Nervous instability may be found in combination with any degree of IQ, apparently, from dullest to brightest. The relation between them is not certainly known, though there is now considerable indication that the correlation between stability and intellect will be found to be positive and high (but not perfect). This would mean that there are very probably more ill-balanced children among the stupid than elsewhere in the distribution of IQ. That organic quality, which shows itself in superior intelligence, robustness, and longevity, also shows itself in nervous stability, more likely than not. A nervous child, who is also very stupid, will, of course, learn under individual instruction only what his limited intelligence will permit. The methods of mental measurement enable us to differentiate between the nervous child who can learn much, and the nervous child who can learn very little, under individual training. VII. A FOUR-YEAR STUDY OF A NON-READER From February, 1918, to May, 1922, the present writer studied and taught a non-reader, a schoolboy. X was brought to the Psychological Laboratory at Teachers College, in February, 1918, by his mother. The complaint was that the child could not learn to read, and on this account he had been suggested by his teachers for the ungraded class, in which feeble-minded children are taught. His mother, an intelligent woman, could scarcely believe X to be feeble-minded, because he “is very quick about things around home, is keen and capable about doing errands for money, and though he cannot read, gets around the city by himself.” She felt, however, that a boy who after over six years of instruction still remained totally illiterate must require special advice of some kind. Accordingly, when the suggestion in reference to the ungraded class was made, the mother took X to the Neurological Institute, where an examination was made, in the Psychological Laboratory. The report was then given that the child was not a proper pupil for such a class, and the matter was referred to Teachers College. X was born on September 23, 1906. He was therefore 11 years and 5 months old when he was first seen by the present writer. His school history showed that he started to school in kindergarten at the age of 5 years, and went into the first grade at 6 years. He had been “left back” in nearly every class, after the study of reading began. He spent three terms in 1A; one term in 1B; two terms in 2A; two terms in 2B; two terms in 3A; and was, when first examined, repeating 3B. In 3B he was reported as “deficient in everything except conduct.” In conduct he was rated always as B+ or A. The teachers said they could not teach him.