Just as in the case of children the hostile emotions towards the parents that arise from jealousy are liable to be powerfully reinforced by those due to more general interference with the child's desires, so too in the case of the parents, any ill-feelings that they may bear towards their children as a result of jealousy are likely to be complicated by other causes of hostility. If it be to some extent inevitable that children should come to regard their parents as obstacles to the full attainment of their own desires and as unwelcome causes of interference with their most cherished activities, parents have at least equal reason to complain similarly of their children. The responsibility, the effort, the anxiety, involved in rearing children, diminish very considerably the time and energy available for more directly personal occupations and enjoyments. To some extent the individual inevitably sacrifices himself in becoming a parent, in accordance with the general biological law which Spencer has designated the antagonism between individuation and genesis; and this sacrifice of personal comforts, pleasures, satisfactions and ambitions does not as a rule take place without some degree of resentment being felt against those whose existence necessitates the sacrifice. Even where--owing to robust health, abundant energy, ample means, state relief or other circumstances--children demand but little sacrifice of the major aims and occupations of life, the very considerable difference between the points of view of children and those of adults and the largely incompatible nature of the conditions and activities that appeal to their respective minds tend to make the constant presence of children, especially within the confines of a small home, inevitably to some extent a cause of annoyance to the parents. As Bernard Shaw[202] so well points out, children are indeed to some extent necessarily and unavoidably a nuisance to grown-up persons; with their illregulated and impulsive energy and their disregard of the habits and conventions to which their seniors have become accustomed, they constitute an ever present menace to the comfort and tranquillity of adult life--a menace from which even the most devoted parent must sometimes wish that he could free himself. [Sidenote: Their influence on the mother] The mother, owing to the greater demands which children make upon her time and health and energy is perhaps that one of the parents to experience most keenly such hostile feelings, though the existence of a strong counter-impulse towards maternal love will often insure repression of these feelings into the unconscious; so that it usually requires a process of analysis to reveal the often strong resentment that a mother may entertain towards the child who so seriously interferes with her more directly individual needs and aspirations[203]. [Sidenote: On the father]