ADOLESCENCE

Adolescence (from Latin adolescere, meaning 'to grow up') is a transitional stage

of physical and psychological development that generally occurs during the period
from puberty to legal adulthood (age of majority). Adolescence is usually associated with the
teenage years, but its physical, psychological or cultural expressions may begin earlier and
end later. For example, puberty now typically begins during preadolescence, particularly in
females. Physical growth (particularly in males) and cognitive development can extend into
the early twenties. Thus, age provides only a rough marker of adolescence, and scholars have
found it difficult to agree upon a precise definition of adolescence
A thorough understanding of adolescence in society depends on information from various
perspectives, including psychology, biology, history, sociology, education, and anthropology.
Within all of these perspectives, adolescence is viewed as a transitional period between
childhood and adulthood, whose cultural purpose is the preparation of children for adult
roles. It is a period of multiple transitions involving education, training, employment, and
unemployment, as well as transitions from one living circumstance to another.
The end of adolescence and the beginning of adulthood varies by country. Furthermore, even
within a single nation state or culture, there can be different ages at which an individual is
considered mature enough for society to entrust them with certain privileges and
responsibilities. Such privileges and responsibilities include driving a vehicle, having legal
sexual relations, serving in the armed forces or on a jury, purchasing and drinking alcohol,
voting, entering into contracts, finishing certain levels of education, marriage, and
accountability for upholding the law. Adolescence is usually accompanied by an increased
independence allowed by the parents or legal guardians, including less supervision as
compared to preadolescence.
Reproduction-related changes
Primary sex characteristics are those directly related to the sex organs. In males, the first
stages of puberty involve growth of the testes and scrotum, followed by growth of the
penis. At the time that the penis develops, the seminal vesicles, the prostate, and
the bulbourethral gland also enlarge and develop. The first ejaculation of seminal fluid
generally occurs about one year after the beginning of accelerated penis growth, although this
is often determined culturally rather than biologically, since for many boys first ejaculation
occurs as a result of masturbation. Boys are generally fertile before they have an adult
appearance.
In females, changes in the primary sex characteristics involve growth of the uterus, vagina,
and other aspects of the reproductive system. Menarche, the beginning of menstruation, is a
relatively late development which follows a long series of hormonal changes. Generally, a
girl is not fully fertile until several years after menarche, as regular ovulation follows
menarche by about two years. Unlike males, therefore, females usually appear physically
mature before they are capable of becoming pregnant.
Changes in secondary sex characteristics include every change that is not directly related to
sexual reproduction. In males, these changes involve appearance of pubic, facial, and body
hair, deepening of the voice, roughening of the skin around the upper arms and thighs, and
increased development of the sweat glands. In females, secondary sex changes involve
elevation of the breasts, widening of the hips, development of pubic and underarm hair,
widening of the areolae, and elevation of the nipples. The changes in secondary sex
characteristics that take place during puberty are often referred to in terms of five Tanner
stages, named after the British pediatrician who devised the categorization system.
Changes in the brain
The human brain is not fully developed by the time a person reaches puberty. Between the
ages of 10 and 25, the brain undergoes changes that have important implications for behavior
(see Cognitive development below). The brain reaches 90% of its adult size by the time a
person is six years of age. Thus, the brain does not grow in size much during adolescence.
However, the creases in the brain continue to become more complex until the late teens. The
biggest changes in the folds of the brain during this time occur in the parts of the cortex that
process cognitive and emotional information.
Over the course of adolescence, the amount of white matter in the brain increases linearly,
while the amount of grey matter in the brain follows an inverted-U pattern. Through a process
called synaptic pruning, unnecessary neuronal connections in the brain are eliminated and the
amount of grey matter is pared down. However, this does not mean that the brain loses
functionality; rather, it becomes more efficient due to increased myelination (insulation of
axons) and the reduction of unused pathways.
The first areas of the brain to be pruned are those involving primary functions, such as motor
and sensory areas. The areas of the brain involved in more complex processes lose matter
later in development. These include the lateral and prefrontal cortices, among other regions.
[59]
 Some of the most developmentally significant changes in the brain occur in the prefrontal
cortex, which is involved in decision making and cognitive control, as well as other higher
cognitive functions. During adolescence, myelination and synaptic pruning in the prefrontal
cortex increases, improving the efficiency of information processing, and neural connections
between the prefrontal cortex and other regions of the brain are strengthened. [60] This leads to
better evaluation of risks and rewards, as well as improved control over impulses.
