Major Stages of Human Psychological Development

Major Stages of Human Development

Developmental psychology is the scientific study of changes in the human individual from birth through old age. The developmental process is a continuous journey; significant changes in personality and psychological traits occur throughout distinct life stages, including adolescence, adulthood, and old age.

Key Theories of Psychological Development

• Sigmund Freud: Studied the evolution of sexuality in children and its impact on personality and social relations. He proposed that children move from primary narcissism to channeling sexual impulses toward others. Genital sexuality develops in two phases: the first from ages 1 to 4-5 (Oedipus complex) and the second during puberty following the latency period.
• Jean Piaget: Focused on intellectual development by investigating how mental models interact with environmental data. Children progress from feeling and manipulating objects to forming mental representations. This involves the ability to group and classify objects, replace perceived objects with symbols, and conform to rules and principles of logic.
• Erik Erikson: Proposed that personality and the self are adjusted through social interaction across eight distinct stages:
  • Newborn (Oral): Trust versus mistrust.
  • Children 1 to 3 years (Anal stage): Autonomy versus shame.
  • Children 3 to 6 years (Phallic phase): Initiative versus guilt.
  • Children 6 to 12 years (Latency phase): Diligence versus inferiority.
  • Adolescents (Genital stage): Identity versus confusion.
  • Young Adult: Intimacy versus isolation.
  • Adult: Productivity versus stagnation.
  • Elder: Integration versus despair.

Moral Development Theories

• Lawrence Kohlberg: Investigated the evolution of moral reasoning—how individuals determine right from wrong. He identified three basic levels of moral evolution:
  • Preconventional Level: Good is defined by rewards, while wrong is defined by what causes harm.
  • Conventional Level: Moving beyond selfishness to understand social norms through social exchange.
  • Post-conventional Level: The stage of abstract moral principles, which often transcend legal enforcement.