DEFINITION OF ABNORMAL PSYCHOLOGY Abnormal psychology is the branch of psychology that studies unusual patterns of thoughts, feelings and behavior. CRITERIA FOR DEFINING ABNORMAL PSYCHOLOGY The criteria for defining abnormal psychology/ behavior include: 1. Personal distress: subjective experience of emotional suffering (e.g., anxiety, depression) 2. Statistical rarity: has unusual behaviors (e.g., binge eating), IQ way above or below the average 3. Maladaptive behavior: has impaired functioning (e.g., insomnia). There is difficulty in carrying out everyday functions (e.g., work, maintaining relationships) in an adaptive manner. Under this definition, a person is considered abnormal if they are unable to cope with the demands of everyday life. They may be unable to perform the behaviors necessary for day-today living e.g. self-care, hold down a job, interact meaningfully with others. Rosenhan & Seligman (1989) suggested the following characteristics that define failure to function adequately: