Key Points

Development is the pattern of progressive, orderly, and predictable changes that begin at conception and continue throughout life. It involves both growth, which is a measurable increase in size, and decline.

This perspective views development as lifelong, multi-directional, plastic (modifiable), and influenced by historical and cultural contexts. It is a dynamic interplay of biological, cognitive, and socio-emotional processes.

Growth is the quantifiable increase in body size. Maturation refers to genetically programmed, orderly changes. Evolution refers to species-specific changes passed through generations.

Genotype is an individual's actual genetic heritage inherited from parents. Phenotype is the observable and measurable expression of the genotype, such as height, eye color, and intelligence.

This model describes development within nested environmental systems: Microsystem (immediate surroundings), Mesosystem (connections between microsystems), Exosystem (indirect influences), Macrosystem (culture), and Chronosystem (life events over time).

Motor development follows two trends: cephalocaudal (from head to tail) and proximodistal (from the center of the body outwards). Newborns possess innate reflexes like rooting and grasping for survival.

Attachment is the strong emotional bond between an infant and their caregiver. Harlow's research highlighted the importance of 'contact comfort' over just feeding in forming this bond.

Infants understand the world through sensory experiences and motor actions. The key achievement is object permanence, the understanding that objects continue to exist even when they cannot be seen.

Children in this stage use symbolic thought but are limited by egocentrism (inability to see others' perspectives), animism (believing inanimate objects are alive), and centration (focusing on only one aspect of a situation).

Children develop logical thinking about concrete events. They master conservation (understanding that quantity remains the same despite changes in appearance) and can perform reversible mental operations.

Adolescents develop the ability for abstract, idealistic, and logical thought. They can engage in hypothetical-deductive reasoning, which involves systematically thinking about problems and potential solutions.

Lawrence Kohlberg proposed that moral reasoning develops through age-related stages. It progresses from decisions based on external authority (punishment and reward) to decisions based on internalized, personal moral principles.

Adolescence is the transition from childhood to adulthood, beginning with puberty. Puberty involves rapid physical growth and the development of primary (reproductive) and secondary (non-reproductive) sexual characteristics.

According to Erik Erikson, the primary developmental task of adolescence is forming a stable sense of identity. Failure to achieve this can lead to identity confusion and uncertainty about one's role in life.

David Elkind identified two features of adolescent egocentrism: the imaginary audience (belief that others are constantly observing them) and the personal fable (a sense of being unique and invincible).

Adolescents may face challenges such as delinquency, substance abuse (drugs, alcohol, smoking), and eating disorders like anorexia nervosa and bulimia, often influenced by peer pressure and stress.

Early adulthood involves focusing on career, work, marriage, and parenthood. Middle adulthood is often marked by gradual physical decline, while cognitive abilities like wisdom may increase.

Key challenges for the elderly include adjusting to retirement, widowhood, illness, and increasing dependency. Successful aging is influenced by health, social support, and maintaining a sense of purpose.