1. The Teen Years, Explained
An Overview of Healthy Adolescent Development

2. The Second Decade
At no other time except infancy do human beings pack so much development into such a short period.
During adolescence, children gain 50% of their adult body weight, become capable of reproducing, and experience an astounding transformation in their brains.
All of these changes occur during – and are often the cause of – a rapid change in adolescents' social spheres. For example, teens start assuming adult responsibilities such as finding a job, figuring out romantic relationships, and learning how to be a good friend.

3. The Second Decade
Adolescence can therefore be a confusing time, as there are so many conflicting things happening.
On one hand, there are positive changes occurring; you may find yourself taller, stronger, or faster, and you may be given greater freedom and control over certain aspects of your life.
However, negative changes can occur, too; you may find yourself more self-conscious, tired, moody, or concerned that you’re not developing in the same ways as your peers.
Regardless of the changes you’re personally experiencing, it’s important to note that these fluctuations are both natural, and necessary. (And definitely won’t last forever!)

4. The Teenage Brain

5. Stages of Adolescent Development
There are three stages of adolescence:
Early Adolescence, which occurs approximately between the ages of 11 and 13
Middle Adolescence, which occurs approximately between the ages of 14 and 18
Late Adolescence, which occurs approximately between the ages of 19 and 21

6. Stages of Adolescent Development
In each stage of adolescence, different types of development occur:
Physical Development: changes affecting your body, appearance, etc.
Cognitive Development: changes affecting your thought processes
Social-Emotional Development: changes affecting the way you form and maintain relationships, as well as your expression of emotions

7. Early Adolescence: Physical Development
puberty is at its most active stage
grow body hair
tremendous physical growth (gain height and weight)
increase perspiration and oil production in hair and skin
girls – breast and hip development; onset of menstruation
boys – growth in testicles and penis; deepening of voice
increased sexual interest

8. Early Adolescence: Cognitive Development
growing capacity for abstract thought
mostly interested in present with limited thought about the future
intellectual interests expand and become more important
deeper moral thinking

9. Early Adolescence: Social-Emotional Development
struggle with sense of identity
feel awkward about one’s self and one’s body; worry about being “normal”
realize that parents are not perfect; increased conflict with parents
increased influence of peer group
desire for independence
tendency to return to “childish” behavior, particularly when stressed
moodiness
rule and limit testing
greater interest in privacy

10. Middle Adolescence: Physical Development
puberty may just be starting, or may be coming to an end
physical growth often slows for girls
physical growth often continues for boys

11. Middle Adolescence: Cognitive Development
continued growth of capacity for abstract thought
greater capacity for setting goals
interest in moral reasoning
thinking about the meaning of life

12. Middle Adolescence: Social-Emotional Development
intense self-involvement, fluctuating between high expectations and poor self-concept
continued adjustment to changing body; worries about being normal
tendency to distance selves from parents; continued drive for independence
driven to make friends and greater reliance on them; popularity can be an important issue
feelings of love and passion

13. Late Adolescence: Physical Development
young women are typically fully developed
young men typically continue to gain height, weight, muscle mass, and body hair

14. Late Adolescence: Cognitive Development
ability to think ideas through
ability to delay gratification
examination of inner experiences
increased concern for future
continued interest in moral reasoning

15. Late Adolescence: Social-Emotional Development
firmer sense of identity
increased emotional stability
increased concern for others
increased independence and self-reliance
peer relationships remain important
development of more serious relationships
social and cultural traditions regain some of their importance