It is obvious that alcoholism—from which almost all habitual criminals suffer—must favour the failure of inhibition. The psychology of the criminal is, as a rule, so interpermeated with the characteristics of alcoholism that it is often necessary to grope back into the childhood of the individual in order to ascertain the original lineaments of his character.[31] The parasitism of the existence of the criminal is mainly an outcome of economic conditions, and not an elementary feature of crime. In this respect, criminality closely resembles prostitution, which, at least in the modern large town, is through and through a product of parasitic luxury. Passing on now to consider the pressing question of the causal connection between the psychical and the physical fundamental characteristics of the criminal, we find that it is not possible from the physical characters to deduce with certainty a corresponding development of feeling. But it may well be that both series of phenomena result from a common cause—viz., the arrest of development at a not completely human stage of evolution. This conception of Lombroso’s—which I myself regard as correct—is readily comprehensible by every evolutionist, for the evolutionist must assume the inheritance of social feelings, and therewith also the inheritance of the organic substratum of these feelings. In accordance with the modern standpoint of physiological psychology, we have every reason to regard the vasomotor nervous system as a part, at least, of the organic substratum in which, alike in the individual and in the race, the development of feeling runs its course. A very strong reason for believing that the predisposition to crime is based upon a definite congenital tendency is to be found in the fact that the inheritance of criminal tendencies is manifested also in cases in which neither environment, nor education, nor example, suffice to account for the phenomenon. A very large mass of materials has been collected bearing upon this thesis, a part of which will be found in Lombroso’s own writings, a part in Ribot’s celebrated work on “Heredity,” and a part in my own “Natural History of the Criminal.” The most frequent manifestations of criminal heredity take the form of a tendency to fraud, to arson, and to sexual crime. Cruelty, also, is very frequently inherited; and this tendency sometimes finds expression in the desire, as a hospital nurse, to see as many operations as possible, or, at least, to witness as many confinements as possible. The inheritance of criminal tendencies is also shown by the frequency of criminal acts in children; and at the present day, in the enormous increase of youthful criminality, the primitive and original character of criminal tendencies is most clearly manifested.