LIST OF TABLES AND FIGURES
| Tables | ||
|---|---|---|
| I. | Age distribution of deaths in the general population and of feeble-minded in institutions | [30] |
| II. | Mortality of institutional deficients in the United States compared with the general population | [31] |
| III. | Test borderlines with randomly selected Minneapolis 15-year-olds | [89] |
| IV. | Results with the Binet tests for mental ages XI and XII (1908 series) | [98] |
| V. | Percentages of mentally retarded children as tested with the Binet 1908 Scale | [106] |
| VI. | Mental retardation of children as tested with the Binet 1911 Scale | [111] |
| VII. | Borderlines with the Point Scale | [115] |
| VIII. | Test ages of the Glen Lake group of delinquent boys | [124] |
| IX. | Intellectual development relative to life-ages and school positions among the delinquent boys of Glen Lake | [125] |
| X. | Binet 1911 tests of boys consecutively admitted to the Detention Home at Thorn Hill, Allegheny County | [151] |
| XI. | Frequency of tested deficiency among over 9000 delinquents | [159] |
| XII. | Age and grade distribution of elementary school pupils in Minneapolis | [178] |
| XIII. | School retardation of Minneapolis delinquents and elementary school pupils | [179] |
| XIV. | Indices of frequency and amount of school retardation for Minneapolis delinquents and elementary school pupils | [183] |
| XV. | Percentage of pupils 12 and 13 years of age most seriously retarded in school | [193] |
| XVI. | School position of delinquents at Glen Lake relative to their intellectual development | [204] |
| XVII. | Goring's data as to the percentage of mental defectives among men convicted of various offenses | [213] |
| XVIII. | Goring's data as to groups of crimes committed most frequently by those mentally deficient | [214] |
| XIX. | Four-fold correlation table for juvenile delinquency and deficiency in Minneapolis | [222] |
| XX. | Average Intelligence Quotients of children of different ability | [296] |
| XXI. | Test records with random 15-year-olds | [344] |
| XXII. | Test records with delinquents at the Glen Lake Farm School | [349] |
| Figures | ||
| 1. | Mortality among feeble-minded in institutions compared with the general population | [32] |
| 2. | School retardation of Minneapolis delinquents compared with elementary school boys | [180] |
| 3. | Hypothetical development curves (normal distributions) | [253] |
| 4. | The question of equivalence of year units | [265] |
| 5. | Hypothetical development curves (changing form of distribution.) | [277] |
| 6. | Tests of the development of memory processes. Medians at each age for the central tendencies of the tests | [285] |
| 7. | Different types of development. Medians at each age for the central tendencies of the tests | [286] |
| 8. | Forty tests of development. Distribution at each age for the central tendencies of the tests | [287] |
| 9. | Relative positions at each age of the median and of corresponding bright and retarded children with the Form Board Test | [299] |
DEFICIENCY AND DELINQUENCY
PREFACE
In undertaking in 1912 to examine the mental development of delinquents for the clinic started and supported by the Juvenile Protective League of Minneapolis, in connection with the Juvenile Court, I soon became convinced that a safer method for evaluating the limit of feeble-mindedness with tests was more needed than masses of new data. The researches that have been published in the past three years do not seem to have changed this situation. Numerous studies with psychological tests are already available, but they generally treat of average rather than borderline conditions. In the field of delinquency the work of testing has been carried on with especial activity. Here, as well as elsewhere, the conclusions seem likely to be misleading unless social workers better appreciate the real place of mental tests, their value and their limitations.
The tables of a few hundred juvenile delinquents and school children examined in Minneapolis, which are presented in this book, indicate the occasion rather than the aim of the present study. The purpose is mainly to help clear the ground for other work with mental tests, and especially to put the determination of feeble-mindedness by objective examination with the Binet or other scales on what seems to me a sounder basis. Furthermore, the results of objective testing which have been so rapidly accumulating in the field of delinquency need to be assembled and reorganized in order to avoid confusion. It is especially desirable to discover a conservative basis for objective diagnosis of deficient intellectual capacity in order to prevent very useful testing systems from becoming unjustly discredited and to preserve the advance that has been made.
The work out of which this monograph grew was begun through the encouragement of Judge Edward F. Waite of the Hennepin County Juvenile Court. His earnest co-operation and my interest in the field of mental testing has led me to continue the study. Judge Waite's insight into his court problems resulted in the early organization of a Juvenile Court clinic (153, 170) in Minneapolis. The clinic is in charge of Dr. Harris Dana Newkirk, who has contributed materially to this study by his thorough medical examination of each of the cases brought to him. To the staff at the probation office I am also much indebted.
The earnest help of Superintendent D. C. MacKenzie, of the Glen Lake Farm School for the juvenile delinquents of Hennepin County, made a close study of our most interesting group of boys much more profitable personally than I have shown here. For detailed expert work in tabulation and in examinations I wish to express my thanks to my advanced students, a half dozen of whom have contributed materially to the data of this book.
James Burt Miner.
Carnegie Institute of Technology