KEY THEME

Tests to measure and evaluate personality fall into two basic categories: projective tests and self-report inventories.

KEY QUESTIONS

When we discussed intelligence tests in Chapter 7, we described the characteristics of a good psychological test. Beyond intelligence tests, there are literally hundreds of psychological tests that can be used to assess abilities, aptitudes, interests, and personality (Spies & others, 2010). Any psychological test is useful insofar as it achieves two basic goals:

In this section, we’ll look at the very different approaches used in the two basic types of personality tests—projective tests and self-report inventories. After looking at some of the most commonly used tests in each category, we’ll evaluate the strengths and weaknesses of each approach.

Projective tests developed out of psychoanalytic approaches to personality. In the most commonly used projective tests, a person is presented with a vague image, such as an inkblot or an ambiguous scene, then asked to describe what she “sees” in the image. The person’s response is thought to be a projection of her unconscious conflicts, motives, psychological defenses, and personality traits. Notice that this idea is related to the defense mechanism of projection, which was described in TABLE 11.1 earlier in the chapter. The first projective test was the famous Rorschach Inkblot Test, published by Swiss psychiatrist Hermann Rorschach in 1921 (Hertz, 1992).

The Rorschach test consists of 10 cards, 5 that show black-and-white inkblots and 5 that depict colored ink-blots. One card at a time, the person describes whatever he sees in the inkblot. The examiner records the person’s responses verbatim and also observes his behavior, gestures, and reactions.

Numerous scoring systems exist for the Rorschach. Interpretation is based on such criteria as whether the person reports seeing animate or inanimate objects, human or animal figures, and movement, and whether the person deals with the whole blot or just fragments of it (Exner, 2007; Exner & Erdberg, 2005).

A more structured projective test is the Thematic Apperception Test, abbreviated TAT, which we discussed in Chapter 8. In the TAT, the person looks at a series of cards, each depicting an ambiguous scene. The person is asked to create a story about the scene, including what the characters are feeling and how the story turns out. The stories are scored for the motives, needs, anxieties, and conflicts of the main character and for how conflicts are resolved (Bellak, 1993; Langan-Fox & Grant, 2006; Moretti & Rossini, 2004). As with the Rorschach, interpreting the TAT involves the subjective judgment of the examiner.

STRENGTHS AND LIMITATIONS OF PROJECTIVE TESTS

Although sometimes used in research, projective tests are mainly used in counseling and psychotherapy. According to many clinicians, the primary strength of projective tests is that they provide a wealth of qualitative information about an individual’s psychological functioning, information that can be explored further in psychotherapy.

However, there are several drawbacks to projective tests. First, the testing situation or the examiner’s behavior can influence a person’s responses. Second, the scoring of projective tests is highly subjective, requiring the examiner to make numerous judgments about the person’s responses. Consequently, two examiners may test the same individual and arrive at different conclusions. Third, projective tests often fail to produce consistent results. If the same person takes a projective test on two separate occasions, very different results may be found. Finally, projective tests are poor at predicting future behavior.

The bottom line? Despite their widespread use, hundreds of studies of projective tests seriously question their validity—that the tests measure what they purport to measure—and their reliability—the consistency of test results (Garb & others, 2004; Weiner & Meyer, 2009). Nonetheless, projective tests remain very popular, especially among clinical psychologists (Butcher & Rouse, 1996; Leichtman, 2004).

Self-report inventories typically use a paper-and-pencil format and take a direct, structured approach to assessing personality. People answer specific questions or rate themselves on various dimensions of behavior or psychological functioning. Often called objective personality tests, self-report inventories contain items that have been shown by previous research to differentiate among people on a particular personality characteristic. Unlike projective tests, self-report inventories are objectively scored by comparing a person’s answers to standardized norms collected on large groups of people.

The most widely used self-report inventory is the Minnesota Multiphasic Personality Inventory (MMPI) (Butcher, 2010). First published in the 1940s and revised in the 1980s, the current version is referred to as the MMPI-2. The MMPI consists of over 500 statements. The person responds to each statement with “True,” “False,” or “Cannot say.” Topics include social, political, religious, and sexual attitudes; physical and psychological health; interpersonal relationships; and abnormal thoughts and behaviors (Delman & others, 2008; Graham, 1993; McDermut & Zimmerman, 2008). Items similar to those used in the MMPI are shown in TABLE 11.6.

The MMPI is widely used by clinical psychologists and psychiatrists to assess patients. It is also used to evaluate the mental health of candidates for such occupations as police officers, doctors, nurses, and professional pilots. What keeps people from simply answering items in a way that makes them look psychologically healthy? Like many other self-report inventories, the MMPI has special scales to detect whether a person is answering honestly and consistently (Butcher, 2010; Pope & others, 2006). For example, if someone responds “True” to items such as “I never put off until tomorrow what I should do today” and “I always pick up after myself,” it’s probably a safe bet that she is inadvertently or intentionally distorting her other responses.

The MMPI was originally designed to assess mental health and detect psychological symptoms. In contrast, the California Psychological Inventory and the Sixteen Personality Factor Questionnaire are personality inventories that were designed to assess normal populations (Boer & others, 2008; Megargee, 2009). Of the over 400 true–false items on the long version of the California Psychological Inventory (CPI), nearly half are drawn from the MMPI. The CPI provides measures on such characteristics as interpersonal effectiveness, self-control, independence, and empathy. Profiles generated by the CPI are used to predict such things as high school and college grades, delinquency, and job performance (see Crites & Taber, 2002).

