| Evaluating the MMPI in Legal Cases | | | Laquetta Cheeks | 2/9/2013 |

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Personality assessment instruments are used every day for different things, such as an occupation, clinical studies, and educational program. Personality can be defined as an individual’s combination of personality traits or characteristics that determines one’s persona. According to Cohen and Swerdlik (2010), “personality assessment may be defined as the measurement and evaluation of psychological traits, states, values, interests, attitudes, worldwide, acculturation, personal identity, sense of humor, cognitive and behavior styles, and related individual styles”. The purpose of these particular instrument include finding a suitable occupation for an individual’s personality type, identifying learning disabilities among children in grade school, assessing and diagnosing individuals with a mental disorder. An example of a personality assessment instrument will be the MMPI or the Minnesota Multiphasic Personality Inventory, which will be the particular instrument discussed within this paper.
MMPI
The Minnesota Multiphasic Personality Inventory (MMPI) was developed in 1939 by Starke Hathaway and J. C. McKinley. The purpose of this particular assessment test is to identify individuals with a psychological issue or deterred mental health. According to Cohen and Swerdlik (2010), the MMPI contained 566 true or false questions and was designed as an aid to psychiatric diagnosis with adolescents and adults, which is based on logic and reasoning. This particular assessment test has 3 other versions, but the MMPI is the first and original version of the test. The latest version of the MMPI is the MMPI-2 RF, but the MMPI0-2 is the most commonly used version. Moreover, this test is commonly used in an occupation environment that requires Top Secret security clearance, such as the Department of Defense and the Central Intelligence Agency. It is also known to be administered for case purposes, such as criminal defense and custody disputes. The MMPI contains 10 scale items that tests individuals in different areas of psychological health.
The 10 scales of the Minnesota Multiphasic Personality Inventory included the hypochondriasis scale, the depression scale, the hysteria scale, the psychopathic deviate scale, the masculinity- femininity scale, the paranoia scale, the psychasthenic scale, the schizophrenia scale, the hypomania scale, and the social introversion scale. Each scale contained different test items and different amount of questions asked within the questionnaire. For example, the depression scale contained 57 test items that evaluated an individual’s unhappiness and attitude about their future. (Cohen & Swerdlik, 2010) The schizophrenia scale contained 78 test items which evaluated an individual’s thinking process and social interactions. Moreover, the paranoia scale contained 40 test items which evaluated a person’s suspiciousness, ideas of reference, delusions of persecution, and delusions of grandeur. (Cohen & Swerdlik, 2010)
Behavioral Theory
To better understand the nature of the MMPI, one must get an understanding of the personality theory. The theory of personality that is most suitable for this particular assessment test will be behavioral personality theory because majority of the scale items are based on an individual’s behavior and attitude. The behavioral theory of personality focuses on the individual’s attitude and interactions and the environment that the individual is exposed to. According to Moore (2011), B. F. Skinner was a well-known behavior theorist that focused on classical conditioning and operant conditioning to develop his theory. (pg. 452) Operant conditioning is a method used in psychology to study an individual’s behavior, which involves the reward and punishment system. A definition for operation was defined by P. W. Brigman. (Moore, 2011, pg. 452) Skinner believed that an