468 Adolescent Health
through these phases lags behind that of girls, just as with
physical development.
One major focus during early adolescenceis the desire for
increased independence from family, combined with a rapid
rise in the importance of peers. Need for conformity with
peers peaks in preadolescence and early adolescence, fol-
lowed by a gradual decline through late adolescence. Such
conformity includes dress, hairstyle, music, and language.
Abrupt changes in these areas can startle parents as they see
their child turn into someone they barely recognize. Yet this
new orientation toward peers (versus family) does not repre-
sent a total transformation. Young teenagers certainly re-
spond to peer in”uence, especially that of same-sex peers, in
areas where they (probably correctly) perceive that their par-
ents will not be knowledgeable about what constitutes •coolŽ
clothing, •inŽ music, and appropriate patterns of interaction
with same- and opposite-sex peers. However, they typically
respond to parental in”uence regarding educational plans and
aspirations, moral and social values, and understanding the
adult world. For example, one large-scale study of two
groups of boys (blue-collar versus upper middle class) in
Chicago revealed that each group•s values and expectations
were more similar to those of their parents than they were to
their peers in the other socioeconomic group (Youniss &
Smollar, 1989).
Another major focus during early adolescence is body
image, hardly surprising given the massive physical changes
that occur during this time. Young teenagers evidence intense
interest in and often dissatisfaction with speci“c parts of their
bodies. A classic study (Douvan & Adelson, 1966) asked sev-
enth graders what one aspect of themselves or their lives they
would change if they could, and 59% selected a speci“c body
part. This suggests that disease, illness, trauma, or even devi-
ations in normal development, which have obvious physical
consequences, will pose even more psychological challenges
for young adolescents than for older teenagers. Another
implication is that it is particularly important for young
adolescents to receive detailed feedback during routine phys-
ical examinations, reassuring them that their physical devel-
opment is proceeding normally and encouraging them to
express concerns and questions that almost certainly are
present but which they often are too embarrassed to raise
spontaneously.
The developmental focus shifts in mid-adolescencebe-
cause most teenagers begin to date between the ages of 13 to
15, with the onset of dating being in”uenced by gender and
social status. With increasing interaction with the opposite
sex, teenagers concentrate on sexual identity, dating behav-
ior, communication skills, and rules for interaction with peers
of both sexes. These early relationships are often brief and
shallow, with physical appearance and skills playing a major
role in choice of partner.
The transition to abstract thought, which has typically
occurred during early adolescence, paves the way for new
cognitive activity in mid-adolescence. It is generally during
this time that adolescents display increased interest in ab-
stract concepts and even thinking per se; one teenager in-
formed the author that •I•m thinking about the fact that I•m
thinking about the fact that I•m thinking.Ž Morality, justice,
and fairness become a focus, both regarding teenagers them-
selves (and those who inhabit their world) and society in gen-
eral. Teenagers in mid-adolescence thus often devote time
and thought to rules and laws (school and national), social
structure, and systems of government.
To address the “rst major task of late adolescence,
teenagers begin to focus seriously on career plans, which
often are unstable until the age of 16. By 17, most adoles-
cents have at least established an initial direction for their
future career and made plans to implement appropriate edu-
cation and training to achieve these goals. However, com-
pleting such training and alteration in career goals often
continues throughout young adulthood.
The second major task of late adolescence is development
of intimacy in personal relationships, especially with an
opposite-sex partner. Older teenagers focus on different as-
pects of dating, moving beyond external appearance, as they
develop true sharing and caring. Establishing a personal sup-
port system of friends, partner, and meaningful adults (e.g.,
teacher or boss) is as important as economics in allowing
teenagers to function separately from their families. The
developmental task of independence from family is thus
frequently not fully completed until well after adolescence.Interaction of Physical and Psychosocial DevelopmentTiming of PubertyThe onset of puberty occurs at a mean age of 11.2 years for
girls and 11.6 years for boys with evident physical changes at
mean ages of 12.2 years and 12.9 years. Because of the
tremendous variability present among normally developing
adolescents, however, visual evidence of puberty (Tanner
Stage 3) can range from age 10.1 to 14.3 (girls) and 10.8 to 15
(boys). These age ranges are within two standard deviations
from the mean and considered medically normal. Extreme
delay or precocity (2 standard deviations above or below the
mean) requires medical evaluation to determine potential hy-
pothalamic, pituitary, or gonadal dysfunction; undiagnosed
chronic illness; or chromosomal abnormality (see •Special
ConditionsŽ in a following section). However, even teenagers