The Eysenck Personality Questionnaire is the result of the work of Sybil B. G. Eysenck and Hans Jürgen Eysenck. It is a personal assessment based around the idea that certain portions of an individual's personality are largely genetic, rather than being learned throughout a lifetime. The Eysenck Personality Questionnaire, also abbreviated as EPQ, is designed to assess these relatively stable traits. It was originally designed with just two broad categories: extroversion or introversion, and neuroticism or stability. Over time, the EPQ was modified to add a third category, psychoticism or socialization. Many free versions of this test are available online, and certain psychologists may still give them to patients, though this is less common.
Each one of the three large categories in the Eysenck Personality Questionnaire is designed to measure a series of smaller personality traits. For instance, a person who is extroverted might describe himself or herself as being talkative, social, and someone who enjoys being in large groups. An introvert may be uncomfortable in large groups, may be a much quieter or more reserved person, and enjoy being alone. The introversion/extroversion determination is found in a wide variety of personality assessments, not just the EPQ, since it is thought to be one of the most stable across a person's life.
The neuroticism/stability categories and psychoticism/socialization categories are divided similarly. A person who falls on the "neurotic" side of the spectrum may be more prone to anxiety and getting upset in certain situations, and have less ability to control their emotions, while a person who is more stable will be able to control his or her responses more, and will be less likely to get anxious. A high score in the psychoticism indicator does not necessarily indicate a higher risk factor for psychosis; more generally, it just indicates a person who may be more aggressive or egocentric than others.
Typically, the Eysenck Personality Questionnaire is designed with a set number of questions, each of which has a simple yes or no answer, rather than more complex quizzes that may force people to choose from a spectrum of answers. There are a number of different personality traits that can be assessed from this quiz; for instance, introversion, neuroticism, and socialization may all be combined into one personality, or any other combination of the three. All of these will then suggest different traits that may dictate a person's behavior throughout his or her life. Perhaps not surprisingly, significant disagreement exists between psychologists regarding the reliability and practical applications of this particular test in comparison to other methods of personality assessment.