Being a late acquisition of the race and less firmly ingrained, the social instinct is not well established in all individuals. Some have it sufficiently strong to exercise of their own accord the necessary inhibitions of other instincts. Experience has shown that others, either through a lack or through a wrong cultivation of it, can not or will not do so unaided. For the latter, society has instituted certain conventions and the criminal law whereby through a system of restraints and punishments such an individual is held in check either by actual physical restraint of his property or person or through the powerfully inhibitive factors of shame or fear. Man as a normal member of society must constantly take heed of the physical, intellectual or moral danger the exercise of a given feeling, action or procedure on his part will bring to humanity, and govern himself accordingly. But it is in just these very inhibitions that mental defectives are lacking. They are almost invariably anti-social types because they are unable to establish the personal abstentions which are necessary for the good of the community. While in the individual of innate normal mentality anti-social traits may have developed because of improper training or surroundings, in mentally defective types some factor or factors necessary to normality have been left out of their make-up and as a result they are often wholly lacking in social instincts or have these so feebly developed that education and exhortations toward social ideals are fruitless. We can not appeal successfully if there is nothing to appeal to; we can not develop something out of nothing. =The High-Grade Moron a Difficult Problem.--=One great difficulty in identifying the high-grade morons who are a bountiful source of our criminals is our almost universal failure to recognize that a memory test alone is not sufficient to determine the mental responsibility of an individual. Not only memory, but judgment, will-power and perhaps, also, to a lesser degree, the powers of attention and concentration are all indispensable elements in the make-up of a normal individual. There are cases on record of imbeciles with prodigious memories, yet hopelessly incapable of caring for themselves or of respecting the rights of others. In fact certain types of morons, usually cunning, often prepossessing and superficially clever, are characterized by good memories and will _moralize_ volubly, although their wills are too weak to inhibit impulses when they face temptation. It is obvious that just in proportion as the intelligence of the high-grade degenerate approaches normality and yet remains abnormal, the more dangerous he may become to society. =Degenerate Strains.--=A number of family records are now available which show convincing evidence of the hereditary nature of a degeneracy which finds expression in pauperism, immorality and crime.