Some aspects of this development are more easily perceived than others, like the puberty (from Latin pubertate), for example, that corresponds basically to the initial period of the adolescence, characterized by the process of maturation of the physical and sexual characteristics of the human being.

Among boys the change begins to occur about 12/13 years (with variations for more or less). The main alteration is the appearance of hair in the genital area. Besides, the voice goes under a modulation (low-pitched-high-pitched), tending to be thicker; the stature increases; the muscles enlarge; hair begins to appear o­n the face and underneath the armpits; the smell changes; the hair changes; the skin changes (appearance of acne and spines). In addition, the testicles grow, the penis gains volume and the boy gets to ejaculate for the first time. Ejaculation marks the maturation of the male body, which begins to be ready for the reproductive life, in theory at least. All this transformation is determined by the increase of the amount of the male hormone known as Testosterone, produced by the testicles.

The same process occurs with the girls. Around 10 years old (roughly), there comes the appearance of the mammary sprouts (small buttons below the nipples). From there o­n, girls begin to gain stature, the body shape gets rounded, and hair in the armpits begins to appear as well as in the genital region. The breasts gain volume. Hormonal changes lead to the maturation of the ovules and to the preparation of the uterus to receive them. Menstruation comes to show that, from the physical point of view, the girl-woman is mature and able to give birth to a son, at least in theory. All these alterations are caused by an increase in the amount of the feminine hormone known as Estrogen produced by the ovaries.

The society expects from the adolescent a mature position, which he/she is unable to give. This leaves room to frustrations, sense of inferiority and high levels of physical and emotional demands.

In terms of the unconscious level, all this process of physical changes implies in a build up of a sort of grief for the loss of the identity and infantile image. When the adolescent doesn’t come to terms at all or incompletely comes o­n top of such grief, this will certainly emerge under the guise of obsessions, which can be easily identified by the behavior of such young person. If such obsessions aren’t properly treated in psychotherapy could follow the adolescent for the rest of his/her life as a part of his/her personality.