11. Sex Incompatibility.--There comes under this heading a wide range of causative factors which play an important part in marital discord. Some of them are better understood by the social worker than was formerly the case; but many of them are obscure even to the practitioner of mental medicine, to whom their results come daily. Distasteful as the task may be, the social worker should familiarize herself, through reading or through instruction by a qualified physician, in the commoner forms of these maladjustments. This is not urged because it is part of the social worker's task to make detailed inquiry into such matters or to pass judgment upon them, but because they often clamor for attention and need to be recognized by the first responsible person to whose notice they are brought. Unless she knows, for instance, what constitutes excess in sex relations, a worker may misunderstand the situation described to her and condemn a man for being a selfish brute, when the trouble is really sexual anaesthesia in the wife. It is well known that this single cause operates disastrously to disrupt many marriages or else to render them insupportable. The warning should be added, however--and it cannot be added too emphatically--that the social worker must scrupulously refrain from making diagnoses in these cases, even tentatively; she must refer such data as come to her either to the general practitioner or to the psychiatrist, selecting one or the other as the symptoms presented may indicate. Less well understood by the lay worker are actual maladjustments, both physical and mental (or spiritual), which prevent the complete satisfaction of one or both. Some of these are curable by medical care, others by instruction and education. This instruction should be given, needless to say, by the physician and not by the case worker. If uncorrected such maladjustments are apt to result in marital shipwreck. No attempt can be made here to discuss actual sex perversions in their relation to desertion. Their effect is obvious; and the social worker should be sufficiently well informed, not only from a few standard books on the subject,[13] but from a knowledge of the phrases which are used in the tenements, to understand them, so that significant symptoms are not overlooked. So intimately are sex difficulties connected with the neuroses that the lay social worker should consult the psychiatrist freely wherever one is available, before attempting to deal with them. 12. Vicious Habits.--Sexual immorality, through its degenerative effect on personality and the lowered ideals of marriage it induces, has a real effect in bringing about desertion. The "other man" and the "other woman" type of desertion, however, is often itself only a consequence of a previously existing state of temperamental or sexual incompatibility. If these underlying causes can be attacked and changed such a desertion may be "repairable."