The use of personality tests is ubiquitous in contemporary society; the personality testing industry is a $400 million industry (1). Personality tests have been used by both large and small institutions, including schools, corporations, and hospitals, to sort, classify, categorize, and assign diagnoses to people. References to personality tests and other forms of institutional control have even made their way into books and movies. An example is how the legendary wizard Harry Potter was placed into the Gryffindor House at the Hogwarts School of Witchcraft and Wizardry by a "sorting hat" that could gauge the temperament of each student (2). Professionals who work in the mental health and addiction fields are likely to be familiar with some of the types of personality tests applied in child custody hearings, forensic and other clinical diagnostic evaluations, and screening assessments in schools.

Personality tests are often considered benign. Until now there has been a dearth of work examining the cultural history of personality tests, the development of the tests, and how the tests are administered and regulated. Annie Murphy Paul, the author of The Cult of Personality: How Personality Tests Are Leading Us to Miseducate Our Children, Mismanage Our Companies, and Misunderstand Ourselves, is uniquely equipped to explore such issues on the basis of her experience as a journalist covering mental health and psychology for a variety of mainstream publications. Although the intended audience is a general readership, the book will be useful for a variety of professionals, including managers, psychologists, and other mental health professionals and educators.

The book is well written and traces the cultural history behind the development of many of the most widely known personality tests, including the Rorschach inkblot test, the Minnesota Multiphasic Personality Inventory, the Thematic Appreciation Test, and the Myers-Briggs Type Indicator. In addition, it touches on some of the emerging trends in personality testing, such as functional magnetic resonance imaging (fMRI) and computer-enabled personality tests. Throughout the book, the author critically evaluates the uses, misuses, strengths, and weaknesses of each of the tests specifically, as well as with personality tests in general.

Some of the author's conclusions are particularly startling, including the fact that the personality testing industry is, for the most part, unregulated and that many personality tests are administered by untrained and unqualified personnel. However, perhaps the most striking conclusion is that personality tests are overly reductionistic and neglect to account for the context, situation, and environment in which an individual lives and works. Herein lies the danger to personality tests: "People are too erratic and complex to be so pigeonholed" (3) by tests that reduce complex personality traits into narrow, one-dimensional labels. Although this conclusion should not surprise most Psychiatric Services readers, considering the pervasiveness of the biopsychosocial approach to the diagnosis and treatment of psychiatric disorders, it should sound an alarm for anyone who administers personality tests, anyone who interprets the results of personality tests in clinical decision making, and, most important, those who are subjected to a personality test. Most, if not all, ordinary individuals who are subjected to personality tests either as a condition of employment or as mandated by court order are powerless to protect themselves from the damage of being condemned to a one-dimensional label. Despite the evidence that many personality tests lack reliability and validity, they are unlikely to disappear from use in corporations, courts, schools, and other institutions in the near future. The take-home point, therefore, is caveat emptor (buyer beware).

Mr. Provost is affiliated with the alcohol and drug abuse treatment program at McLean Hospital in Belmont, Massachusetts.