Analysis of America's Modern Melting Pot 735 the returns are a representative sample, their validity, so far as such validity may be impaired by the smallness of the sample, may be gauged by the probable error. If, in any particular case, the finding is less than two or three times its probable error, it means that, statistically, because of the small size of the sample, the quota fulfillment is not reliable. If, however, the quota fulfillment finding is more than two or three times thee size of its accompanying probable error, it means that, statistically, the requirements of an accurate survey have been met. This can be judged for each particular quota fulfillment on each chart. In each table we have listed the institutions which did supply and those which did not supply the returns. As a general thing, the men in charge of the custodial institutions of the United States are not unmindful of the problem of alien inadequacy, and consequently they are anxious to aid in any studies which will provide this committee with data necessary for the intelligent solution of the problem in the interests of race conservation. The Chairman. We appreciate the amount of labor involved in securing these data and, if there is no objection, Doctor Laughlin is authorized, in future correspondence, to convey to the authorities in charge of custodial institutions the thanks of this committee for collaboration in these studies. There is no objection. So ordered. The Feeble-Minded The Chairman. We are now ready to hear the results of the scientific studies made upon the several specific types of socially inadequate, with particular reference to their frequency in the different immigrant nationalities in the United States. Doctor Laughlin. Mr. Chairman, the first and, in many ways, the most important or dangerous group of the socially inadequate are the feeble-minded or mentally deficient. Mental ability is a relative term, because the native intelligence grades within the whole population vary, by a finely graduated scale, from superior intelligence and high talent at the upper end to abject idiocy at the foot. In these researches, the term "feeble-minded" will be used in a technical sense. Here it means an individual who is so deficient mentally that he is unable to cope with the complexities of the social organization in which he finds himself, without custodial care. According to the crime prevention bill which the municipal court of Chicago is asking the Legislature of Illinois to enact, the term "mental defective" in relation to crime, is defined as follows: "(a) A person who has a defect of intelligence, or (b) a defect of affectivity of emotion, (c) a defect of will of such a degree that he has criminal propensities, and while at large is a menace to the person and property of others." Of course, there are many other aspects of feeble-mindedness besides the criminalistic; for instance, the moral, the economic, and the biological. Each of those aspects has its own specialized definition. Mr. Cable. What is the extent of feeble-mindedness in the whole country, both in the native and immigrant population groups? Doctor Laughlin. The determination of the answer to your question is the direct purpose of these investigations, but before I give you the results of my survey, I may be permitted to present to the committee the findings of other studies which may throw light upon the present researches. According to different surveys which have been made in different States of the Union, and one of them in Great Britain, the generally accepted ratio for the occurrence of feeble-mindedness in the whole population of America and England is about 1200. This is the general result. According to a compilation made by the committee on subnormal children in the public schools of Iowa, printed in the October, 1922, issue of the Bulletin of Iowe State Institutions, the best estimates on the frequency of this defect are summarized as follows: [chart] Ratio of feeble-mindedness in the population. Estimates made by:&&&One in Royal Commission of Great Britain...&&&217 Porter County, Ind., survey...&&&138 New Castle County, Del., survey...&&&262 Nassau County, N.Y., survey...&&&183 Doctors Goddard, Johnson, Fernald...&&&250 New York Commission on Mental Defectives...&&&242 Report by Charles H. Strong - New York charities...&&&294 Massachusetts Society for Mental Hygiene...&&&282 F. Kuhlman, Faribault, Minn....&&&200 England and Wales, estimate...&&&217