Pearson correlation, as well as both the widely used correction for attenuation (1907), and the earliest version of a 'factor analysis (Lovie & Lovie, 1996, p. 81). His statistical work was not appreciated by his University College colleague Karl Pearson and there was a long feud between them. Although Spearman achieved most recognition in his day for his statistical work, he regarded this work as subordinate to his quest for the fundamental laws of psychology, and he is now similarly renowned for both. Charles Spearman always insisted that his work be applied in psychiatry and urged so in his Maudsley lecture to the Royal Medico-Psychological Association. While some work has been made on these lines by pupils and associates of his, the development of factor analysis as a tool of psychiatry followed a different path than he had intended. Regardless, his indirect contributions towards psychiatry were considerable. Spearman's life both began and ended in the city of London. He had three daughters along with one son, who died early on in 1941 in Crete. Theory of intelligence A record of Spearman's views on g (and also those of Godfrey Thomson and Edward Thorndike) was made in the course of the Carnegie-sponsored International Examinations Inquiry Meetings. Here, Spearman gives a compact summary of his findings and theory of g''':There was also another co-factor as proposed by Spearman that was special intelligence. The special intelligence was for individuals who accomplished high success results in the same tests. However, later Spearman introduced group factor that was particular to those correlations that were not a result of factor g or s. His ideas were in 1938 criticized on paper by psychologist Louis L. Thurstone who argued his own experiments showed that intelligence formed seven primary categories: numerical, reasoning, spatial, perceptual, memory, verbal fluency and verbal comprehension. Thurstone ultimately agreed with Spearman that there was a general factor among ability measures. Subsequently, Raymond Cattell (1963) also supported the general ability concept theorized by Spearman but highlighted two forms of ability, distinguished by their development in older age: fluid and crystallized intelligence. As time progressed, Spearman increasingly argued that g was not, from a psychological point of view, a single ability but composed of two very different abilities which normally worked closely together. These he called "eductive" ability and "reproductive" ability. The former term comes from the Latin root "educere" – which means to "draw out"