Deficiency and Delinquency: An Interpretation of Mental Testing

by James Burt Miner

“Our table 177, above, starting with crimes of fraud, passes to stealing and burglary—professional crimes, where the influence of criminal contagion should be the most intense; and then progressively to violence, arson and sexual offenses, in which last it is difficult to understand how the influence of example could have any effect at all. We can understand the influence of parental training in the original moulding of a professional burglar or thief, and, to a certain extent, it is conceivable that the constant spectacle of the lack of control in parents might lead their offspring to emulate them in acts of unlawful violence. But, that parental example could play any part of importance in the perpetration by their offspring of crimes such as arson and wilful damage to property, and, particularly, of sexual offenses, is not reasonably to be supposed. As seen in the above table, 177, the parental correlation for sexual crimes, and crimes for wilful damage to property is from .45 to .5; for stealing, it is from .48 to .58. We would assume then, from this evidence, that the tendency of the inherited factor in criminality is from .45 to .5, and the intensity of criminal contagion is anything between .05 and .1” (20, p. 367).

Other evidence as to the relative influence of heredity and training, which Goring suggests, is in connection with the difference in influence of the two parents. If the contagion were from either the mother or father alone, the difference in resemblance to that parent and the other might indicate the strength of the contagion. The difference amounts to about .05. This again, in his opinion, gives some idea of the relative importance of nature and nurture within the family. The measure would not be complete unless the hereditary tendency to resemble mother and father were equal and the contagion were all from one parent.

Husbands and wives tend strongly to resemble each other in crime, the correlation being .6378. This resemblance is of course not due to heredity. Goring believes that it is not due to contagion and argues that besides the subjective tendency for the criminals to associate together, there is here a large element of conscious choice of a mate among the criminal classes, especially as the criminal woman shows the tendency most clearly and would not be able easily to get a non-criminal husband.

This work of Goring illustrates how an important beginning has been made in applying the correlation method to objective records, in order to weigh the relative importance of hereditary and environmental sources of crime. Perhaps its most important support is the close agreement between his conclusions as to the importance of the native diathesis of criminality and other studies by the biometric school as to the family tendencies in physical traits such as stature, eye color, tuberculosis, insanity, and deafness. These all tend to show a correlation between parents and children or brothers and sisters of about .5 as compared with relations to environmental factors which tend to be less than .1 ([165]).

(d) The criminal diathesis.

If one accepts the point of view that the cause of crime is to be considered analogous to that of pulmonary tuberculosis, his understanding of the etiology of crime gains immensely. The old question of whether the criminal is born or made is answered, “both.” But the emphasis from our present data is on the inborn tendencies. Moreover, being born with the criminal diathesis does not mean that a person is predestined to commit crime, but that he is more likely than his neighbor to be infected by the contagion of delinquency. We have only to catch the trend of recent scientific research to extend our vision further. The criminal does not lack a simple unit character which would otherwise make him whole as some of the disciples of Mendel seem to argue. Neither is the criminal diathesis a simple instinctive tendency like the tendency to make a specific response to a specific stimulus, e. g., to wink when an object approaches the eye; the criminal is not charged with a specific propensity to commit murder or to steal. The safety of those who are more susceptible lies in keeping away from the contagion of bad example and temptations to fall, toward which he is generally less resistant than others. Specific training in strengthening and guarding his weakest spots may in time build up a resistance to temptations, the amount of which we cannot yet measure. His hope lies in the recognition of his weakness and the adjustment of his living so that his whole organism may support the breach in his make-up during the struggle with himself and with society.

In this complex diathesis which means greater susceptibility to temptations, there is little doubt that mental deficiency is the main factor. Aschaffenburg has well expressed one effect of this particular causal factor: “The weak-minded are generally children of the moment.... The lessons of experience, which serve normal persons as a guide, in later events, soon fade, be cause they cannot be fitted into the existing condition of the ideas. The inability to understand, much less to form general points of view, is the direct result of mental weakness” (20, p. 180). Lacking the ability to organize their experience, fixed punishments have little restraining influence. Only prolonged training and supervision can save them from being the victims of the moment. Even the large majority above the grade of ability which would justify indefinite supervision still show their stupidity in the offenses they commit. Goring gives an instance of a watch repairer who was legally punished nine times for pawning watches entrusted to him to repair. Who would doubt that native stupidity is an important cause of the recidivism which is so common a criticism of our present forms of legal discipline? It is stated, for example, that 10,000 of those convicted in one year in England had been convicted more than twenty times before (165, p. 59). Even with school punishments the same association of bad conduct and stupidity holds. Kemsies has shown, as quoted by Terman, that the 16% ranking lowest in a group of pupils received 80% of the punishments, while the brightest third received almost none ([194]).

That the criminal diathesis is not limited to mental deficiency is demonstrated by Goring's results. He shows its smaller correlation with deficient physical size, alcoholism and suicidal tendency with such pathological conditions as insanity and epilepsy, independent of their relations to mental deficiency. In this connection Gruhle's opinion that the hereditary tendency to crime was greater among his non-defective families may be borne in mind.

That mental ability, and especially mental deficiency, is primarily a question of inherited capacity rather than training, is now indicated by a number of fundamental objective studies of the correlation of abilities within the family, which have been analyzed to show the relative influence of inborn and external factors. Among these studies Thorndike's investigation of the tested abilities of twins compared with brothers and sisters in the same family is the most objective, and is very convincing ([199]). He has also summarized the evidence so well that it is not necessary to go into the question here ([198]). One of the most important facts is that equal practise under the same conditions increases the difference between individuals rather than makes them more alike. The work of the English biometricians appearing in Biometrika and the monographs from the Eugenics Laboratory is the most important in this field, and cannot be summarized here. It includes family resemblance in both pathological and healthy mental traits ([126]).

As compared with these studies the attempt to show that feeble-mindedness is inherited, because many of those in institutions for the feeble-minded are from families showing mental taints, lacks cogency, since we are still uninformed as to what portion of the offspring of parents with and without deficient minds are deficient. Even if 85% of the children in institutions for the feeble-minded have tainted parents this does not mean that we know what percentage of deficient parents have deficient offspring. It is this latter fact that we must know in order to predict the danger of defective offspring from deficient parents. From what we know about the correlation of parents and offspring in mental ability, it is clear that the more deficient are the parents, the more likely it is that their offspring are deficient. Children of morons are, therefore, not so likely to be deficient as are children of parents with lower grades of ability. From the eugenic point of view, it is, therefore, most important first to protect society from propagation by the lowest grades of deficients, provided that all grades of deficients are equally likely to have children when left unrestrained in society. Since mental and moral qualities are probably correlated positively, the same emphasis would be placed on first isolating the lowest grades in order to reduce inheritance of criminality. The eugenic emphasis waits, however, on the discovery whether the greater tendency for the lowest types to be produced by the lowest types is overbalanced by any tendency of deficients or delinquents of lower degrees to be less productive when unrestrained in society.