Adolescence is the developmental stage between childhood and adulthood;
it generally refers to a period ranging from age 12 or 13 through age 19 or 21.
Although its beginning is often balanced with the beginning of puberty,
adolescence is characterized by psychological and social stages as well as by
biological changes.
Adolescence can be prolonged, brief, or virtually nonexistent, depending
on the type of culture in which it occurs. In societies that are simple, for
example, the transition from childhood to adulthood tends to occur rather
rapidly, and is marked by traditionally prescribed passage rites. to contrast
this, American and European societies the transition period for young people has
been steadily lengthening over the past 100 years, giving rise to an adolescent
subculture. As a result of this prolonged transitional stage a variety of
problems and concerns specifically associated with this age group have developed.
Psychologists single out four areas that especially touch upon adolescent
behavior and development: physiological change and growth; cognitive, or mental
development; identity, or personality formation; and parent-adolescent

Physiological Change:

Between the ages of 9 and 15, almost all young people undergo a rapid
series of physiological changes, known as the adolescent growth spurt. These
hormonal changes include an acceleration in the body\'s growth rate; the
development of pubic hair; the appearance of axillary, or armpit, hair about
two years later. There are changes in the structure and functioning of the
reproductive organs; the mammary glands in girls; and development of the sweat
glands, which often leads to an outbreak of acne. In both sexes, these
physiological changes occur at different times. This period of change can prove
to be very stressful for a pre-teen. For during this stage of life appearance
is very important. An adolescent child who develops very early or extremely
late can take a lot of ridicule from his or her peers. However, the time at
which a girl goes through this stage and a male goes through it are different.
Girls typically begin their growth spurt shortly after age 10. They
tend to reach their peak around the age 12, and tend to finish by age 14. This
spurt occurs almost two years later in boys. Therefore boys go through a
troubling period where girls are taller and heavier than them. This awkward
period occurs from ages ten and one-half to thirteen. Time is not the only
difference in the pubescent period for boys and girls.
In girls, the enlargement of the breasts is usually the first physical
sign of puberty. Actual puberty is marked by the beginning of menstruation, or
menarche. In the United States, 80 percent of all girls reach menarche between
the ages of eleven and one-half and fourteen and one-half, 50 percent between 12
and 14, and 33 percent at or before age 11. The average age at which
menstruation begins for American girls has been dropping about six months every
decade, and today contrasts greatly with the average age of a century ago, which
is between 15 and 17.
Boys typically begin their rapid increase in growth when they reach
about twelve and one-half years of age. They reach their peak slightly after 14,
and slow down by age 16. This period is marked by the enlargement of the testes,
scrotum, and penis; the development of the prostate gland; darkening of the
scrotal skin. The growth of pubic hair and pigmented hair on the legs, arms,
and chest takes place during this period. The enlargement of the larynx,
containing the vocal cords, which leads to a deepening of the voice causes much
stress for a pubescent boy. In this transitional period in his voice tends to

Cognitive Development:

Current views on the mental changes that take place during adolescence
have been affected heavily by the work of the Swiss psychologist Jean Piaget,
who sees the intellectual capability of adolescents as both "qualitatively and
quantitatively superior to that of younger children." According to Piaget and
the developmentalist school of psychology, the thinking capacity of young people
automatically increases in complexity as a function of age. Developmentalists
find distinct differences between younger and older adolescents in ability to
generalize, to handle abstract ideas, to infer appropriate connections between
cause and effect, and to reason logically and consistently.
Whether these changes in cognitive ability are a result of the
developmental stage, as Piaget suggests, or should be considered the result of
accumulating knowledge that allows for new mental and moral perspectives, an
enlarged capacity for making distinctions, and a greater awareness of and
sensitivity to others, is a question that psychologists continually debate.
Behaviorists such as Harvard\'s B. F. Skinner did not believe intellectual
development could be divided