Specifically, developments in the dorsolateral prefrontal cortex are important for controlling
impulses and planning ahead, while development in the ventromedial prefrontal cortex is
important for decision making. Changes in the orbitofrontal cortex are important for
evaluating rewards and risks.
Three neurotransmitters that play important roles in adolescent brain development
are glutamate, dopamine and serotonin. Glutamate is an excitatory neurotransmitter. During
the synaptic pruning that occurs during adolescence, most of the neural connections that are
pruned contain receptors for glutamate or other excitatory neurotransmitters. Because of this,
by early adulthood the synaptic balance in the brain is more inhibitory than excitatory.
Dopamine is associated with pleasure and attuning to the environment during decision-
making. During adolescence, dopamine levels in the limbic system increase and input of
dopamine to the prefrontal cortex increases. The balance of excitatory to inhibitory
neurotransmitters and increased dopamine activity in adolescence may have implications for
adolescent risk-taking and vulnerability to boredom (see Cognitive development below).
Serotonin is a neuromodulator involved in regulation of mood and behavior. Development in
the limbic system plays an important role in determining rewards and punishments and
processing emotional experience and social information. Changes in the levels of the
neurotransmitters dopamine and serotonin in the limbic system make adolescents more
emotional and more responsive to rewards and stress. The corresponding increase in
emotional variability also can increase adolescents' vulnerability. The effect of serotonin is
not limited to the limbic system: Several serotonin receptors have their gene expression
change dramatically during adolescence, particularly in the human frontal and prefrontal
cortex .

Cognitive development
Adolescence is also a time for rapid cognitive development. Piaget describes adolescence as
the stage of life in which the individual's thoughts start taking more of an abstract form and
the egocentric thoughts decrease. This allows the individual to think and reason in a wider
perspective. A combination of behavioural and fMRI studies have demonstrated development
of executive functions, that is, cognitive skills that enable the control and coordination of
thoughts and behaviour, which are generally associated with the prefrontal cortex. The
thoughts, ideas and concepts developed at this period of life greatly influence one's future
life, playing a major role in character and personality formation.
Biological changes in brain structure and connectivity within the brain interact with increased
experience, knowledge, and changing social demands to produce rapid cognitive growth The
age at which particular changes take place varies between individuals, but the changes
discussed below begin at puberty or shortly after that and some skills continue to develop as
the adolescent ages. The dual systems model proposes a maturational imbalance between
development of the socio-emotional system and cognitive control systems in the brain that
contribute to impulsivity and other behaviors characteristic of adolescence.
Theoretical perspectives
There are at least two major approaches to understanding cognitive change during
adolescence. One is the constructivist view of cognitive development. Based on the work
of Piaget, it takes a quantitative, state-theory approach, hypothesizing that adolescents'
cognitive improvement is relatively sudden and drastic. The second is the information-
processing perspective, which derives from the study of artificial intelligence and attempts to
explain cognitive development in terms of the growth of specific components of the thinking
process.
Improvements in cognitive ability
By the time individuals have reached age 15 or so, their basic thinking abilities are
comparable to those of adults. These improvements occur in five areas during adolescence:

1. Attention. Improvements are seen in selective attention, the process by which one
focuses on one stimulus while tuning out another. Divided attention, the ability to pay
attention to two or more stimuli at the same time, also improves
2. Memory. Improvements are seen in both working memory and long-term memory.
3. Processing speed. Adolescents think more quickly than children. Processing speed
improves sharply between age five and middle adolescence; it then begins to level off
at age 15 and does not appear to change between late adolescence and adulthood.
4. Organization. Adolescents are more aware of their thought processes and can use
mnemonic devices and other strategies to think more efficiently.
Hypothetical and abstract thinking
Adolescents' thinking is less bound to concrete events than that of children: they can
contemplate possibilities outside the realm of what currently exists. One manifestation of the
adolescent's increased facility with thinking about possibilities is the improvement of skill
in deductive reasoning, which leads to the development of hypothetical thinking. This
provides the ability to plan ahead, see the future consequences of an action and to provide
alternative explanations of events. It also makes adolescents more skilled debaters, as they
can reason against a friend's or parent's assumptions. Adolescents also develop a more
sophisticated understanding of probability.