The Sixteen Personality Factor Questionnaire (16PF) was originally developed by Raymond Cattell and is based on his trait theory. The 16PF uses a forced-choice format in which the person must respond to each item by choosing one of three alternatives. Just as the test’s name implies, the results generate a profile on Cattell’s 16 personality factors. Each personality factor is represented as a range, with a person’s score falling somewhere along the continuum between the two extremes (see FIGURE 11.4). The 16PF is widely used for career counseling, marital counseling, and evaluating employees and executives (H. E. P. Cattell & Mead, 2008; Clark & Blackwell, 2007).

Another widely used personality test is the Myers–Briggs Type Indicator (abbreviated MBTI). The MBTI was developed by Isabel Briggs Myers and Katharine Cook Briggs (see Gladwell, 2004; Quenk, 2009). Myers and Briggs were intrigued by Carl Jung’s personality theory and his proposal that people could be categorized into discrete personality “types.” The Myers–Briggs test differs from other self-report tests in that it is designed to assess personality types rather than measure personality traits.

The notion of personality types is fundamentally different from personality traits. According to trait theory, people display traits, such as introversion/extraversion, to varying degrees. If you took the 16PF or the CPI, your score would place you somewhere along a continuum from low (very introverted) to high (very extraverted). However, most people would fall in the middle or average range on this trait dimension. But according to type theory, a person is either an extrovert or an introvert—that is, one of two distinct categories that don’t overlap (Arnau & others, 2003; Wilde, 2011).

The MBTI arrives at personality type by measuring a person’s preferred way of dealing with information, making decisions, and interacting with others. There are four basic categories of these preferences, which are assumed to be dichotomies—that is, opposite pairs. These dichotomies are: Extraversion/Introversion; Sensing/Intuition; Thinking/Feeling; and Perceiving/Judging.

There are 16 possible combinations of scores on these four dichotomies. Each combination is considered to be a distinct personality type. An individual personality type is described by the initials that correspond to the person’s preferences as reflected in her MBTI score. For example, an ISFP combination would be a person who is introverted, sensing, feeling, and perceiving, while an ESTJ would be a person who is extroverted, sensing, thinking, and judging.

Despite the MBTI’s widespread use in business, counseling, and career guidance settings, research has pointed to several problems with the MBTI. One problem is reliability—people can receive different MBTI results on different test-taking occasions. Equally significant is the problem of validity. For example, research does not support the claim of a relationship between MBTI personality types and occupational success (Pittenger, 2005). More troubling is the lack of evidence supporting the existence of 16 distinctly different personality types (Hunsley & others, 2003). Thus, most researchers in the field of psychological testing advise that caution be exercised in interpreting MBTI results, especially in applying them to vocational choices or predictions of occupational success (see Pittenger, 2005).

STRENGTHS AND LIMITATIONS OF SELF-REPORT INVENTORIES

The two most important strengths of self-report inventories are their standardization and their use of established norms (see Chapter 7). Each person receives the same instructions and responds to the same items. The results of self-report inventories are objectively scored and compared to norms established by previous research. In fact, the MMPI, the CPI, and the 16PF can all be scored by computer.

As a general rule, the reliability and validity of self-report inventories are far greater than those of projective tests. Literally thousands of studies have demonstrated that the MMPI, the CPI, and the 16PF provide accurate, consistent results that can be used to generally predict behavior (Anastasi & Urbina, 1997).

However, self-report inventories also have their weaknesses. First, despite the inclusion of items designed to detect deliberate deception, there is considerable evidence that people can still successfully fake responses and answer in socially desirable ways (Anastasi & Urbina, 1997; Holden, 2008). Second, some people are prone to responding in a set way. They may consistently pick the first alternative or answer “True” whether the item is true for them or not. And some tests, such as the MMPI and CPI, include hundreds of items. Taking these tests can become quite tedious, and people may lose interest in carefully choosing the most appropriate response.

Third, people are not always accurate judges of their own behavior, attitudes, or attributes. And some people defensively deny their true feelings, needs, and attitudes, even to themselves (Cousineau & Shedler, 2006; Shedler & others, 1993). For example, a person might indicate that she enjoys parties, even though she actually avoids social gatherings whenever possible.

To sum up, personality tests are generally useful strategies that can provide insights about the psychological makeup of people. But no personality test, by itself, is likely to provide a definitive description of a given individual. In practice, psychologists and other mental health professionals usually combine personality test results with behavioral observations and background information, including interviews with family members, co-workers, or other significant people in the person’s life.

Over the course of this chapter, you’ve encountered firsthand some of the most influential contributors to modern psychological thought. As you’ll see in Chapter 15, the major personality perspectives provide the basis for many forms of psychotherapy. Clearly, the psychoanalytic, humanistic, social cognitive, and trait perspectives each provide a fundamentally different way of conceptualizing personality. That each perspective has strengths and limitations underscores the point that no single perspective can explain all aspects of human personality. Indeed, no one personality theory could explain why Kenneth and Julian were so different. And, given the complex factors involved in human personality, it’s doubtful that any single theory ever will capture the essence of human personality in its entirety. Even so, each perspective has made important and lasting contributions to the understanding of human personality.