All women possess originally, from early childhood to death, some interest in human babies, and a responsiveness to the instinctive looks, calls, gestures and cries of infancy and childhood, being satisfied by childish gurglings, smiles and affectionate gestures, and moved to instinctive comforting acts by childish signs of pain, grief and misery. Brutal habits may destroy, or competing habits overgrow, or the lack of exercise weaken, these tendencies, but they are none the less as original as any fact in human nature.[13] This relation is of course useful and necessary since the child is helpless throughout a period of years and would not live unless the mother were impelled to give it her devotion. This attitude is present in the father of the child also but is weaker, less demonstrative, and called out more gradually. In addition, the desire for response between the two sexes in connection with mating is very powerful. An ardent courtship is full of assurances and appeals for reassurance. Marriage and a home involve response but with more settled habits, more routine work, less of new experience. Jealousy is an expression of fear that the response is directed elsewhere. The flirt is one who seeks new experience through the provocation of response from many quarters. In some natures this wish, both to receive and to give response, is out of proportion to the other wishes, “over-determined”, so to speak, and interferes with a normal organization of life. And the fixation may be either on a child or a member of either sex. The general situation is the same in the two cases following. 11. I am the unhappy mother of a dear little son, eight years old. You ask the cause of my unhappiness? I ought to be happy with such a dear treasure? But the answer is, I love my child too much. My love to my son is so great, so immeasurably deep, that I myself am worthless. My own person has not a trace of worth for me. I am as it were dead to all and everything. My thoughts by day and by night are turned toward my child. I see nothing in the world except my beloved child. Nothing exists for me except him. Every one of my thoughts, every desire and wish that awakens in me, turns around the child of my heart. I am nothing. I do not live, I do not exist. I forget myself as I forget all and everything in the world. I go around the whole day without eating and feel no hunger. I forget that I must eat. I go around often a whole day in my nightclothes because I forget that I have to dress. With soul and body, with mind and spirit I am wrapt up in my child. I have no thought for myself at all.