Chapter XIV: Quantitative Definitions of the Borderline 304

A. DIFFERENT FORMS OF QUANTITATIVE DEFINITIONS 304

B. COMMON CHARACTERISTICS OF QUANTITATIVE DEFINITIONS 308

C. PRACTICAL ADVANTAGES OF THE PERCENTAGE METHOD 311

D. THEORETICAL ADVANTAGE OF THE PERCENTAGE METHOD WITH CHANGES 317
IN THE FORM OF THE DISTRIBUTIONS

BIBLIOGRAPHY ON TESTED DELINQUENTS 324

Other References Cited 329

APPENDICES 344

INDEX 353

LIST OF TABLES AND FIGURES

TABLES

I. Age distribution of deaths in the general population and of 30
feeble-minded in institutions

II. Mortality of institutional deficients in the United States 31
compared with the general population

III. Test borderlines with randomly selected Minneapolis 89
15-year-olds

IV. Results with the Binet tests for mental ages XI and XII 98
(1908 series)

V. Percentages of mentally retarded children as tested with the 106
Binet 1908 Scale

VI. Mental retardation of children as tested with the Binet 1911 111
Scale

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 125
positions among the delinquent boys of Glen Lake

X. Binet 1911 tests of boys consecutively admitted to the 151
Detention Home at Thorn Hill, Allegheny County

XI. Frequency of tested deficiency among over 9000 delinquents 159

XII. Age and grade distribution of elementary school pupils in 178
Minneapolis

XIII. School retardation of Minneapolis delinquents and elementary 179
school pupils

XIV. Indices of frequency and amount of school retardation for 183
Minneapolis delinquents and elementary school pupils

XV. Percentage of pupils 12 and 13 years of age most seriously 193
retarded in school

XVI. School position of delinquents at Glen Lake relative to 204
their intellectual development

XVII. Goring's data as to the percentage of mental defectives 213
among men convicted of various offenses

XVIII. Goring's data as to groups of crimes committed most 214
frequently by those mentally deficient

XIX. Four-fold correlation table for juvenile delinquency and 222
deficiency in Minneapolis

XX. Average Intelligence Quotients of children of different 296
ability

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 32
the general population

2. School retardation of Minneapolis delinquents compared with 180
elementary school boys

3. Hypothetical development curves (normal distributions) 253

4. The question of equivalence of year units 265

5. Hypothetical development curves (changing form of 277
distribution.)

6. Tests of the development of memory processes. Medians at 285
each age for the central tendencies of the tests

7. Different types of development. Medians at each age for the 286
central tendencies of the tests

8. Forty tests of development. Distribution at each age for the 287
central tendencies of the tests

9. Relative positions at each age of the median and of 299
corresponding bright and retarded children with the Form
Board Test

DEFICIENCY AND DELINQUENCY