“Thus, though our delinquents are not as capable as their sisters, many of them from congested districts, who in other ways are proving themselves ambitious [the group from night classes,] yet they are no less equipped intellectually than others who are earning a livelihood and caring for themselves without coming in conflict with the law in the least. Whatever their mental status might be, measured by other means, the fact remains that there is no necessary correlation between their immoral or criminal tendencies and their intellectual ability and that others, no more endowed than they, are fighting life's battles without manifesting the same immoral or criminal tendencies” (112, p. 43).
What portion of these moral household servants of equal ability with the delinquents may later fall under temptation, we, of course, cannot say. Neither can we say that any of the delinquents would test deficient, since we do not know the border lines of deficiency with the tests which were used. The conclusion, however, is clear that, if corresponding grades of intellect may be delinquent or not at maturity, we must be cautious in assuming that the lowest grades of intellects would all become delinquent if not under supervision.
What chances we are running by allowing feeble-minded individuals to be abroad might be determined if we could find out the probability of tested deficients becoming delinquent. This question cannot be answered by showing for a single year or a period of years that crimes are relatively more common among the defective classes, although such figures give some impression of the danger of deficiency to the community.
Kinberg, for example, calculates that in Sweden during the years 1901-1907 murder was relatively 200 times as common as among those not in institutions, but lacking criminal responsibility through insanity or deficiency, as among those who were responsible, arson was 72.5 as common, manslaughter 12.63 times, other injuries to property than arson 6.55, rape 6.1 times, infanticide 4.59 times, larceny 0.99 times, and fraud 0.26 times ([132]). The data were based upon the reports of the Royal College of Health which makes the diagnosis as to criminal responsibility that is required for all cases in which this question arises. Such examinations, it is estimated, miss at least 15% of the deficient criminals.
Goring gives a table which shows what crimes are most likely to be committed by deficients. He found that 10% of the convicts in England and Wales were definitely treated in prison as deficient, and he estimated that 0.5% of the non-criminal population were equally deficient. His table is based upon the tabulation of 8,290 crimes past and present of 948 English convicts (Fig. XXXIX, p. 258). It is given below:
TABLE XVII.
Goring's Data as to the Percentage of Mental Defectives Among Men Convicted of Various Offenses. (948 Convicts)
| Firing of stack | 52.9% |
| Wilful damage, including maiming of animals | 22.2 |
| Arson | 16.7 |
| Rape (child) | 15.8 |
| Robbery with violence | 15.6 |
| Unnatural (sexual) offenses | 14.3 |
| Blackmail | 14.3 |
| Fraud | 12.8 |
| Stealing (and poaching) | 11.2 |
| Burglary | 10.0 |
| Murder and murderous intent | 9.5 |
| Rape (adult) | 6.7 |
| Receiving | 5.1 |
| Manslaughter | 5.0 |
| Coining | 3.3 |
| Wounding, intent to wound, striking superior officer | 2.9 |
| Embezzlement, forgery, fraudulence as trustee, bigamy, performing illegal surgical operation | 0.0 |
| General population | 0.5 |
Another table from Goring shows which groups of crime are most likely to be committed by the deficients compared with the frequency of that type of crime in the general population. It is reproduced in part below.
TABLE XVIII.