Chapter V. ADAPTING THE PERCENTAGE DEFINITION TO THE BINET SCALE 82 A. THE BORDER REGION FOR THE MATURE 82 (a) Indication from a Random Group 82 (b) The Present Tendency Among Examiners 95 B. THE BORDER REGION FOR THE IMMATURE 104 (a) For the Binet 1908 Scale 104 (b) Data for Other Developmental Scales 110 (c) The Change in Interpreting the Borderline for the 116 Immature Chapter VI. DELINQUENTS TESTING DEFICIENT 122 A. AT THE GLEN FARM SCHOOL FOR BOYS, HENNEPIN COUNTY, 122 MINNESOTA B. COMPARISON OF TESTED DEFICIENCY AMONG TYPICAL GROUPS OF 127 DELINQUENTS (a) Women and Girl Delinquents in State Institutions 128 (b) Women and Girl Delinquents in Country and City 134 Institutions (c) Men and Boy Delinquents in State Institutions 141 (d) Men and Boy Delinquents in County and City 148 Institutions C. SUMMARY OF TESTED DEFICIENCY AMONG DELINQUENTS 158 Chapter VII. CHECKING THE BINET DIAGNOSIS BY OTHER METHODS 170 Chapter VIII. SCHOOL RETARDATION AMONG DELINQUENTS 177 A. IN MINNEAPOLIS 177 B. SCHOOL RETARDATION AMONG OTHER GROUPS OF DELINQUENTS 185 Chapter IX. COMPARISON OF THE SCHOOL TEST AND THE BINET TEST 189 A. PRACTICAL USES OF THE SCHOOL TEST 190 (a) Estimating the Frequency of Deficiency by School 190 Retardation (b) School Retardation as a Warning of the Need for 194 Examination (c) School Success as a Check on the Binet Diagnosis 197 B. CHECKING DEFICIENCY AMONG DELINQUENTS BY THE SCHOOL TEST 199 Chapter X. BAD SCHOOL ADJUSTMENT AS A CAUSE OF DELINQUENCY 203 Chapter XI. DEFICIENCY AS A CAUSE OF DELINQUENCY 210 A. THE CHANCES OF THE MENTALLY DEFICIENT BECOMING DELINQUENT 211 B. THE CORRELATION OF DEFICIENCY AND DELINQUENCY 218 C. THE CAUSES OF DELINQUENCY 224 (a) Constitutional Factors 224 (b) External Factors 225 (c) Weighing Heredity Against Environment 229 (d) The Criminal Diathesis 234 Chapter XII. SUMMARY AND SUGGESTIONS 239 PART II. THEORETICAL CONSIDERATIONS Chapter XIII. THE THEORY OF THE MEASUREMENT OF MENTAL DEVELOPMENT 252