Most of the inmates of prisons convicted of sex crimes are the poor and wretched and the plainly defective. Nature, in her determination to preserve the species, has planted sex hunger very deep in the constitution of man. The fact that it is necessary for the preservation of life, and that Nature is always eliminating those whose sex hunger is not strong enough to preserve the race, has overweighted man and perhaps all animal life with this hunger. At least it has endowed many men with instincts too powerful for the conventions and the laws that hedge him about.

Rape is almost always the crime of the poor, the hardworking, the uneducated and the abnormal. In the man of this type sex hunger is strong; he has little money, generally no family; he is poorly fed and clothed and possesses few if any attractions. He may be a sailor away from women and their society for months, or in some other remote occupation making his means of gratifying this hunger just as impossible. There is no opportunity for him except the one he adopts. It is a question of gratifying this deep and primal instinct as against the weakness of his mentality and the few barriers that a meagre education and picked-up habits can furnish; and when the instinct overbalances he is lost.

Incest, which is peculiarly the crime of the weak, the wretched and the poor, has a somewhat different origin. Westermarck in his “History of Human Marriage” shows that in the early tribe there was no inhibition against the marriage of blood relations; that the restriction then was against the members of the tribe that used one tent; these might or might not be blood relations. The traditions and folk-ways against the marriage of close relations grew from the familiarity that came from the living together of brother and sister, for instance, in one home. This feeling gradually worked itself into custom and habit and from that into folk-ways and laws. Sometimes we read accounts of the marriage of a man and woman who found, after years had gone by, that they were brother and sister who had been separated in infancy and grew up without knowledge of their relation to each other. Whether Nature forbids the marriage of relatives by preventing offspring or by producing imperfect offspring is a doubtful question. Certain communities in Europe have lived together so long that all are related and still they seem to thrive. Considering the general custom and feeling on the subject, however, the man and woman who know that they are closely related and who marry are different and weaker than the others; and this may show in their offspring. Although the subnormal may have no such feeling, they are judged by the traditions and customs of the normal and on that judgment are sent to prison.

Many sex crimes are charged to children in the adolescent age; children who have no knowledge of sex and its development and are helpless in the strength of their newly-discovered feelings. This class of offenders is almost always the inferior and the poor who are moved by strong instincts which they have not the natural feeling, the strength, the education, nor the desire to withstand.

While most crimes against persons are not directly due to economic causes, still the indirect effect of property is generally present in these crimes as well as others. The fact that the poor and defective are generally the subjects of prosecution and conviction in these offences shows how closely economic conditions are related to all crimes.

Other criminal statutes are of more modern date, and as a rule involve not much more than adultery, except in regard to the age of the girl offender, which is generally placed below eighteen. Still the sex age of neither boys nor girls can be fixed by a calendar. It depends really upon development, which is not the same with all people or in all environments. Many girls of sixteen are more mature and have more experience of life than others of twenty. Most laws provide that below sixteen one cannot give consent and that a sexual act is then rape. It is doubtful if there should be any intermediate age between sixteen and eighteen, where an act is not rape but still a minor offence.