Thus, he wrote, “People lay too much stress on apparent specialities, thinking over-rashly perhaps, that because a man is devoted to some particular pursuit, he could not possibly have succeeded in anything else.” Galton held that those who reach high levels of achievement in one field could have risen as high in any number of others. Galton’s second contention was that intelligence is a single entity that can be directed into different activities. Galton sent a copy of his book to his cousin Charles Darwin, who replied, saying that hitherto he had always supposed that there was not much difference between people in intelligence (“excepting fools”) and that differences in achievement were largely due to differences in application, but that after reading Hereditary Genius he was convinced Galton was right. the greatest and the least of English intellects, is enormous.” This is widely accepted today but was a novel idea in the mid-19th century. First, he asserted that people vary greatly in intelligence: “he range of mental powers between. However, his most controversial work was on intelligence, and it is this that we shall discuss in these columns.Īll of Galton’s important insights on intelligence can be found in his first book, Hereditary Genius, published in 1869 when he was 47 years old. He found that the life span of monarchs is about the same as that of their subjects, and concluded that prayers, even in the millions, are not effective. He argued that if prayer works, monarchs should live longer than ordinary folks, since millions of their subjects pray for them to enjoy a long life. Galton published papers on many topics, some of them quite controversial. He also solved the subtleties of regression to the mean, which some statisticians consider to be one of the greatest achievements in the history of science. He devised the method for calculating the correlation coefficient, which is today used universally in the social sciences. Galton’s statistical work was some of his most important, and laid the foundations for many of his other achievements.