The appearance of more systematic, abstract thinking is another notable aspect of cognitive
development during adolescence. For example, adolescents find it easier than children to
comprehend the sorts of higher-order abstract logic inherent in puns, proverbs, metaphors,
and analogies. Their increased facility permits them to appreciate the ways in which language
can be used to convey multiple messages, such as satire, metaphor, and sarcasm. (Children
younger than age nine often cannot comprehend sarcasm at all.) This also permits the
application of advanced reasoning and logical processes to social and ideological matters
such as interpersonal relationships, politics, philosophy, religion, morality, friendship, faith,
fairness, and honesty.
Metacognition
A third gain in cognitive ability involves thinking about thinking itself, a process referred to
as metacognition. It often involves monitoring one's own cognitive activity during the
thinking process. Adolescents' improvements in knowledge of their own thinking patterns
lead to better self-control and more effective studying. It is also relevant in social cognition,
resulting in increased introspection, self-consciousness, and intellectualization (in the sense
of thought about one's own thoughts, rather than the Freudian definition as a defense
mechanism). Adolescents are much better able than children to understand that people do not
have complete control over their mental activity. Being able to introspect may lead to two
forms of adolescent egocentrism, which results in two distinct problems in thinking:
the imaginary audience and the personal fable. These likely peak at age fifteen, along with
self-consciousness in general.
Related to metacognition and abstract thought, perspective-taking involves a more
sophisticated theory of mind. Adolescents reach a stage of social perspective-taking in which
they can understand how the thoughts or actions of one person can influence those of another
person, even if they personally are not involved.
Relativistic thinking
Compared to children, adolescents are more likely to question others' assertions, and less
likely to accept facts as absolute truths. Through experience outside the family circle, they
learn that rules they were taught as absolute are in fact relativistic. They begin to differentiate
between rules instituted out of common sense—not touching a hot stove—and those that are
based on culturally-relative standards (codes of etiquette, not dating until a certain age), a
delineation that younger children do not make. This can lead to a period of questioning
authority in all domains.
Wisdom
Wisdom, or the capacity for insight and judgment that is developed through
experience, increases between the ages of fourteen and twenty-five, then levels off. Thus, it is
during the adolescence-adulthood transition that individuals acquire the type of wisdom that
is associated with age. Wisdom is not the same as intelligence: adolescents do not improve
substantially on IQ tests since their scores are relative to others in their same age group, and
relative standing usually does not change—everyone matures at approximately the same rate
in this way.
Risk-taking
Because most injuries sustained by adolescents are related to risky behavior (alcohol
consumption and drug use, reckless or distracted driving, unprotected sex), a great deal of
research has been done on the cognitive and emotional processes underlying adolescent risk-
taking. In addressing this question, it is important to distinguish whether adolescents are more
likely to engage in risky behaviors (prevalence), whether they make risk-related decisions
similarly or differently than adults (cognitive processing perspective), or whether they use the
same processes but value different things and thus arrive at different conclusions.
The behavioral decision-making theory proposes that adolescents and adults both weigh the
potential rewards and consequences of an action. However, research has shown that
adolescents seem to give more weight to rewards, particularly social rewards, than do adults.
Research seems to favor the hypothesis that adolescents and adults think about risk in similar
ways, but hold different values and thus come to different conclusions. Some have argued
that there may be evolutionary benefits to an increased propensity for risk-taking in
adolescence. For example, without a willingness to take risks, teenagers would not have the
motivation or confidence necessary to leave their family of origin. In addition, from a
population perspective, there is an advantage to having a group of individuals willing to take
more risks and try new methods, counterbalancing the more conservative elements more
typical of the received knowledge held by older adults.
Risk taking may also have reproductive advantages: adolescents have a newfound priority in
sexual attraction and dating, and risk-taking is required to impress potential mates. Research
also indicates that baseline sensation seeking may affect risk-taking behavior throughout the
lifespan. Given the potential consequences, engaging in sexual behavior is somewhat risky,
particularly for adolescents. Having unprotected sex, using poor birth control methods (e.g.
withdrawal), having multiple sexual partners, and poor communication are some aspects of
sexual behavior that increase individual and/or social risk.
Inhibition
Related to their increased tendency for risk-taking, adolescents show impaired behavioral
inhibition, including deficits in extinction learning. This has important implications for
engaging in risky behavior such as unsafe sex or illicit drug use, as adolescents are less likely
to inhibit actions that may have negative outcomes in the future. This phenomenon also has
consequences for behavioral treatments based on the principle of extinction, such as cue
exposure therapy for anxiety or drug addiction. It has been suggested that impaired inhibition,
specifically extinction, may help to explain adolescent propensity to relapse to drug-seeking
even following behavioral treatment for addiction.

