Psychology

Human beings constantly change from conception until death. Mostly due to common psychological and biological make up. Development refers to growth or progression to the stages later in life, in human beings this refers to maturity. Lifespan development refers to cognitive, socioemotional and biological processes from birth to infancy to adolescence followed by adulthood, old age and lastly death. Life span development begins between conception and child birth.

Characteristics of life span development.
Development is dependent on individuals as every individual has unique features.
Development is life long. Each life stage is continuous faced by varying challenges which vary from one individual to another thus there is no age period that is supreme or multidimensional. According to Boyd and Bee (2006), various characteristics set stage for the new born baby as the genetic program without body cell unfolds as the baby emerges in the world. The growing child is also influenced by the world surrounding them leading to alteration in the genetic expression. Development is multidirectional. This means that development is affected by decline or continuous growth.

 Development is plastic and also dynamic. According to Baltes (2006), human beings have the ability to change positively during environmental difficulties in life. Thus they learn modes of compensation and overcoming difficult periods. Baltes, Reese and Lipsett (1980) define genetic and neuronal plasticity as identification of potentialities based on the neuronal development and genetic expression level this includes other parts of the body and structural features of the brain. There is also societal plasticity which refers to differences in the environment and social contexts. This includes social class, ethnicity or migration. Lastly there is behavioral plasticity which is study of psychological functions and characteristics related to levels of learning or research on rate.

Development is contextual in that human development takes place in accordance to the events in their lives and the timing of those events can determine the development of such individuals. Development contextual therefore leads to shaping of an individuals career, way of life and development. Human beings are mostly vulnerable during transition periods from one age group to another. This is so especially if these transitions take place early or are not anticipated.

Development is multidisciplinary and as a result, development entails all the three domains socioeconomic, cognitive and biological and in order for one to be fully developed all the three domains must be functional. There are other disciplines that also contribute heavily to development. These include the political and social environment and the community at large. Development involves growth, maintenance and regulation. Changes taking place in an individual must be interpreted depending on the causes of those changes and the culture. Importance of human development is linked to the understanding of other disciplines and thus modifications taking place in adults is as important as those modifications taking place in childhood. Development is contextual meaning that development proceeds from what is already there thus improving on what we already are.
                                         
Development Domains
Development domains are classes or categories used by scientists. There are three development domains Biological domain involves growth, bodily changes and maturation. Biological domain is also referred to as physical domain which are changes that take place in humans physically especially from childhood to adolescence. Cognitive domain takes place mentally through knowing thus reasoning, perceiving and problem solving as well as imagining occurs (Blumberg and Lori 2004).

 This shows how learning takes place and explains why memory fades or deteriorates as one continues to age. This includes collecting information, sorting the information out thus the data is used to reason and develop thinking skills. Cognitive development has various areas which includes reasoning, information processing, memory, language development and intelligence (Blumberg and Lori 2004).

 Psychological domain entails expectations, emotions, social interactions and personality. This social domain is adjustable depending on the social stratification and social skills and in cases such as developing relationship. According to Boyd and Bee (2006), the above three domains operate together thus affect each other.

Human development ranges from conception to death or end of life. The periods are prenatal, early childhood, middle childhood, late childhood, adolescence early adulthood, middle adulthood and late adulthood. Prenatal human development is also referred to as antenatal development meaning gestation of the foetus from fertilization until birth during pregnancy. This is commonly referred to as fetal development or embryology. Embryo development or embryogenesis starts after fertilization. During the second trimester, hands and feet are well formed, sebaceous glands are formed and sweat glands and they start functioning. Taste buds, eyes and tongue and mouth are completely formed. During the third and the last trimester, the fetus is fully developed and its eventually expelled from the mothers womb.

 Early childhood. Child development vary from one child to another however all children undergo cognitive, emotional and physical or biological growth. By the time children are about 8 to 10 months, they develop fear due to threats. They also show anxiety when separated from the people they are familiar with (Blumberg and Lori 2004).

Middle childhood. (Children of ages 6-8 years old). These children develop social skills as they interact with the world as they join schools thus mental, physical and social skills develop rapidly. They also become confidence through sports friends and schoolwork. Late childhood. (Ages 10-12).during this period children develop rapid transition from childhood to adolescence. There are noticeable changes do begin to occur as after the age of 13. The children have difficulty with their body image and social skills (Blumberg and Lori 2004).

Adolescence. (Ages 13-19) Adolescence is characterized by sexual maturation, and physical growth. Boys tend to develop slower as compared to girls. They develop sense of identity, independence and ability to make decisions there is also heightened sexual interest. Early adulthood. Early adulthood commences from twenty years to thirty five years. Human beings at this stage are generally in good health and are very active and productive.

Middle adulthood. Middle adulthood is the period between thirty five and fifty five years. This is the period where human beings are most productive. Though aging differs from one person to another, some changes seem to take place in almost all human beings these include loss of skin elasticity, heart rate decreases, strength deteriorate with age. Natural fertility in women ends as menopause takes place during this phase. Late adulthood. Late adulthood is also referred to as old age whereby it is associated with decline of physical. Socioemotional and cognitive faculties. Physically the individuals become deaf, toothless, balding, and lameness. Sexual performance also declines. Sense of smell and taste also decreases. Low stomach acid production .thus there is increased weakness gradually leading to death
Contemporary Concerns Related To Life Span Development

There are various contemporary concerns related to life span development. These include Continuity and discontinuity. Boy and Bee (2006), points out that lifespan development whether changes occurring due to age are as a result of types or kinds. Children progress throughout various stages in life gradually, thus this continuity is viable to change. As a child progresses, the friends change, they develop other habits.

The other major controversy is whether the lifespan of a human being is influenced by the genetics or environment, thus the issue lies in whether the lifespan development of a human being depends on ones genetic make up or its under the influence of the surroundings. Thus is development controlled by nature or nurture While human beings changes are as a result of experiences and genetic factor, every individual is unique in genetic phenotype such as personality, physical characteristics, intelligence and genetic disorders.

Conclusion
Darwin began Lifespan development and it still intrigues both psychologists and scientists today human development domains occur throughout all the periods of human development. However human beings change or develop with age.