the child, usually the mother, or some other member of the family, or the nurse.
In the next stage, during adolescence or perhaps later, in adulthood, when the psycho-erotic life of the individual has suitably developed, it is again transferred to a person outside the family group—constituting what is familiarly known as falling in love.
Close students of child psychology have pointed out the fact that the infant enjoys in the taking of food an erotic (sexual) pleasure which it frequently seeks to obtain throughout childhood independent of taking nourishment. Dr. G. Stanley Hall's comment quoted above also alludes to this.
From this tendency, the habit of sucking the thumb or fingers may be formed, with rhythmic movements which grow into a fixed childish fault. Often there is associated with this "pleasure-sucking" a rubbing of sensitive parts of the body, the breast, the external genitals, etc. In this way many children automatically proceed from sucking to masturbation.
It is observed, too, that pleasure-sucking is connected with an entire exhaustion of attention and leads to sleep. The same principle holds true throughout life, i. e., the release of sexual tension—sex gratification in the adult—is conducive to repose and sleep. There is a medical axiom to the effect that sexual satisfaction is the best sedative.
From the adult standpoint many nervous insomnias are traced to lack of sexual gratification. It is also known that unscrupulous nurses calm crying children to sleep by stroking their genitals.
It is true that not all children suck their thumbs. It may be assumed that it is found primarily in children in whom
