11.6 Personality Assessment

Is It Legit? Reliability and Validity

Before we discuss the various types of personality tests, let’s get a handle on the qualities that render these tests effective—reliability and validity. Reliability can refer to two aspects of an assessment. Test–retest reliability is how consistent results are when the same person takes the test more than once. Suppose you take the same personality test today and tomorrow. From one day to the next, your personality is unlikely to change, so your results shouldn’t either. With a reliable test, the scores should be very similar at different points in time. Interrater reliability refers to the consistency across people scoring an assessment. With high interrater reliability, the results are the same regardless of who scores the test.

The other important quality of a personality assessment is validity. A valid measure is one that can be shown to measure what it intends to measure. Let’s say a psychologist develops an assessment for extraversion. In order for her test to be considered valid, it must yield results that are similar to already established and valid assessments of extraversion.

Assessment of personality can be broadly classified into objective and subjective measures. Findings from subjective assessments are based, in part, on personal intuition, opinions, or interpretations. With objective assessments, findings are based on a standardized procedure in which the scoring is free of opinions, personal beliefs, expectations, and values. Critics of subjective assessments suggest that there is not enough consistency across findings, as a result of nonstandard scoring procedures. And as noted in earlier chapters, humans are prone to a variety of biases and cognitive errors that can interfere with our ability to make useful assessments of people and situations. Critics of objective assessments challenge the standardized nature of objective testing because it does not allow for flexibility or fully appreciate individual differences in experiences. Despite these alleged flaws, many psychologists use a mixture of objective and subjective assessment techniques with their clients.

Not everyone agrees about the effectiveness of personality assessment. Even so, they are used in many contexts and in ways that have profound implications. Psychologists use personality tests to get to know their clients and diagnose mental disorders. Companies use them to make decisions about new hires and promotions (Does this person have what it takes to be a manager?). Personality tests are part of the battery of assessments used to evaluate the functioning of parents embroiled in custody disputes: Is mom depressed? Can she care for this child? (Lilienfeld, Wood, & Garb, 2005).

In this next section, we will explore the major types of personality tests that psychologists employ: interviews, projective personality tests, and objective personality tests. Many of these are aligned with specific perspectives (psychoanalytic or behavioral, for example) but most psychologists use an integrative approach, drawing on multiple perspectives in their assessment of clients.

What Brings You Here Today?

Tell Me About Yourself Psychologists assess personality using a variety of tools, including personal interviews. These face-to-face sessions range from open-ended and exploratory to highly structured.

Niko Guido/Getty Images

One way to gather information about personality is through a face-to-face interview. In an unstructured, or open-ended, interview, there is no predetermined path. A psychologist might begin with a question like, “What brings you here today?” and then gently direct the conversation in a way that helps her understand her client’s strengths and weaknesses, hopes and plans. Semistructured and structured interviews, on the other hand, employ specific paths of questioning that hinge on the respondent’s answers. This format provides a more systematic means of comparing behaviors across individuals.

One great advantage of the interview is that it allows a psychologist to see a client in a relatively natural, realistic setting. Talking with a client face-to-face, a psychologist can observe facial expressions and body language, which may offer clues to what’s going on inside. There are drawbacks, however. Interview subjects may lie to the interviewer (without even realizing it), spin the facts to misrepresent themselves, or share memories that are distorted or incomplete. Another source of error is the interviewer. She may, for example, lead the interview in a particular direction or interpret responses in a way that reinforces her own beliefs about personality. Clients can also be influenced by the interviewers’ nonverbal language. The desire to answer “correctly” is strong in an interview format. Just as in surveys, the way a question is asked can have a profound influence on the answer.

What Do You See? Projective Personality Tests

It’s a hot summer’s day and you’re lying on the beach, gazing at the clouds. “What do you see?” you ask your friend. “I see the profile of a Doberman pinscher,” she replies. “That’s funny,” you say. “I see a child doing jumping jacks.”

How is it possible that two people can look at the same image and come away with such different impressions? Some would argue that it has a lot to do with personality. The idea that personality influences perception is the premise of projective personality tests, which psychologists use to explore characteristics that might not be accessible through interview or observation, as they attempt to access aspects of the unconscious (Infographic 11.3.). With this type of assessment, the test taker is shown a stimulus without a specified meaning and then prompted to project meaning onto it. Projective personality tests assume that people carry around anxiety and unresolved conflicts, often beneath conscious awareness. Because these tests attempt to uncover such issues indirectly, they are less threatening than other methods, and therefore provoke less resistance. The goal of the test administrator is to take the manifest content (what the person reports seeing) and try to understand its underlying meaning.

