The conception of a criminal diathesis does not stop merely with the notion that there is an inborn predisposition to crime. It considers further that offenses do not occur except under the stimulus of certain situations, even if such stimuli may be even more common than the tubercle-bacillus. The important question which it now puts to science is, “How much may the actual outbreak of delinquency be reduced with better methods of social prophylaxis?” Even if, “the chief tasks of social hygiene” are the “struggle against alcohol and against poor economic conditions,” as Aschaffenburg believes (_68_, p. 228), the chief emphasis from the best scientific work still seems to be that the problems of alcoholism, poverty and crime are more closely related to internal than to the external conditions which have thus far been measured. Guarding against the propagation of mental deficiency thus seems to be the most direct and hopeful method of attack, while the removal of infecting temptations, and training for greater resistance, should receive hearty, albeit subordinate emphasis. ----- Footnote 33: See the next section for the significance of these coefficients of correlation. CHAPTER XII. SUMMARY AND SUGGESTIONS 1. In our attempt to interpret the volume of results concerning tested delinquents, we have accepted the common conception that the feeble-minded are those who, through lack of mental development, are _social deficients_. They cannot survive in society without supervision. In the words of the English Mental Deficiency Act, “they require care, supervision, and control for their own protection or for the protection of others.” Our present scales of development tests do not detect those deficients whose failure is not directly due to intellectual incapacity. We have called those not detected by tests “purely conative cases,” to distinguish them from the tested deficients, who were said to be “intellectually deficient.” These conative cases would not be feeble-minded except for their incapacity for prolonged acts of will. Deficiency thus specialized in volition is so unusual, however, that the study of tested deficients gives us a useful picture of the problem of feeble-mindedness. To get a general view of the relation of deficiency to delinquency we determined conservative borderlines with the Binet scale and then reinterpreted on a common conservative basis the results obtained in more than a score of investigations covering thousands of objectively selected delinquents who had been tested. This has enabled us very largely to remove the question of the frequency of deficient delinquents from the realm of subjective opinion. We may now be certain that under present conditions the problem of deficiency is most pressing in institutions for female offenders. The evidence also points to the greater frequency of deficiency among prostitutes and repeaters, rather than among ordinary juvenile delinquents.