Development across the Life Span 339or the uterus) and secondary sex characteristics (changes in the body such as the development
of breasts and body hair) that occur in the body as sexual development reaches its peak.
to Learning Objective 10.1. Puberty occurs as the result of a complex series of glandu-
lar activities, stimulated by the “master gland” or the pituitary gland, when the proper geneti-
cally determined age is reached. The thyroid gland increases the rate of growth, and the adrenal
glands and sex glands stimulate the growth of characteristics such as body hair, muscle tissue in
males, and the menstrual cycle in girls, for example (Grumbach & Kaplan, 1990; Grumbach &
Styne, 1998). Puberty often begins about 2 years after the beginning of the growth spurt, the
rapid period of growth that takes place at around age 10 for girls and around age 12 for boys.
In addition to an increase in height, physical characteristics related to being male or
female undergo rapid and dramatic change. In fact, the rate of growth and development in
puberty approaches that of development in the womb. to Learning Objective 10.1.
After about 4 years, the changes of puberty are relatively complete. The develop-
ment of the brain, however, continues well into the early 20s. In particular, the prefrontal
cortex of the brain, which is responsible in part for impulse control, decision making, and
the organization and understanding of information, does not complete its development
until about age 25 years (Somerville et al., 2013). It is easy to understand, then, why ado-
lescents may engage in risky behavior even when they know better.
Cognitive Development
8.10 Identify the cognitive and moral advances that occur in adolescence.
If I’m remembering correctly, teenagers should be in Piaget’s formal
operations stage. So why don’t many teenagers think just like adults?The cognitive development of adolescents is less visible than the physical development
but still represents a major change in the way adolescents think about themselves, their
peers and relationships, and the world around them.
PIAGET’S FORMAL OPERATIONS REVISITED Adolescents, especially those who receive
a formal high school education, may move into Piaget’s final stage of formal opera-
tions, in which abstract thinking becomes possible. Teenagers begin to think about
hypothetical situations, leading to a picture of what an “ideal” world would be like.
Piaget’s theory has had a tremendous impact in the education of children and in stimu-
lating research about children’s cognitive development (Hopkins, 2011; Satterly, 1987). Children
in different cultures usually come to understand the world in the way that Piaget described,
although the age at which this understanding comes varies from one child to another.
Although headed into an adult style of thinking, adolescents are not yet completely free
of egocentric thought. At this time in life, however, their egocentrism shows up in their preoc-
cupation* with their own thoughts. They do a lot of introspection (turning inward) and may
become convinced that their thoughts are as important to others as they are to themselves. Two
ways in which this adolescent egocentrism emerges are the personal fable and the imaginary
audience (Elkind, 1985; Galanaki, 2012; Lapsley et al., 1986; Rai et al., 2014; Vartanian, 2000).
In the personal fable, adolescents have spent so much time thinking about their
own thoughts and feelings that they become convinced that they are special, one of a
kind, and that no one else has ever had these thoughts and feelings before them. “You
just don’t understand me, I’m different from you” is a common feeling of teens. The per-
sonal fable is not without a dangerous side. Because they feel unique, teenagers may feel
that they are somehow protected from the dangers of the world and so do not take the
precautions that they should. This may result in an unwanted pregnancy, severe injury
or death while racing in a car, drinking (or texting) and driving, and drug use, to name
a few possibilities. “It can’t happen to me, I’m special” is a risky but common thought.
The imaginary audience shows up as extreme self-consciousness in adolescents.
They become convinced that everyone is looking at them and that they are always the center
Many adolescents feel that they are so
unique, so special, that bad things just
won’t happen to them. This personal fable
can cause some pretty risky behavior, like
what this young man is doing.*preoccupation: extreme or excessive concern with something.
personal fable
tyRe of thought common to adoles-
cents in which young ReoRle Delieve
themselves to De uniSue and Rrotected
from harm.imaginary audience
tyRe of thought common to ado-
lescents in which young ReoRle
Delieve that other ReoRle are Lust as
concerned aDout the adolescentos
thoughts and characteristics as they
themselves are.