INFOGRAPHIC 11.3: Examining the Unconscious: Projective Personality Tests

The psychoanalytic perspective holds that some aspects of personality exist beneath conscious awareness. Projective personality tests seek to uncover these characteristics. Ideas and anxieties in the unconscious will appear in descriptions of ambiguous stimuli, revealing previously hidden conflicts that the test administrator can evaluate.

Credits: Various black and white picture cards depicting an emotional situation, for the Thematic Apperception Test (TAT), © Spencer Grant/PhotoEdit — All rights reserved; Rorschach-Inkblot-Test Sheila Terry/Science Source

The most well-known projective personality test is the Rorschach. The original version of the test was developed by Swiss psychiatrist Hermann Rorschach in 1921. Today’s psychologists typically use Rorschach inkblots with the comprehensive coding system introduced by John Exner in the 1970s (Exner, 1980, 1986).

Here is a rough description of how the test is administered: Imagine someone hands you a series of cards covered in odd-looking blotches of ink—five cards with black-and-white blotches, and another five with color. Presenting the cards one by one, he asks you to report what you see. The images you describe and the details on which you focus will be important factors in the assessment of your personality, which involves a systematic comparison with answers given by other test takers who have known personality characteristics and diagnoses. Do you see bears playing patty cake? Seeing animals in motion might be interpreted as a sign of rashness. Are you homing in on the black areas? This could suggest a feeling of melancholy or sadness (Lilienfeld et al., 2005).

In the mid-1930s, Henry Murray and his colleagues developed the Thematic Apperception Test (TAT), a projective test that consists of 20 cards containing black-and-white illustrations of ambiguous scenes. When shown a card, the test taker is asked to tell a story about it. The story might incorporate a description of the people in the scene, and should include what led up to the scene, the emotions and thoughts of the characters, and the conclusion of the story. The assumption is that the test taker will project underlying conflicts onto the ambiguous stimuli of the picture; the job of the test administrator is to unearth them.

Taking Stock: An Appraisal of Projective Personality Tests

One criticism of projective personality tests is that they can take too much time. However, because the test taker may be willing to speak openly, honestly, and freely due to the unstructured nature of the assessment, the benefits seem to outweigh the costs. Another major concern, mentioned earlier, is the subjectivity of interpreting the results, which can lead to problems with their reliability. Different test administrators might not arrive at similar scores, or when the assessment is given a second time to the same person, the results might be different. Even the comprehensive scoring system for the Rorschach inkblots has not resolved concerns about projective tests, because the issue of validity still remains. Many critics suggest projective tests are not valid because they do not measure what they claim to be measuring (Schultz & Schultz, 2013).

Nonetheless, projective tests are used by clinicians because they often provide a way to begin forming a picture of a client. Clinicians can use a multifaceted approach to understanding personality, administering projective tests in conjunction with interviews, observations, and objective assessments.

What tools do you use to get a feel for someone’s personality? Maybe you pay close attention to how they behave in social situations, or observe the ways they respond to stress. Do you ever try to size up someone’s personality by looking at his Facebook page? Believe it or not, this strategy may actually be effective. In some cases, personality characteristics projected through social media bear close resemblance to who people are in real life.

Dominique Deckmyn/www.CartoonStock.com

Objective Personality Tests

Earlier we mentioned that clinicians use a variety of tools to assess the personalities of their clients. Among those tools are objective personality tests, assessments made up of a standard set of questions with previously established answers (true/false, multiple choice, circle the number). These tests are called objective because the results are assessed in a standardized way, free of personal bias. In contrast to the projective inventories, which often seem to be overly subjective, objective personality tests have clear scoring instructions that are identical for anyone taking the test. Often scores are calculated by a computer. In addition to being convenient and unbiased, objective tests have a solid base of evidence supporting their reliability and validity (Anastasi & Urbina, 1997). Some of these tests may focus on a particular personality characteristic or trait (such as locus of control); others might assess a group of characteristics (such as the Big Five).

