Section 20.1 Adolescence: A Time of Change Objectives List three main categories of physical changes that occur during adolescence. Describe three mental changes that adolescents experience. Summarize the emotional changes of adolescence.

Dear Advice Line, I’m very self-conscious because I look more grown up than all of my friends. I’m tired of people staring at me and making comments about my body. What can I do? What advice and reassurances would you offer this teen?

Changes in Your Body From about the ages of 12 to 19, you gradually change from a child into an adult. This period of gradual change is called adolescence. During adolescence, the reproductive system matures, adult features appear, and height and muscle mass increase.

Reproductive System Puberty refers specifically to the changes that happen to your reproductive system. The release of sex hormones causes girls to begin to ovulate and menstruate, and boys to begin to produce sperm. Ovulation in girls and sperm production in boys signal reproductive maturity, or the ability to produce children.

Appearance The sex hormones also cause the development of secondary sex characteristics, which are physical changes that develop during puberty, but are not directly involved in reproduction. Some adolescents have difficulty adjusting to their changing body shape, or may be embarrassed or confused about the sexual changes occurring to their bodies.

Height and Muscle Mass Around the same time that puberty starts, the pituitary gland also increases its production of growth hormone. Growth does not occur in a regular fashion, but in spurts. Girls tend to begin their growth spurt earlier than boys. Boys start their growth spurt later, but they grow for a longer period of time.

Growing Pains Rapid lengthening of the bones in your arms and legs can cause aches and cramps. If you challenge your growing body with a variety of physical activities, you will adjust more rapidly to your new size and shape. Physical activity will help to develop your muscles and your coordination. As unlikely as it may seem, your feelings of discomfort and awkwardness will soon disappear.

Energy Demands Growth makes you hungry. This is normal during adolescence because you need extra energy to fuel your growing body. It is important to eat nutritious meals and snacks to supply your body with the nutrients it needs.

Early Bloomers and Late Bloomers The age range for the “normal” onset of puberty is wide. Adolescents who develop at an early age, before most other adolescents, are sometimes called early bloomers. Those who develop at a late age, after most other adolescents, are called late bloomers. Most early bloomers and late bloomers are developing at a normal rate. The ages at which people mature sexually and grow to their adult height are determined in large part by heredity and your overall state of health.

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Mental Changes Changes in the way you think and feel have more to do with changes occurring in your brain. In your first few years of life, millions of brain cells and the pathways connecting them formed. When you were between 10 and 13 years old, a second dramatic wave of growth and development took place. Mental changes during adolescence include improved abstract thinking, reasoning skills, and impulse control.

Abstract Thinking When you were a child, your thoughts and feelings were tied directly to your physical experiences at each moment. Now it is easier for you to think abstractly—to consider ideas that are not concrete or visible. Your growing ability to think abstractly is partly due to the dramatic growth in your brain’s frontal cortex.

Reasoning Skills During adolescence, changes to your brain help to expand your reasoning abilities. You are becoming increasingly able to see more than one side of a question and to think through the pros and cons of decisions you face.

Impulse Control Some teenagers find that their impulses, or tendencies to act rapidly based on emotional reactions, are sometimes clouding their decision-making abilities. The emotional region of an adolescent’s brain is more active than the same region in an adult’s brain. Removing yourself from an intense situation and taking some time to think things through can help you stay in control.

The Adolescent Brain Corpus Callosum Frontal Cortex This cable of nerves that connects the two halves of the cerebrum grows and changes throughout adolescence. It aids creativity and problem-solving abilities. Frontal Cortex This “thinking” region of the brain’s cerebrum plays a role in planning, judgment, and memory. Dramatic growth occurs in this region at about age 11 for girls and 12 for boys. Cerebellum This part of the brain, which coordinates physical movement, grows and changes dramatically during the teen years. Amygdala This “emotional center” of the brain is partly responsible for your impulses, or gut responses to emotional situations.

Emotional Changes You may begin to question many things that you have simply accepted until now. During adolescence, individuals start to define meaning in their lives, a set of personal values, and a sense of self.

Search for Meaning During adolescence, it is not unusual to suddenly question whether your friends are really true friends and whether happiness and love are possible to attain. These questions signal that you have begun to search for meaning in life. This search is important because you are beginning to choose a way of life that is right for you.

Search for Values Have you started to question the opinions and beliefs of others? This process helps you discover your values. Parents, teachers, and other adults can help you clarify your values. For the most part, many of the values that adolescents eventually come to accept are similar to those of their parents.

Search for Self Some of the most difficult questions that adolescents ask concern themselves and their place in the world. Search for identity may take many forms. If you are like many adolescents, your self-esteem may not be as high today as it was a few years ago. Try listing your accomplishments and writing about your talents in a journal.

Vocabulary adolescence The period from about age 12 to 19 during which a child gradually changes into an adult. reproductive maturity The ability to produce children, signaled by the onset of ovulation in girls, and of sperm production in boys. secondary sex characteristics Physical changes during puberty that are not directly involved in reproduction.

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