Boys 8-16 Years of Age
| Non-Deficient | Deficient | Total | |
|---|---|---|---|
| Non-Delinquent | 22,305 | 109 | 22,414 |
| Delinquent | 268 | 4 | 272 |
| Total | 22,573 | 113 | 22,686 |
The total number of boys is taken from the census of school children for 1915-16 compiled by the attendance department of the Board of Education. It includes those in public, parochial and private schools and those not attending. The number of delinquent boys is taken from the report of the Juvenile Court of Hennepin County, Tables H and I. The number of repeaters and the proportion of delinquent cases dismissed at the hearing are subtracted from the total number of new cases.
The difference between a correlation of .29, the highest I found, and .59, Goring's lowest result, indicates that conviction for felony in Great Britain is more closely associated with deficiency than juvenile delinquency is associated with deficiency in such communities as Minneapolis. It is to be remembered, however, that Goring's calculation gave the convicts a life-time in which to be convicted, while ours gave the boys only 16 years. The relation of potential delinquency after 16 years of age to deficiency might be greater among Minneapolis males than the corresponding relation we found among the boys; but the difference in these correlations is more easily explained by supposing that the type of serious delinquency represented by sentences to penal servitude, in England at least, is more closely related to deficiency than are the lighter forms of delinquency found among the youth of an American city.
The most significant fact demonstrated by the correlations between juvenile delinquency and deficiency is that there is a positive relationship which is significant in amount. With the maximum estimate the correlation is nearly 6 times its error. This is the first time that the relationship has actually been calculated in connection with any group of juveniles. We can say that when a Minneapolis boy is below the average in tested ability for his age, he is most likely to be .16 to .29 of the same amount below the average in legal conduct, both measurements being in corresponding units.
What then, is the significance of correlation in answering the problem of causation? So far as the statistical method itself is concerned it shows only a mathematical functional relation between the conditions measured, not a physiological relationship. In other words a correlation between deficiency and delinquency might be explained by both conditions being related to some more fundamental factor which might be the causal factor involved. One cannot reason from correlation to direct causal connection. On the other hand, by correlation we may directly compare the relation between any one trait and various factors. We can find out, for example, whether the association of delinquency with deficiency is closer than the association of delinquency with other factors which it has been suggested are causes of delinquency. Goring's work allows us to compare the correlation of the tendency to be convicted of crime with deficiency and with many other constitutional and environmental factors which have been measured, and thus our attention may at once be directed to that factor which the present evidence indicates as most fundamental. Unless the measurement of the various factors is shown to be seriously faulty or incomplete the outcome should determine our point of view as to the main cause of delinquency, until new evidence is forthcoming. This is the problem of the next section.
C. The Causes of Delinquency.
As we have noted above, the correlation of delinquency with various factors should give us a scientific point of view as to the main causal influence in criminality. Thanks to Dr. Goring this work has recently been carried far. His findings mark a new and higher scientific level in the study of criminology. No data are now available which modify his position in any important regard. I shall, therefore, attempt to give his evidence in the briefest possible manner, hoping that it may lead to a closer reading of his basal investigation.
(a) Constitutional factors.
First comparing a dozen factors in the individual's own constitution which may be measured by the death rates, Goring found the tendency to be convicted of crime was correlated most closely with alcoholism, .39; sexual profligacy (syphilis and aneurism), .31; and epilepsy, .26; while it was found to correlate with intelligence, .66. The closeness of the relationship of defective physique to criminality was expressed by coefficients of .18 and .19. Among the inner factors investigated were many of Lombroso's characteristics of the so-called criminal physiognomy of which so much use is made by phrenologists, such as asymmetries, projection of the chin, complexion, form of the face and features, kind of hair, tattooing, left-handedness, temperament, etc.