Erickson's Psychosocial Stages
Piaget's Cognitive Stages

Developmental Stages

Erickson provides a theory of human growth and development in terms of psychological and social stages. Erickson's theory is a "step" theory, where each stage is consecutively entered, a psychological crisis is encountered and must be resolved successfully to ensure success in future stages. ADHD tends to be a lifelong struggle and therefore affects all stages. For the purposes of this site, we will discuss the stages of Middle Childhhood (ages 6-12) and Early Adolescence (12-18), in terms of peer rejection and social difficulties (APA, 2000; Guevremont & Dumas, 1994). For a more in-depth discussion of Erickson's theory see this discussion of the Psychosocial Stages.

Piaget's theory describes the development of cognitive thought in terms of consecutive stages. Each stage describes a different level of logical, rational , and complex thought processes, with each stage becoming more and more abstract, handling more variables, and increased abilities to take different perspectives. Piaget's theory contains four stages, we will focus on the third and fourth stages: Concerte and Formal Operational Stages. A more thorough discussion of Piaget's theory on cognition is available here.