This document discusses the definitions of normal and abnormal behavior in psychology. It notes that to assess and treat abnormal behavior, clear definitions are needed. Abnormal behavior is defined as deviating from the norm. However, defining normal human functioning is difficult since there is no agreed upon model. The document outlines two views on what defines abnormal - deviation from social norms, and maladaptive behavior that interferes with optimal functioning. It concludes by thanking the reader for their attention.