中描述如下：-

他能够展现出极大的魅力，并在友谊中充满温情。但他也如他自己所认识到的那样，是一种无法控制的脾气的受害者；而他对他所看到的科学真理的献身简直是充满激情的，因此他对那些被他判定为传播错误的人是一个不可调和的敌人。

他还有其他长处和短处[3]：-

作为一个敏锐的思想家，费希尔是杰出的；但他的著作对许多读者来说很难。事实上，他的一些教导通过其他人的书得到了最有效的传达，这些人能够简化他们的表达。作为一名讲师，费希尔对普通学生来说也太难了；他的课堂会迅速减少，直到只剩下两三个能跟上进度的学生，成为着迷的门徒。他作为管理者也不是特别成功；他或许未能理解普通人的局限性。但凭借他广泛的兴趣和敏锐的头脑，他是一个最令人振奋和富有同情心的谈话者。

费希尔的声誉因对优生学态度的变化而受损。在冈维尔与凯斯学院，他的窗户于2020年被移除。伦敦大学学院的一个曾以费希尔命名的实验室被重新命名。

R A Fisher's parents were Katie Heath, the daughter of a solicitor, and George Fisher, of Robinson and Fisher a firm of auctioneers in King Street, St James, London. Katie and George had seven children, four boys and three girls. After the birth of Geoffrey in 1876 and Evelyn in 1877, they named their third child, who was born the following year, Alan. He died at a very young age and Katie, being superstitious, decided that all their children from that time on would have a "y" in their name. Ronald Aylmer Fisher was the second of twins, but the older twin was still-born.

In 1904 Ronald entered Harrow, but this was a difficult time for the fourteen year old boy, for his mother died in that year of acute peritonitis. Despite this, he excelled at Harrow winning the Neeld Medal in 1906 in a mathematical essay competition open to the whole school. Fisher was awarded a £80 scholarship from Caius and Gonville College, Cambridge, which was necessary to finance his studies since his father had lost his fortune. In October 1909 he matriculated at Cambridge.

Although he studied mathematics and astronomy at Cambridge, he was also interested in biology. In his second year as an undergraduate he began consulting senior members of the university about the possibility of forming a Cambridge University Eugenics Society. He graduated with distinction in the mathematical tripos of 1912. His tutor, however, believed he could have done better, writing [3]:-

... if he had stuck to the ropes he would have made a first class mathematician, but he would not.

Awarded a Wollaston studentship, he continued his studies at Cambridge under Stratton on the theory of errors reading Airy's manual the Theory of Errors. It was Fisher's interest in the theory of errors that eventually led him to investigate statistical problems.

After leaving Cambridge, Fisher had no means of financial support and worked for a few months on a farm in Canada. He returned to London, taking up a post as a statistician in the Mercantile and General Investment Company. When war broke out in 1914 he enthusiastically tried to enlist in the army, having already trained in the Officers' Training Corps while at Cambridge. His medical test showed him A1 on all aspects except his eyesight, which was rated C5, so he was rejected. He became a teacher of mathematics and physics, teaching at Rugby and other similar schools between 1915 and 1919.

The interest in eugenics, and his experiences working on the Canadian farm, made Fisher interested in starting a farm of his own. In these plans he was encouraged by Gudruna, the wife of a college friend, and this led to him meeting Ruth Eileen Gratton Guinness, Gudruna's younger sister. Ruth Eileen and Gudruna's father, Dr Henry Gratton Guinness, had died when they were young and Ruth Eileen, only sixteen years of age, knew that her mother would not approve of her marrying so young. As a result Fisher married Ruth Eileen at a secret wedding ceremony without her mother's knowledge, on 26 April 1917, only days after Ruth Eileen's 17th birthday. They had two sons and seven daughters, one of whom died in infancy.

Fisher gave up being a mathematics teacher in 1919 when he was offered two posts simultaneously. Karl Pearson offered him the post of chief statistician at the Galton laboratories and he was also offered the post of statistician at the Rothamsted Agricultural Experiment Station. This was the oldest agricultural research institute in the United Kingdom, established in 1837 to study the effects of nutrition and soil types on plant fertility, and it appealed to Fisher's interest in farming. He accepted the post at Rothamsted where he made many contributions both to statistics, in particular the design and analysis of experiments, and to genetics.

There he studied the design of experiments by introducing the concept of randomisation and the analysis of variance, procedures now used throughout the world. Fisher's idea was to arrange an experiment as a set of partitioned sub-experiments that differ from each other in having one or several factors or treatments applied to them. The sub-experiments were designed in such a way as to permit differences in their outcome to be attributed to the different factors or combinations of factors by means of statistical analysis. This was a notable advance over the existing approach of varying only one factor at a time in an experiment, which was a relatively inefficient procedure.

In 1921 he introduced the concept of likelihood. The likelihood of a parameter is proportional to the probability of the data and it gives a function which usually has a single maximum value, which he called the maximum likelihood. In 1922 he gave a new definition of statistics. Its purpose was, he claimed, the reduction of data, and he identified three fundamental problems. These are:

1. specification of the kind of population that the data came from;
2. estimation; and
3. distribution.