Social development
Identity development
Identity development is a stage in the adolescent life cycle. For most, the search for identity
begins in the adolescent years. During these years, adolescents are more open to 'trying on'
different behaviours and appearances to discover who they are. In an attempt to find their
identity and discover who they are, adolescents are likely to cycle through a number of
identities to find one that suits them best. Developing and maintaining identity (in adolescent
years) is a difficult task due to multiple factors such as family life, environment, and social
status. Empirical studies suggest that this process might be more accurately described
as identity development, rather than formation, but confirms a normative process of change in
both content and structure of one's thoughts about the self. The two main aspects of identity
development are self-clarity and self-esteem. Since choices made during adolescent years can
influence later life, high levels of self-awareness and self-control during mid-adolescence will
lead to better decisions during the transition to adulthood. Researchers have used three
general approaches to understanding identity development: self-concept, sense of identity,
and self-esteem. The years of adolescence create a more conscientious group of young adults.
Adolescents pay close attention and give more time and effort to their appearance as their
body goes through changes. Unlike children, teens put forth an effort to look presentable
(1991). The environment in which an adolescent grows up also plays an important role in
their identity development. Studies done by the American Psychological Association have
shown that adolescents with a less privileged upbringing have a more difficult time
developing their identity.
Self-concept
The idea of self-concept is known as the ability of a person to have opinions and beliefs that
are defined confidently, consistent and stable. Early in adolescence, cognitive
developments result in greater self-awareness, greater awareness of others and their thoughts
and judgments, the ability to think about abstract, future possibilities, and the ability to
consider multiple possibilities at once. As a result, adolescents experience a significant shift
from the simple, concrete, and global self-descriptions typical of young children; as children
they defined themselves by physical traits whereas adolescents define themselves based on
their values, thoughts, and opinions.
Further distinctions in self-concept, called "differentiation," occur as the adolescent
recognizes the contextual influences on their own behavior and the perceptions of others, and
begin to qualify their traits when asked to describe themselves. Differentiation appears fully
developed by mid-adolescence. Peaking in the 7th-9th grades, the personality
traits adolescents use to describe themselves refer to specific contexts, and therefore may
contradict one another. The recognition of inconsistent content in the self-concept is a
common source of distress in these years but this distress may benefit adolescents by
encouraging structural development.
Sense of identity
Egocentrism in adolescents forms a self-conscious desire to feel important in their peer
groups and enjoy social acceptance. Unlike the conflicting aspects of self-concept, identity
represents a coherent sense of self stable across circumstances and including past experiences
and future goals. Everyone has a self-concept, whereas Erik Erikson argued that not everyone
fully achieves identity. Erikson's theory of stages of development includes the identity
crisis in which adolescents must explore different possibilities and integrate different parts of
themselves before committing to their beliefs. He described the resolution of this process as a
stage of "identity achievement" but also stressed that the identity challenge "is never fully
resolved once and for all at one point in time". Adolescents begin by defining themselves
based on their crowd membership. "Clothes help teens explore new identities, separate from
parents, and bond with peers." Fashion has played a major role when it comes to teenagers
"finding their selves"; Fashion is always evolving, which corresponds with the evolution of
change in the personality of teenagers. Adolescents attempt to define their identity by
consciously styling themselves in different manners to find what best suits them. Trial and
error in matching both their perceived image and the image others respond to and see, allows
for the adolescent to grasp an understanding of who they are.
Environment and identity
An adolescent's environment plays a huge role in their identity development. While most
adolescent studies are conducted on white, middle class children, studies show that the more
privileged upbringing people have, the more successfully they develop their identity. The
forming of an adolescent's identity is a crucial time in their life. It has been recently found
that demographic patterns suggest that the transition to adulthood is now occurring over a
longer span of years than was the case during the middle of the 20th century. Accordingly,
youth, a period that spans late adolescence and early adulthood, has become a more
prominent stage of the life course. This therefore has caused various factors to become
important during this development. So many factors contribute to the developing social
identity of an adolescent from commitment, to coping devices, to social media. All of these
factors are affected by the environment an adolescent grows up in. A child from a more
privileged upbringing is exposed to more opportunities and better situations in general. An
adolescent from an inner city or a crime-driven neighborhood is more likely to be exposed to
an environment that can be detrimental to their development. Adolescence is a sensitive
period in the development process, and exposure to the wrong things at that time can have a
major effect on future decisions. While children that grow up in nice suburban communities
are not exposed to bad environments they are more likely to participate in activities that can
benefit their identity and contribute to a more successful identity development.
