X. THE SIGNIFICANCE OF LITERACY
Reflection will show at once the great importance of reading for school progress, since our schools are virtually reading schools. Almost no subjects included in the curriculum can be learned without mastery of reading. Also the importance of literacy for life in modern times can scarcely be overstated. Those who learn to read easily at an early age thus have a natural advantage; while those of good intelligence, who have difficulty, should be assisted in every way to learn.
There are certainly very few children of IQ over 100, with normal eyes and ears, who do not learn with ease to read. A census would doubtless show that most cases of special disability in this respect lie between 50 and 100 IQ, that is, in the lower half of the distribution for general intelligence. Fildes, who measured the general intelligence of twenty-six non-readers, whom she studied, found them distributed as follows, with respect to IQ (Stanford-Binet):
| IQ 111 | 1 | child |
| IQ 82–88 | 4 | children |
| IQ 70–79 | 8 | children |
| IQ 50–69 | 13 | children |
It may be argued that children who cannot read necessarily tend to fall low on Stanford-Binet, because the tests composing the scale are weighted against non-readers. The validity of this argument is doubtful, in view of the fact that but four out of seventy-four tests (not including alternates, of which none require reading) directly involve ability to read or spell. As a matter of fact, Fildes found no correlation among her twenty-six subjects, between IQ and ability to read, as measured by reading tests. “Two of the worst readers were the least intelligent and most intelligent boys. The three worst cases examined, i.e., cases with no reading power at all, had intelligence quotients of 61, 79, and 78 respectively. Many defective boys with such high intelligence quotients read quite well.”[[13]]
Non-readers who fall between 80 and 100 IQ are especially worthy of attention, since they have sufficient general intelligence to make considerable use of reading, and to suffer a special handicap from illiteracy.
It may be confidently stated, as a result of the research of the past five years, that all children of average or better than average general intelligence are capable of literacy; and that very early use of and interest in reading are strongly symptomatic of general superiority in selective thinking. From these facts we may hark back to the conclusion of the physiological psychologists, Ladd and Woodworth: “Indeed, the entire cerebrum would seem to be, of necessity, involved in man’s linguistic attainments and uses.” Mastery of language is, as Binet concluded, one of the most reliable indications of competence in general.