The gradual growth of infanticide can easily be traced to natural causes. We can presume that some form of permanent mating existed in man's immediate ancestors, and that marriage is immeasurably older than man himself, for our first glimpses of man reveal evidences of a family. We can also presume that in these primitive families, the causes of death were so numerous that there must have been fifteen to twenty children to each family, if two or three were to reach maturity and raise families of their own. As soon as man attained such a mastery over his enemies as to raise more children than the supposed two or three out of twenty, he was at once overburdened with children, as he could not limit the production.
The murder of infants, of course, must have suggested itself to primitive women in times of famines - and we find as a matter of fact that it was an universal custom, the little one being simply put out to die of exposure - rarely was strangulation the custom except when the mother died. The ancient Peruvians, for instance, strangled an infant with a string of hair cut from its dead mother's head, and buried the two together. It was more humane than to let the little one suffer to the inevitable death - for no one could raise it except its own mother. Consequently, infanticide is an universal savage custom, a necessity of our own ancestors and still practiced in every low civilization. Throughout Polynesia it still survives, though more or less checked by civilized influences. It is common throughout Asia and Africa, and even Eskimos resprt to it in times of famines. It was common even in high civilizations. It was compulsory in Sparta, and exposure is clearly stated to have been the practice among the Jews at the late date of the writing of Ezekiel (Chapter xvi (The Myth Of Acclimatization. Tropical Infections)). In China it is almost universal, for the civilization is stationary, and there is no increase of food production, so that the death rate must equal the birth rate. At a very low estimate there are 15,000,000 births yearly in China, of which fully 3,000,000 or perhaps 6,000,000 are destroyed. It is ridiculous for missionaries to buy up and save a few score of these - a mere drop in the bucket - and every life saved means one more to starve to death in future famines. The native Australians even yet are compelled to kill a certain percentage of children, as well as mutilate the husbands, after the birth of the second or third child, either by castration or by causing artificial hypospadias. It is said that the British precipitated the great Indian mutiny by forbidding infanticide at Oude. There is considerable evidence that lower animals occasionally kill their young - instinctively, of course. It has never been studied in detail, but it must be done in stress, for the same purpose that savage man does it.
In every modern civilization conducted by the higher races, there are descendants of the lower conquered types of Europe - real survivors of primitive man, or neolithic man or even paleolithic man. These hold to old ideas and customs with remarkable persistence. It is not at all strange, therefore, that we are regaled in the press with so many accounts of infant slaughter. Even the cool way in which some people accept the death of infants is a survival of the time when one less mouth to feed was an advantage. The great majority of modern civilized women are said to believe that it is not murder to kill an unborn infant in the first months of its existence, though not later, and the law makes this distinction.