This chapter discusses the indicators of normal and abnormal physical, cognitive, emotional, and sexual development throughout the lifespan. Because growth and development are generally predictable, social workers should know the milestones of healthy development and the signs of potential delay or disability. The chapter presents the theories of sexual development, spiritual development, and racial, ethnic, and cultural development throughout the lifespan. It discusses the effects of physical, mental, and cognitive disabilities throughout the lifespan, the interplay of biological, psychological, social, and spiritual factors, and the principles of attachment and bonding. The chapter then discusses the effect of aging on biopsychosocial functioning, the impact of aging parents on adult children, parenting skills and capacities, the effects of addiction and substance abuse on individuals, families, groups, organizations, and communities, and the factors influencing self-image (e.g., culture, race, religion/spirituality, age, disability, trauma). It ends with discussion of psychoanalytic and psychodynamic approaches.