A government inquiry of school teachers in Switzerland, who had charge of 490,252 school children, reported that 1.2% were so feeble mentally as to need training in special classes. Only about a tenth of this number were then being instructed in separate classes (181, p. 17).
Great Britain first gave legal recognition to the class of feeble-minded above the imbeciles in its Education Act of 1898, following a report of a departmental committee of its National Board of Education growing out of the inquiries of Francis Warner. This committee estimated the proportion of this class as approximately 1% of the elementary school population ([181]). In discussing the comparative estimates on the general and school populations I have already referred to the estimate of Tredgold based upon an elaborate analysis of the most extensive data ever collected,—that gathered by the British Royal Commission on the Care and Control of the Feeble-Minded. While the Commission's investigators enumerated 0.79% among the school as mentally defective, Tredgold's estimate based on his analysis of their report was that 0.83% of the school population in England and Wales were above the grade of imbecile but still feeble-minded (204, p. 157). The variability of the estimates collected by the Royal Commission from various cities probably indicates the subjective character of the standards of deficiency. They varied from an estimate of 0.24% of the elementary school population in Durham to 1.85% in Dublin (204, p. 159). The Commission says regarding estimates as to communities other than those reported by their medical investigator, for Newcastle the “number of feeble-minded children of school age” (morons) was 0.25%, for Leeds the estimate was 0.80%, for London 0.50% or 0.60%, for Bradford 0.50%, for Dublin about 1% and for Birmingham about 1% of the school population. Dr. Francis Warner's general estimate was 0.8%. We have thus variations in estimates from 0.25%, 0.5%, 0.80% to 1% and some 2% (167, p. 90). For the rural areas the estimates were generally less.
A careful estimate has been made with a different method by Karl Pearson on the basis of a classification by teachers of school children in Great Britain into nine different classes each especially defined and extending from the imbecile to the genius. This distribution of the children was then fitted to the normal probability curve. On this basis Pearson estimated that 1.8% would fall in the “very dull group,” defined as having “a mind capable of holding only the simplest facts, and incapable of grasping or reasoning about the relationship between facts; the very dull group covers but extends somewhat further up than the mentally defective.” Lower down would be 0.1% in the imbecile group. He says further regarding this estimate: “It is deduced from three series covering between 4000 and 5000 cases, and the three separate results are in several accord. It will, I think, be possibly useful for other inquirers, and it endeavors to give quantitative expression to our verbal definitions of the intellectual categories” ([166]).[[7]]
In 1914 Pearson cites estimates of mentally defective children in several cities by teachers and medical officers based upon the recommendation of elementary school children for special schools and classes. These were, for London: boys, 1.59%; girls, 1.09%. For Liverpool: boys, 0.827%; girls, 0.618%. The corresponding figure for both sexes in Stockholm is 1.23%. He concludes that “something between 1% and 2% is true for England. Dr. James Kerr, Medical Research Officer, thinks that the final estimate will be nearer the latter value.”
After giving a table of the percentages at each age in the elementary schools of Stockholm, Pearson says: “Judged from this table it would seem that the most reasonable estimate of the prevalence of mental defect is to be formed when all the mental defectives have been definitely selected and the normal children have not yet begun to leave school, i. e., at the ages 11 and 12. For Stockholm this leads up to a mentally defective percentage of about 1.5” (167, p. 6-8). In another place he says that the members of special classes are selected practically for the same reason, i. e., because they are school inefficients, the bulk of whom will, no doubt, unless provided for become “social inefficients” (164, p. 48). Since some were not selected because of intellectual deficiency, our social assistance group should be somewhat smaller.
In 1909-10 the actual number in the schools for mental defectives maintained by the London County Council was 0.9% of the enrollment of the London elementary Schools ([143]). The 1912 report of the London County Council shows 7357 children enrolled in its local schools for mental defectives, which is 1.1% of the average attendance from 1912-1913 in the elementary county council schools and voluntary schools of London (144, p. 44).
Following a discussion in the Australian Medical Congress of 1911 the Minister of Public Instruction called for returns as to the number of feeble-minded in the Australian public elementary schools between 5½ and 14 years of age inclusive. The questionnaire used the definitions of the British Royal Commission as a description of the various degrees of retardation and brought returns from 2,241 of the state schools, all except 57. For their average attendance of 175,000 children, these teachers classified 1.9% as backward from accidental causes, 2% mentally dull, 0.42% feeble-minded imbeciles or idiots, and 0.6% epileptics. To this would be added 0.19% for children in the idiot asylums. The report states that “the teachers' estimates will thus be realized to be an absolute minimum, dealing only with the intermediate grades, and not including the gross cases (idiots, etc.) on the one hand and the less marked high grades of feeble-minded on the other” ([70]).
The census made by the Bureau of Health of Philadelphia through the principals of schools in 1909 covered 157,752 elementary school children of whom 1.9% above the 0.28% who could “properly be in custodial institutions 'were classed' as backward children who require special instruction by special methods in small special classes” ([168]).
A survey of the school population in the Locust Point District of Baltimore was made by Dr. C. Macfie Campbell.[[8]] The district surveyed was, however, not considered typical of Baltimore, but was a sample of an industrial district in which the majority of families are “close to the poverty line, and too often below it.” Out of a school population of 1,281 children, 166 (13%) were “found to have special requirements on account of their mental constitution.” Among these, 22 (1.7%) “showed a pronounced mental defect, which eliminated any prospects of their becoming self-supporting.”
The city of Mannheim ([147]), which perhaps cares for its exceptional children better than any other in the world, was in 1911-1912 caring for 0.7% of the children in its Volkschule in Hilfsklassen which do not take them beyond the fourth grade. There were 12% more who were backward in school and being taught in Forderklassen where they may reach the sixth grade. Including the exceptionally bright who were also in special classes, 18% all together of its school children were not in the regular Hauptklassen of the eight grades. To these would be added those sent to special institutions. When we estimate, therefore, that we are justified at present in sending 1% of the children in school to special classes because their intellectual deficiency is such that the bulk of them cannot get along without social assistance, we are naming about the proportion already thus cared for in several foreign cities.