Puberty is one of the three major stages of physiological sexual development, along with prenatal sexual differentiation and menopause. Puberty marks the transition from sexual immaturity to maturity and the start of reproductive ability. In Chapters 4 and 5, we discussed the physiological and hormonal changes that accompany puberty, so here we will review only those physical changes that have an effect on the nature of adolescent sexuality.
Puberty begins anywhere between the ages of 8 and 13 in most girls and 9 and 14 in most boys. In fact, the age of puberty has been steadily declining, especially among girls, probably due to better nutrition during childhood. American girls reach menarche at the mean age of 12 (Steiner et al., 2003), and boys experience first semenarche at about the age of 13 (Stein & Reiser, 1994). In other countries, the age at which children reach puberty may differ. A study in Israel, for example, found the age of semenarche of about 14 (Reiter, 1986). Girls’ maturation is, in general, about D/2 to 2 years ahead of boys (Gemelli, 1996).
Parents are often shocked at the extreme changes that puberty can bring; a boy can grow up to 5 or 6 inches in less than a year and develop pubic hair, a lower voice, and a more decidedly adult physique. Girls begin to develop breasts, pubic hair, and an enlargement of the genitals. Though we tend to concentrate on the development of the sexual organs, biological changes take place in virtually every system of the body and include changes in cardiovascular status, energy levels, sexual desire, mood, and personality characteristics (Hamburg, 1986). If those changes are difficult for a parent to cope with, imagine how much more difficult it is for the person going through it!
The physiological changes of puberty almost seem cruel. At the time when attractiveness to potential sexual partners begins to become important, the body starts growing in disproportionate ways; fat can accumulate before muscles mature, feet can grow before the legs catch up, the nose may be the first part of the face to begin its growth spurt, and one side of the body may grow faster than the other (Diamond & Diamond, 1986). Add acne, a voice that squeaks at unexpected moments, and unfamiliarity with limbs that have suddenly grown much longer than one is accustomed to, and it is no wonder that adolescence is often a time of awkwardness and discomfort. Fortunately, the rest of the body soon catches up, so the awkward phase does not last too long.
Maturing early or late can also be awkward for boys or girls. Because girls’ growth spurts happen earlier than boys’, there is a period when girls will be at least equal in height and often taller than boys; this reversal of the cultural expectation of male height often causes both sexes to be embarrassed at dances. Being the last boy (or the first) in the locker room to develop pubic hair and have the penis develop can be a humiliating experience that many remember well into adulthood. Similarly, girls who are the first or last to develop breasts often suffer the cruel taunts of classmates, though the messages can be mixed. It may be this combination of beginning of sexual exploration, changing bodies, and peer pressure that results in the average adolescent having a negative body image (Brumberg, 1997).