What is Normal?
There are several criteria for judging whether people's thinking, emotions, or behaviors are normal. But to explain clearly what is normal, we must find out what is abnormal. Abnormal is thought, behavior, feelings which are maladaptive, disruptive, uncomfortable to person those they are in relationship with. It is known by consequences that include losing control over action, thought, emotion in personal, social, or work life. If we define normality as what most people do, an obvious criterion for abnormality is statistical infrequency, that which is atypical or rare. Another criterion for abnormality is personal suffering and norm violation. Because no single criterion is entirely adequate for identifying abnormality, mental health practitioners and researchers tend to adopt a practical approach that combines aspects of all the criteria. This practical approach pays special attention to whether a person's thoughts, behavior, or emotions cause impaired functioning - that is, difficulty in fulfilling appropriate and expected social roles.
Also, normal people are people that are not suffering from psychological disorders. In spite of differing definitions of abnormality within and across cultures, there does seem to be a set of behavior patterns that roughly defines the range of most abnormality in most cultures. In 1952 the American Psychiatric Association published the first edition of what has become the "official" North America diagnostic classification system, the Diagnostic and Statistical Manual of Mental Disorders (DSM). The latest edition, DSM-IV, contains more than three hundreds specific diagnostic labels. It can evaluate a person on five dimensions. The clinical syndromes, personality or development disorders, physical disorders, psychosocial stressors, and adaptive functioning assessment.
Some examples from DSM-IV are anxiety disorders, somatoform disorder, dissociative disorders, person...