Synonyms

Teenagers; Teens; Youth

Definition

Adolescence is the life stage that bridges childhood and adulthood. This transitional period is characterized by significant biological, cognitive, and psychosocial changes. Although the age range of adolescence varies by cultural and historical circumstance, the beginning is typically marked by the onset of puberty and the conclusion is associated with the full assumption of adult roles. This means that in the United States and most industrialized countries today adolescence roughly describes the second decade of life.

Description

Adolescence is typically divided into two periods. Early adolescence corresponds with the middle school or junior high school years, and late adolescence corresponds with the latter half of the second decade of life. Early adolescence is characterized by the significant biological changes associated with puberty while late adolescence features identity, career, and relational exploration. There is a growing recognition that college aged young people do not resemble adolescents in terms of their developmental activities. Instead, Arnett and a growing group of others in the field refer to young people between 18 and 25 years of age as emerging adults [2].

Historically, adolescence has been viewed as a time of “storm and stress.” Early adolescent researchers believed the adolescent life stage was a time of irrationality, moodiness, and turbulence (see G. Stanley Hall). However, little empirical research supports this negative view. While adolescence is a period of significant change, research finds that most adolescents around the world have a positive self-image, are self-confident and optimistic about their future, are happy most of the time, enjoy life, value work and school, have positive feelings toward their families, and demonstrate the capacity to cope with life’s stresses [19]. As a result, most psychologists and practitioners today embrace a more positive view of adolescents, and research increasingly emphasizes their hope, optimism, creativity, and purposes in life [5].

Following is a brief discussion of the biological, cognitive, and psychosocial changes that represent the primary areas of growth associated with normative adolescent development.

Biological Development

The onset of adolescence is marked by the physical changes associated with puberty. According to Marshall [18], puberty is characterized by significant height and weight gain, the development of primary and secondary sex characteristics, changes in body composition, and changes in the circulatory and respiratory systems. The endocrine system, which is responsible for producing, circulating, and regulating hormonal levels, plays an important role in triggering and regulating puberty.

Puberty is associated with the most significant increase in growth since infancy. The release of growth hormones, thyroid hormones, and androgens stimulate the rapid increase in height and weight. At least as noteworthy as the absolute increase in size is the rate of growth during adolescence; nearly half of adult weight is gained during adolescence [22]. At the peak of pubertal change boys grow about 4 in./year and girls about 3½ in./year.

The timing and tempo of puberty are influenced by a combination of highly variable genetic and environmental factors. In the United States boys typically start puberty between 9½ and 13½ years of age, and girls typically experience the onset between 7 and 13 years of age. In boys puberty tends to last between 2 and 5 years, while for girls it typically extends between 1½ and 6 years. Over the past 100 years the average age of the onset of puberty has dropped due to improvements in health, nutrition, and living conditions [1].

As young people undergo puberty they often become preoccupied with their changing bodies (Brausch & Gutierrez, 2009). Throughout puberty, boys tend to develop a more positive self-image as their bodies fill out, their faces take on a more angular appearance, and their voices deepen. Girls, on the other hand, are likely to become less pleased with their changing bodies as they gain weight and fat [4]. Changes in self-image affect the way adolescents perceive themselves and the way others treat them. For example, a young person who has recently gone through puberty may feel older and seek to be treated more like an adult, and other people expect more adult-like behavior from a fully mature adolescent.

Cognitive Development

Along with the rest of the body, the adolescent brain experiences noteworthy physical changes. For example, as a result of synaptic pruning – the process through which unnecessary connections between neurons are eliminated – the brain undergoes considerable restructuring during adolescence. Myelination, or the process in which the neuronal projections that connect to form brain circuits become encased in a fatty substance, facilitates the transmission of impulse flow. The combination of myelination and synaptic pruning allows the brain to process information more quickly and more efficiently [13].

It is not just that adolescent’s become more efficient at processing information; they also begin to think and reason in qualitatively different ways. Whereas children tend to think in a concrete and absolute manner, adolescents become increasingly able to engage in thinking and reasoning that is abstract and relative. Deductive (reasoning in which one draws logically necessary conclusions from a general set of premises), and inductive reasoning (in which one draws a general conclusion from a set of specific facts) emerge, and adolescents develop the ability to engage in metacognition, or thinking about thinking.

