Psychological Investigations 237
Galton confesses that the first results of his inquiry amazed him. He had begun by questioning friends in the scientific world, because he thought they were the most likely persons to give accurate answers, and to his
astonishment most of the men of science replied that mental imagery was unknown to them.
"They had no more notion of its true nature than a colour-blind man, who has not
discerned his defect, has of the nature of colour. They had a mental deficiency of which they were unaware, and naturally enough supposed that those who were normally endowed were
romancing." (p. 302.)
The members of the French Institute exhibited a like incredulity as to the reality of the visualising faculty. On the other hand in general society Galton found many men and women with the power of visualising. He was thus compelled to the conclusion that, whatever its cause might be, scientific men as a class have feeble powers of visual representation.
"My own conclusion is, that an over-readiness to perceive clear mental pictures is antagon
istic to the acquirement of highly generalised and abstract thought, and that if the faculty of producing them was ever possessed by men who think hard, it is very apt to be lost by disuse. The highest minds are probably those in which it is not lost, but subordinated, and is ready for use on suitable occasions. I am, however, bound to say, that the missing faculty seems to be replaced so serviceably by other modes of conception, chiefly I believe connected with the motor sense, that men who declare themselves entirely deficient in the power of seeing mental pictures can nevertheless give lifelike descriptions of what they have seen, and can otherwise express themselves as if they were gifted with a vivid visual imagination. They can also
become painters of the rank of Royal Academicians." (p. 304.)
Galton data were collected from 100 adult men, of whom 19 were Fellows of the Royal Society, three times as many more of distinction in other kinds of intellectual work, and the remainder of less note. He had also returns from 172 Charterhouse boys who had been interested in the matter by their Science Master Mr W. H. Poole. The whole of the original material-with much that Galton collected later for a new edition of the Inquiries into Human Faculty-is in the Galtoniana, and would be well worth working up by more modern statistical methods than were available in 1879.
What Galton does in this paper is to arrange the answers to each of his questions-vividness of imagery, colour representation, extent of field of mental view-in ranks by order of intensity, for his 100 adult males and for two groups of the Charterhouse boys : A for the upper classes, B for the five lower classes of the school. When the material was ranked Galton cited the Highest, the first Suboctile, the first Octile, the first Quartile, the Median, the last Quartile, the last Octile, the last Suboctile and the Lowest Answers. The intensities exhibited by the two Charterhouse groups at the various selected ranks were very similar, and the adult males were not very dissimilar from these, but they did not form as regular a series as the boys. They were avowedly not members of a true statistical group "being an aggregate of one class of persons who replied because they had remarkable powers
of imagery and had much to say, of another class of persons, the scientific, who on the whole are very deficient in that gift, and of a third class who may justly be considered as fair samples of adult males." (p. 312.)