A child will create and construct a personal reality from relationships, interactions, and events in his or her life. This book relies heavily on applying the leading developmental theories to child development. It talks about dramatic changes in physical, cognitive, and emotional development take place monthly during infancy, every six months in early childhood, and yearly in middle childhood. The book provides the mental health professional with condensed handout versions of the information offered for each age. A child's development will be limited if he or she experiences certain events or environments. Therapists will recognize the traditional developmental models employed in this book to help to describe each age of childhood. A person's identity or personality is created throughout all stages and is not fixed within one period of development. Jane Loevinger described the ego as the internal structure that organizes and gives meaning to experiences of the person.