Several scholars, including Piaget and Vygotsky, have offered theories that describe the process of cognitive development during adolescence. Piaget’s cognitive developmental theory situates most adolescents in the formal operational stage, which is characterized by the development of abstract, propositional, and hypothetical-deductive reasoning. Idealism and possibilities are the hallmark of formal operational thought. At the same time as Piaget was devising his theory of cognitive development, Vygotsky was engaged in the same task. However, he came to a somewhat different conclusion regarding the nature of cognition. Vygotsky proposed a sociocultural cognitive theory that emphasizes the central role of learning from more skilled others. According to Vygotsky learning is situated in a particular cultural context and collaborative, meaning that social interactions guide development [14].

The more contemporary information processing theory represents a third influential perspective on adolescent cognitive development. Comparing the functioning brain to a computer, this theory emphasizes the way that adolescents manipulate, monitor, and strategize about information in order to make decisions and solve problems [20].

Psychosocial Development

In addition to the biological and cognitive changes that accompany this stage of life, adolescence is also characterized by significant psychosocial development, including growth in the areas of identity, gender, sexuality, morality, and intimacy. According to Erik Erikson [10–12], the establishment of a coherent sense of self, or identity, is the major task of adolescence. Prior to adolescence, children have a scattered, inconsistent conception of who they are, but during adolescence they develop a more unified and enduring picture of who they are and of who they hope to become. For some adolescents, especially minority youth, integrating a sense of ethnic identity into their overall sense of self is an important part of their identity development.

Like ethnicity, gender represents a significant component of an individuals’ identity. From birth, boys and girls are socialized to act in gender specific ways. According to the gender intensification hypothesis [15], pressure to behave in sex-appropriate ways may temporarily intensify during early adolescence.

The development of sexuality coincides with the greater understanding of what it means to be male and female. While much attention is given to adolescent problems in the area of sexuality, most adolescents have healthy sexual attitudes and engage in sexual behaviors that are not likely to have long-term, negative consequences [9]. According to a national survey of adolescents, sexual intercourse is rare among early adolescents but common among late adolescents [8]. For instance, in the United States only 22% of girls and 27% of boys report being sexually active at 15, but 76% of girls and 85% of boys say they have had sex by 19 years of age.

Moral development, another important feature of adolescent psychosocial development, encompasses reasoning, behaviors, and feelings regarding standards of right and wrong. According to Kohlberg [16] most adolescents reason about moral matters at the conventional reasoning level, meaning they abide by standards of right and wrong that they view as external to themselves, typically belonging to either their parents or society. While Kohlberg’s theory helps explain how adolescents reason about moral issues, it does not explain why adolescents ultimately act in moral or immoral ways. Instead, Bandura [3] social cognitive theory of moral development is useful in explaining how adolescents learn to enact moral behavior. According to this model, young people learn what is right and wrong through observation. Over time, young people internalize the broader society’s standards of right and wrong, and self-sanctions keep their actions in line with their beliefs. In other words, adolescents experience a diminished sense of self-worth when their actions contradict their moral sense. Moral identity offers another perspective on moral action. During adolescence some young people develop a sense of moral beliefs or commitments that are central to their sense of who they are [6]. For these youth, acting in ways that violates their moral sense, or moral identity, jeopardizes the integrity of their sense of self [17].

Balancing a growing desire for autonomy with a continued need for connectedness is another important task of adolescence. As young people mature, they begin to crave the independence associated with adulthood. However, at the same time as adolescents seek more autonomy, they also begin to seek more intimacy in their relations with others. Peer and family relationships during adolescents differ from relationships during childhood in they are more likely to be characterized by openness, honesty, self-disclosure, and trust. While family support and connections remain important to adolescents, peer relationships become increasingly significant. In early adolescence, peer relationships tend to feature same sex friendships, but during middle and late adolescence, they often include opposite sex friendships and sexual relationships, too [21].

Identity, morality, gender, sexuality, autonomy, and intimacy are issues that resurface throughout the lifespan. However, because of the biological and cognitive changes associated with adolescence, they are particularly salient issues during this stage in life. It is also important to keep in mind that each of these aspects of development takes place within a variety of contexts including family, peer, school, and cultural contexts that influence adolescent development in important ways. Bronfenbrenner’s ecological systems model describes the way an individual’s development is simultaneously influenced by and influences the multiple contexts in which it is embedded [7].