Psychology

Adolescence is a stage in a persons life between puberty and adulthood. The stage usually falls between the ages of 10 to the early 20s. The children become young adults. It involves maturity in both social and physical aspects of an individual thus making them to become sexually mature and socially independent. This stage also involves them starting to develop a sense of who they are and they tend to learn more from people outside their families.

Major milestones related to the physical development in adolescence
The physical growth and development during adolescence includes both an increase in body size and also sexual maturation which is usually referred to as puberty. How fast these changes occur to a person varies from one person to another and is usually affected by both the environment and heredity factors. During the adolescence, the boys and girls reach their average adult weight and height. In the boys, the growth spurt usually occurs between the ages of 12 to 17 years. They also grow about 4 inches (ten centimeters) during the year of maximum growth.

The growth spurt in girls usually occurs faster and early which is usually between the ages of 912 and 1412. They on the other hand grow to around 9 centimeters in height during their maximum growth year. In other words, the boys tend to become taller and heavier than girls. By the age of 18, the boys usually have two centimeters of growth left while the girls having slightly less. The specific physical milestone for the boys includes  the changes in voice meaning that the voice becomes deeper and husky, this occurs between the age of 1012 and 18 years growth of the scrotum and testes between the ages of 1012 and 18 years this is followed by the lengthening of the penis between 11 and 15 years public hair growth then follows between 11 and 14 years. At this point in time, the adolescent has reached his peak growth spurt. It is then followed by minor changes in body shape and finally the growth in facial hair between the ages of 13 to 18 years.

In the adolescence, girls milestones includes breast budding between 8-13 years growth of pubic hair between 8-14 years which signifies the peak of their growth spurt other changes are that they start to experience their first period (menarche) between 10-16 years then the growth of underarm hair between 912- 1612 followed by changes in body shape at around 1512 years and they finally develop adult size breasts between 16-17 years.

Major milestones related to the cognitive development in adolescence
Cognitive development is sometimes referred to as mental or intellectual development. Cognitive activities include perception, thinking, and reasoning, problem solving ability, concept development and abstract thinking. One of the most important and complicated cognitive activities is language development. During adolescence the precursors to formal operational thinking develops well and includes a limited ability to think hypothetically and also making multiple perspectives. During the middle and late years in the adolescent stage, the formal operational thinking becomes well developed and it is integrated in a significant and major percentage of their lives. The adolescents long-term knowledge base continues to expand they also develop more complex rules for solving problems and become less self-conscious and focused in addition, they become better in their day to day lives in terms of planning and decision making they are also able to evaluate vocational options in terms of their interests, values and abilities.

During the late adolescence stage, they develop the ability to narrow their vocational options and settle on specific careers.

Major milestones related to the physical development in early, middle, and late adulthood
Early adulthood ranges from 20 years to early 40 years. In these ages, there are several physical milestones that are usually visible. They include some gain in height and body muscle and fat which is the peak of their strength, energy and endurance the brain also grows in size during this stage although there are no new neurons that are formed at this stage by the mid 20s, the body functions are usually fully developed including the sharpest senses.

In the middle adulthood the physical developmental milestones depicts much decline compared to other early stages some of it attributes include the ability to focus declines and in some cases they loose their near vision abilities and hence need more brightness. Their sensory and motor functioning reduces with a loss in the ability to hear high pitched sounds. Their reaction time slows, especially for motor responses. Their general physical strengths also start to decline.

The physical changes during late adulthood include mostly more problems for people in this stage some of the milestones include an almost total decline in taste, vision and even smell they also lose their ability to detect pain or even notice temperature change. These declines usually develop gradually and become more pronounced in late 70s plus. Other physical attributes include rising blood pressure, neural loss, declining lung capacity and a change is sexuality is also evident. Most of these changes are inevitable though they vary according to individuals.

Major milestones related to the cognitive development in early, middle, and late adulthood
The cognitive development in young adults involves many things that tend to make people in this stage to have high mental and intellectual abilities. In this stage, these young adults are able to apply their intelligence in situations that have profound consequences in the process of achieving long-term goals like the ones that involve careers. This stage also includes the mastering of cognitive skills that one needs to monitor hisher own behavior. They will also acquire a considerable amount of independence in this stage.

Cognitive development in middle adulthood is usually multidirectional, meaning that there are gains in some areas and losses in others. On the declining side are the ability to apply mental powers to new problems there is also a decline in the way people perceive formal concepts, relationships, and drawing inferences. These declines in mental activity are usually attributed to changes in the brain. These changes also affect the ability to remember and use information acquired over a lifetime. On the gaining part is that they are able to reconcile or choose among conflicting views, thesis and antithesis.

In the late adulthood, one tends to experience a decline in all the primary mental abilities. For instance, in the sensory register, they experience a small decline in ones brain power and sensitivity though this varies with individuals. The working memory whose main role is to store unconscious information is noticeably decreased as this makes processing of information to take a longer time.

Socio- emotional development in adolescence
The brain regions that control emotions tend to develop and mature during adolescence. This period that is characterized by emotional outbursts can prove to be quite challenging for the parents and also teachers. Adolescents however learn how to suppress inappropriate thoughts and actions and replace them with goal-oriented ones.

In this stage, the adolescent also develops a sense of self in relationships to other people and their own internal thoughts and desires. Though opposite sex interactions are frequent in late-childhood, they usually increase during the adolescence stage. This is mainly due to the coming out of romantic attraction, which is both a biological as well as societal standards product. Adolescence dating can be a source of intimacy, heightened self esteem, expanded social competency and also peer status. On the negative side, it can be a source of abuse, jealousy and damage to self esteem if not monitored accordingly. Adolescents also desire autonomy meaning separation from parents and becoming independent adults. Such desires can lead to plenty of family conflicts and defiant characteristics leading to what psychologists refer to as psychological storm.

Major milestones related to the socio-emotional development in early, middle, and late adulthood
Socio-emotional milestones related to early adulthood include the ability to give and receive love a person begins to make long-term commitments to relationships. People in this stage also discover the importance of romantic relationships and individuation since this is what leads to marriage. Their relationships in this stage are mostly influenced on how their parent and peers interacted with one another. For instance, securely attached children are most likely to become securely attached with their spouses in this stage. In addition to that, past experiences also influence their parental behavior.
In the middle and old adulthood stage, the individuals tend to develop interest in guiding the development of the next generation. In the late adulthood, an individual develops a sense of acceptance of life as it was lived and the importance of the people and relationships that individuals develop over a lifespan.

In the Erikssons Stage of Generativity versus Stagnation theory, Eriksson insists that if one has a strong sense of creativity, success and having to leave a mark in life, one needs to develop the act of generativity, meaning that they need to concentrate on the next generation by caring about them and acting as a link for the generations to come and give love without any expectation of a specific return. On the other hand, adults who develop a sense of stagnation, become self absorbed and hence feel little connection to others as they generally offer little or none to the society. It is important to note that too much stagnation can lead people developing a sense of rejectivity and  too much generativity can lead to overextension which means people have no time for themselves simply because they are too busy dealing with other peoples issues.