Erikson's theory of ____________development involves a series of eight stages, each of which must be resolved for a person to develop optimally.

Erik Erikson's theory of psychosocial development is a cornerstone of human development psychology. It posits that individuals pass through eight distinct stages over the course of their lifetime. Each stage is characterized by a specific conflict that the individual must resolve to advance optimally in development.

Trust vs. Mistrust

The first stage occurs between birth and approximately 18 months of age. Infants learn to trust their caregivers for basic needs. Successful resolution leads to a sense of security, while failure results in fear and a belief that the world is inconsistent and unpredictable.

Autonomy vs. Shame and Doubt

Between 18 months to approximately 3 years, children work on developing a greater sense of personal control. They learn to exert independence, if encouraged, or may develop shame and doubt about their abilities if not supported.

Initiative vs. Guilt

From 3 to 5 years, children begin to assert power and control over the world through directing play and social interactions. Success leads to a sense of purpose, while failure results in a sense of guilt.

Erikson's model of psychosocial development represents the growth of an individual's ability to interact with others and to understand oneself within a social context. The 'psycho-' aspect of the theory refers to the internal, psychological factors of personality, while the '-social' aspect refers to the relationships and cultural demands that influence one’s development.

Each stage involves a psychosocial crisis of two conflicting forces. These are essential for cultivating skills and traits that are valued by society. For instance, learning to trust others lays the groundwork for healthy relationships. In contrast, failing to resolve these crises can result in feelings of inadequacy. Erikson's theory emphasizes that these stages are not discrete: challenges of earlier stages can reappear as issues in later stages.

Human development psychology is a field that explores how people change over the course of their life, from conception to death. It seeks to understand how and why people change or remain the same over time. Erikson’s theory fits into this branch of psychology by providing a framework for the changes in social relationships and the self that occur with physiological maturation.

One pivotal concept in Erikson’s psychosocial development theory is the 'epigenetic principle,' which suggests that human development follows a sequence where each stage builds upon the previous one. This sequence leads to the strengthening or weakening of individual traits or behaviors—effectively shaping the personality and social behaviors. Professionals in this field use such theories to understand conflicts at various life stages and to devise strategies for overcoming challenges to achieve psychological well-being.