Sexual orientation and identity
Sexual orientation has been defined as "an erotic inclination toward people of one or more
genders, most often described as sexual or erotic attractions". In recent years, psychologists
have sought to understand how sexual orientation develops during adolescence. Some
theorists believe that there are many different possible developmental paths one could take,
and that the specific path an individual follows may be determined by their sex, orientation,
and when they reached the onset of puberty.
In 1989, Troiden proposed a four-stage model for the development of homosexual sexual
identity. The first stage, known as sensitization, usually starts in childhood, and is marked by
the child's becoming aware of same-sex attractions. The second stage, identity confusion,
tends to occur a few years later. In this stage, the youth is overwhelmed by feelings of inner
turmoil regarding their sexual orientation, and begins to engage sexual experiences with
same-sex partners. In the third stage of identity assumption, which usually takes place a few
years after the adolescent has left home, adolescents begin to come out to their family and
close friends, and assumes a self-definition as gay, lesbian, or bisexual. In the final stage,
known as commitment, the young adult adopts their sexual identity as a lifestyle. Therefore,
this model estimates that the process of coming out begins in childhood, and continues
through the early to mid 20s. This model has been contested, and alternate ideas have been
explored in recent years.
In terms of sexual identity, adolescence is when
most gay/lesbian and transgender adolescents begin to recognize and make sense of their
feelings. Many adolescents may choose to come out during this period of their life once an
identity has been formed; many others may go through a period of questioning or denial,
which can include experimentation with both homosexual and heterosexual experiences. A
study of 194 lesbian, gay, and bisexual youths under the age of 21 found that having an
awareness of one's sexual orientation occurred, on average, around age 10, but the process of
coming out to peers and adults occurred around age 16 and 17, respectively.[124] Coming to
terms with and creating a positive LGBT identity can be difficult for some youth for a variety
of reasons. Peer pressure is a large factor when youth who are questioning their sexuality
or gender identity are surrounded by heteronormative peers and can cause great distress due
to a feeling of being different from everyone else. While coming out can also foster better
psychological adjustment, the risks associated are real. Indeed, coming out in the midst of a
heteronormative peer environment often comes with the risk of ostracism, hurtful jokes, and
even violence. Because of this, statistically the suicide rate amongst LGBT adolescents is up
to four times higher than that of their heterosexual peers due to bullying and rejection from
peers or family members.
Self-esteem
The final major aspect of identity formation is self-esteem. Self-esteem is defined as one's
thoughts and feelings about one's self-concept and identity. Most theories on self-esteem state
that there is a grand desire, across all genders and ages, to maintain, protect and enhance their
self-esteem. Contrary to popular belief, there is no empirical evidence for a significant drop
in self-esteem over the course of adolescence. "Barometric self-esteem" fluctuates rapidly
and can cause severe distress and anxiety, but baseline self-esteem remains highly stable
across adolescence. The validity of global self-esteem scales has been questioned, and many
suggest that more specific scales might reveal more about the adolescent experience. Girls are
most likely to enjoy high self-esteem when engaged in supportive relationships with friends,
the most important function of friendship to them is having someone who can provide social
and moral support. When they fail to win friends' approval or couldn't find someone with
whom to share common activities and common interests, in these cases, girls suffer from low
self-esteem. In contrast, boys are more concerned with establishing and asserting their
independence and defining their relation to authority. As such, they are more likely to derive
high self-esteem from their ability to successfully influence their friends; on the other hand,
the lack of romantic competence, for example, failure to win or maintain the affection of the
opposite or same-sex (depending on sexual orientation), is the major contributor to low self-
esteem in adolescent boys. Due to the fact that both men and women happen to have a low
self-esteem after ending a romantic relationship, they are prone to other symptoms that is
caused by this state. Depression and hopelessness are only two of the various symptoms and
it is said that women are twice as likely to experience depression and men are three to four
times more likely to commit suicide (Mearns, 1991; Ustun & Sartorius, 1995).