The development of children ages 12 through 18 years old is expected to include predictable physical and mental milestones.

During adolescence, children develop the ability to:

• Comprehend abstract content, such as higher mathematic concepts, and develop moral philosophies, including rights and privileges
• Establish and maintain satisfying personal relationships by learning to share intimacy without inhibition or dread
• Move gradually towards a more mature sense of identity and purpose
• Question old values without a sense of dread or loss of identity

PHYSICAL DEVELOPMENT

Adolescence is characterized by dramatic physical changes moving the individual from childhood into physical maturity. Early, prepubescent changes are noted with the appearance of secondary sexual characteristics.

Girls may begin to develop breast buds as early as 8 years old, with full breast development achieved anywhere from 12 to 18 years. Pubic hair growth -- as well as armpit and leg hair -- typically begins at about age 9 or 10, and reaches adult distribution patterns at about 13 to 14 years.

Menarche (the beginning of menstrual periods) typically occurs about 2 years after initial pubescent changes are noted. It may occur as early as 10 years, or as late as 15 years, with the average in the United States being about 12.5 years. A rapid growth in height occurs for girls between the ages of about 9.5 and 14.5 years, peaking somewhere around 12 years.

Boys may begin to notice enlargement of the testicles and scrotum as early as 9 years of age, followed closely by lengthening of the penis. Adult size and shape of the genitals is typically reached by age 16 to 17 years. Pubic hair growth -- as well as armpit, leg, chest, and facial hair -- begins in boys at about age 12, and reaches adult distribution patterns at about 15 to 16 years.

A rapid growth in height occurs for boys between the ages of about 10.5 to 11 and 16 to 18, peaking around age 14. Puberty is not marked with a sudden incident in boys, as it is with the onset of menstruation in girls. The appearance of regular nocturnal emissions (wet dreams) marks the onset of puberty in boys and typically occurs between the ages of 13 and 17 years, with the average about 14.5 years.

Voice change in boys typically occur along with penile growth, and the occurrence of nocturnal emissions occurs with the peak of the height spurt.

BEHAVIOR

The sudden and rapid physical changes that adolescents experience typically lend this period of development to be one of self-consciousness, sensitivity and concern over one's own body changes, and excruciating comparisons between oneself and one's peers.

Because physical changes may not occur in a smooth, regular schedule, adolescents may go through stages of awkwardness, both in terms of appearance and physical mobility and coordination. Unnecessary anxieties may arise if adolescent girls are not informed and prepared for the onset of menstrual periods, or if adolescent boys are not provided accurate information about nocturnal emissions.

During adolescence, it is appropriate for youngsters to begin to separate from their parents and establish an individual identity. In some cases, this may occur with minimal reaction on the part of all involved.

However, in some families, significant conflict may arise over the adolescent's acts or gestures of rebellion, and the parents' needs to maintain control and have the youth comply.

As adolescents pull away from parents in a search for identity, the peer group takes on a special significance. It may become a safe haven, in which the adolescent can test new ideas and compare physical and psychological growth.

In early adolescence, the peer group usually consists of non-romantic friendships, often including "cliques," gangs, or clubs. Members of the peer group often attempt to behave alike, dress alike, have secret codes or rituals, and participate in the same activities. As the youth moves into mid-adolescence (14 to 16 years) and beyond, the peer group expands to include romantic friendships.

Mid-to-late adolescence is characterized by a need to establish sexual identity through becoming comfortable with one's own body and sexual feelings. Through romantic friendships, dating, and experimentation, adolescents learn to express and receive intimate or sexual advances in a comfortable manner that is consistent with internalized values.

Young people who do not have the opportunity for such experiences may demonstrate difficulty in establishing intimate relationships into adulthood.

Adolescents typically demonstrate behaviors consistent with several myths of adolescence:

• The first myth is that they are "on stage" with the attention of others constantly centered upon their appearance or actions. This preoccupation stems from the fact that adolescents spend so much time thinking about and looking at themselves, it is only natural to assume that everyone else is also thinking and looking at them as well. In reality, this isn't the case, because "everyone else" (usually peers) is too preoccupied with his or her own situation. This normal self-centeredness may appear (especially to adults) to border on paranoia, narcissism, or even hysteria.
• Another myth of adolescence is that of the indestructible self. This belief feeds the notion that "it will never happen to me, only the other person". In this sense, "it" may represent becoming pregnant or catching a sexually-transmitted disease after having unprotected intercourse, causing a car crash while driving under the influence of alcohol or drugs, developing oral cancer as a result of chewing tobacco, or any of the many adverse effects of a wide range of risk-taking behaviors.