Fisher published a number of important texts; in particular Statistical Methods for Research Workers (1925) ran to many editions which he extended throughout his life. It was a handbook for the methods for the design and analysis of experiments which he had developed at Rothamsted. The contributions Fisher made included the development of methods suitable for small samples, like those of Gosset, and the discovery of the precise distributions of many sample statistics. Fisher published The design of experiments (1935) and Statistical tables (1947). His books [3]:-

... revolutionized agricultural research; for they described the methods, now used the world over, for evaluating the results of small sample experiments and for so laying our experimental trials as to minimise the disturbances due to heterogeneity of soils and the unavoidable irregularity of biological material.

While at the Agricultural Experiment Station he had conducted breeding experiments with mice, snails and poultry, and the results he obtained led to theories about gene dominance and fitness which he published in The Genetical Theory of Natural Selection (1930).

This work on natural selection led Fisher to question the way that in civilised societies weak and relatively infertile people obtained advantages over strong healthy individuals. He felt that the natural survival of the fittest method of improving the human race was being artificially changed by factors that specifically benefited the less well adapted. A strong advocate of measures to counter this trend, he proposed that family allowances should be proportional to income to support the well-adapted healthy members of society. As one might expect, this policy was very unpopular and he found few supporters.

In 1933 Karl Pearson retired as Galton Professor of eugenics at University College and Fisher was appointed to the chair as his successor. In fact the post was split in two, with Karl Pearson's son Egon Pearson also being appointed to a chair. Fisher held this post for ten years, being appointed as Arthur Balfour professor of genetics at the University of Cambridge in 1943. Before this, however, he had moved away from London when war broke out in 1939, finding temporary accommodation at Harpenden. He retired from his Cambridge chair in 1957 but continued to carry out his duties there for another two years until his successor could be appointed. He then moved to the University of Adelaide where he continued his research for the final three years of his life.

There was a certain irony in the fact that Fisher succeeded Pearson in 1933 for the two had a long running dispute. The dispute began in 1917 when Pearson published a paper claiming that Fisher had failed to distinguish likelihood from inverse probability in a paper he wrote in 1915. Although at this stage Fisher was only starting out on his career, he felt angry that Pearson had published an article which was critical of his results without telling him that he was about to do so. Moreover, he did not accept Pearson's criticism, feeling that he was correct.

In fact the reasons for the feud were not nearly as simple as those usually given. The standard explanation is that Fisher became bitter because he suffered serious injustice having his papers rejected by mathematicians who did not understand biology and biologists who did not understand mathematics. Let us take an example to show that in fact this is an over-simplification. In 1918 Fisher submitted his very important paper On the correlation between relatives on the supposition of Mendelian inheritance to the Royal Society. Two referees, R C Punnett and Pearson, were appointed and reported on the paper. Neither referee rejected the paper, however, they both merely expressed reservations and stated clearly that there were aspects of the paper that they were not competent to judge. In the event Fisher withdrew the paper and submitted it to the Transactions of the Royal Society of Edinburgh where it was accepted. It is not surprising that Fisher's novel ideas took time to become accepted.

The feud became bitter, however, when Pearson used his position as editor of Biometrika to attack Fisher's use of the chi-squared test in a 1922 paper. Pearson went much further, however, and claimed that Fisher had done a disservice to statistics by widely publishing erroneous results. The Royal Statistical Society then refused to publish Fisher's papers and he resigned from the Society in protest. Of course Fisher also took every opportunity to attack Pearson, and it would be fair to say that each showed hatred towards the other. Even after Pearson died in 1936, Fisher continued his attack on him, which made the atmosphere in University College a very difficult one with Pearson's son Egon Pearson also holding a chair there.

Fisher was elected a Fellow of the Royal Society in 1929, was awarded the Royal Medal of the Society in 1938, and was awarded the Darwin Medal of the Society in 1948:-

... in recognition of his distinguished contributions to the theory of natural selection, the concept of its gene complex and the evolution of dominance.

Then, in 1955, he was awarded the Copley Medal of the Royal Society:-

... in recognition of his numerous and distinguished contributions to developing the theory and application of statistics for making quantitative a vast field of biology.

He was elected to the American Academy of Arts and Sciences in 1934, the American Philosophical Society in 1941, the International Society of Haematology in 1948, the National Academy of Sciences of the United States in 1948, and the Deutsche Akademie der Naturforscher Leopoldina in 1960. Various institutions awarded him an honorary degree including Harvard University (1936), University of Calcutta (1938), University of London (1946), University of Glasgow (1947), University of Adelaide (1959), University of Leeds (1961), and the Indian Statistical Institute (1962). He was knighted in 1952.

Fisher's character is described in [3] as follows:-

He was capable of tremendous charm, and warmth in friendship. But he also was the victim, as he himself recognised, of an uncontrollable temper; and his devotion to scientific truth as he saw it being literally passionate, he was an implacable enemy of those whom he judged guilty of propagating error.

He had other strengths and weaknesses too [3]:-

As a penetrating thinker Fisher was outstanding; but his writings are difficult for many readers. Indeed, some of his teachings have been most effectively conveyed by the books of others who have been able to simplify their expression. As a lecturer also, Fisher was too difficult for the average student; his classes would rapidly fall away until only two or three students who could stand the pace remained as fascinated disciples. Nor was he particularly successful as an administrator; he perhaps failed to appreciate the limitations of the ordinary man. But with his wide interests and penetrating mind he was a most stimulating and sympathetic conversationalist.

Fisher's reputation suffered in the changing attitudes to Eugenics. At Gonville and Caius College, his window was removed in 2020. A laboratory at University College, London that had been named for Fisher was renamed.