SAFETY

Adolescent safety issues stem from increased strength and agility that may develop before they've developed good decision-making skills. A strong need for peer approval, coupled with the myths of adolescence, may entice a young person to attempt hazardous feats, or participate in a variety of risk-taking behaviors.

Appropriate motor vehicle safety should be emphasized, focusing on the roles of driver/passenger/pedestrian, the influence of substance abuse, and the importance of using seat belts. Privileges associated with cars and recreational motor vehicles should depend on the adolescent's ability to demonstrate an adequate knowledge of and safe use of such vehicles.

Adolescents involved in recreational athletic activities should be taught to use adequate equipment, protective gear or clothing, safe facilities, proper rules of safe play, and rational approaches to activities requiring advanced skill levels.

Young people need to be acutely aware of the potential dangers -- including sudden death -- which may occur not only with regular substance abuse, but even experimental use of drugs and alcohol.

Adolescents who are allowed to use or have access to firearms need to learn proper use, safety, and legal requirements associated with guns.

If adolescents appear to be isolated from peers, uninterested in school or social activities, or deteriorating in performance at school, work, or sports -- psychological evaluation may be necessary.

Many adolescents are at increased risk for depression and potential suicide attempts, due to pressures and conflicts that may arise within families, school or social organizations, and intimate relationships.

PARENTING TIPS

Adolescents usually require privacy in which to contemplate the changes taking place in their bodies. Ideally, the youth should be allowed to have a private bedroom. If this is not possible, some private space should be allotted.

Teasing an adolescent child about physical changes is inappropriate, because it may cause self-consciousness and embarrassment.

Parents need to remember that the adolescent's interest in body changes and sexual topics is natural, normal development and does not necessarily indicate movement into sexual activity.

Parents must take care not to label emerging drives and behaviors as wrong, "sick", or immoral. Adolescents may experiment with or consider a wide range of sexual orientations or behaviors prior to feeling comfortable with their own sexual identity.

A re-emergence of the Oedipal complex (a child's attraction to the parent of the opposite sex) is common during adolescent years. Healthy parents deal with this by acknowledging the physical changes and attractiveness of the child -- and taking pride in the youth's growth into maturity -- without crossing appropriate parent-child relationship boundaries.

It is normal for the parent to find the adolescent attractive, particularly as the teen often looks very much like the other (same-sex) parent did at a younger age. This attraction may cause the parent to feel awkward, but care should be taken by the parent not to create disconnection, which may potentially make the adolescent feel responsible. It is inappropriate for a parent's attraction to a child to be anything more than an attraction as a parent. Attraction that crosses the parent-child boundaries may lead to inappropriately intimate behavior with the adolescent, which is known as incest.

The teenager's quest for independence is normal development and need not be seen by the parent as rejection or a loss of control over the child. To be of most benefit to the growing adolescent, a parent needs to be a constant and consistent figure, available as a sounding board for the youth's ideas without dominating or overtaking the emerging, independent identity of the young person.

Despite adolescents constantly challenging authority figures, they need or want limit-setting, as it provides a safe boundary in which to grow and function. Limit-setting refers to predetermined and negotiated rules and regulations regarding behavior.

In contrast, power struggles arise when authority is at stake or "being right" becomes the primary issue. These situations should be avoided, if possible. Ultimately, one of the parties (typically the teen) is overpowered, causing the youth to lose face. This can cause the adolescent to feel embarrassment, inadequacy, resentment, and bitterness.

Parents should be prepared for and recognize that there are common conflicts that may develop while parenting adolescents. The experience may be influenced by unresolved issues from a parent's own childhood, as well as unresolved issues from the adolescent's earlier years.

Parents can anticipate their authority to be repeatedly challenged, as children enter and move through their adolescent years. Maintaining open lines of communication and clear, yet negotiable, limits or boundaries may prove useful in minimizing major conflicts.

Most parents report a sense of increased wisdom and self-growth as they rise to the challenges of parenting adolescents.