The most commonly used objective personality test is the Minnesota Multiphasic Personality Inventory (MMPI–2) (Butcher & Rouse, 1996). This self-report questionnaire includes more than 567 statements to which the individual responds “true,” “false,” or “cannot say.” Some of the items you might see on the MMPI–2 include statements such as “I often wake up rested and ready to go” or “I want to work as a teacher.” Since the original purpose of the MMPI was to identify disorders and abnormal behavior, it includes 10 clinical scales (such as hypochondriasis and depression). It also has validity scales (such as the Lie scale and the Defensiveness scale) to assess the degree to which the results are useful. The validity measures help ensure that the person taking the assessment is not trying to appear either more disturbed or more healthy than she actually is. Often the MMPI is used to inform decisions about custody or other legal issues, and in a variety of nonclinical settings. So, it is important to control for manipulation of the assessment by the test taker. Like other personality assessments, the MMPI has its share of criticisms. Since it was designed to help make diagnoses, many feel its application outside of therapeutic settings is inappropriate. The scales are based on groups exhibiting abnormalities, and therefore they may not translate to nonclinical populations.

Another objective assessment of personality is the Sixteen Personality Factor Questionnaire (16PF), originally created by Raymond Cattell and based on his trait theory of personality. With the 16PF, the test taker must select one of three choices (forced choices) in response to 185 questions. Ultimately, a profile is constructed, which indicates where the person falls along the continuum of each of the 16 dimensions. Take a look at Figure 11.5 and you can see how pilots and writers compare on the 16 factors. For example, airline pilots tend to fall on the tough-minded end of the continuum, whereas writers tend to be located on the sensitive, tender-minded end (Cattell, 1973a).

FIGURE 11.5Example Profiles Generated by the 16PFOn Cattell’s 16PF, writers appear to be more reserved, sensitive, and imaginative than airline pilots. Pilots, on the other hand, tend to fall on the tough-minded end of the continuum. Are you surprised that they also appear to be more relaxed?

Source: Cattell (1973b).

One very popular objective assessment of personality is the Myers–Briggs Type Indicator (MBTI) (Briggs & Myers, 1998). Katherine Briggs and her daughter Isabel Briggs-Myers created this assessment in the 1940s. It designates a personality “type” as it relates to the following four dimensions: extraversion (E) versus introversion (I); sensing (S) versus intuiting (N); thinking (T) versus feeling (F); and judgment (J) versus perception (P). For example, someone characterized as ISTP would be introspective, rely on the senses (rather than intuition) to understand the environment, and favor logic over emotion.

Problems arise when assessments incorporate somewhat vague descriptions of personality traits. Some would even liken this to the Barnum effect, which was named after P. T. Barnum, who was famous for his ability to convince people he could read minds. Essentially, he did this by making generally complimentary and vague statements that could be true about anyone (You are creative and work well with others and you sometimes procrastinate, but ultimately you get the job done). Similarly, with the MBTI, the personality type descriptions are “general flattering and sufficiently vague so that most people will accept the statements as true of themselves” (Pittenger 1993, p. 6). Although the MBTI is very popular, the research support for this objective assessment is weak, especially as it relates to job performance, career choices, and so forth (Pittenger, 2005). Because the test results don’t always correlate with job success, this puts into question the validity of the assessment. In addition, the test–retest reliability is not always strong. A person can take the test twice and end up with different results (Hunsley, Lee, & Wood, 2003; Pittenger, 2005).

Taking Stock: An Appraisal of Objective Personality Tests

We have noted specific criticisms of the MMPI and Myers–Briggs tests, but there are other serious drawbacks of objective assessments. Although many of the objective tests include some sort of mechanism for checking the validity of the test taker’s answers, people may lie (and get away with it), particularly when the assessment results may impact some important aspect of their lives, such as work or custody cases. In addition, social desirability can influence the results. In other words, individuals may unintentionally answer questions in a way that makes them “look better” or be viewed in a more favorable light by others.

Technology and Personality Assessment

Is there any way to be 100% sure of the findings of personality assessments? Not yet, but psychologists are developing new measures that take advantage of technology, bypassing self-report as much as possible. For example, scanning technology has been used to identify particular areas of the brain associated with personality expression. Canli and colleagues were interested in teasing apart the relationship between personality and mood states. Using fMRI, they found that activity in the anterior cingulate sometimes was associated with extraversion, possibly identifying an area of the brain involved in extraversion and introversion (Canli, Amin, Haas, Omura, & Constable, 2004). Perhaps future technologies will enable more precise assessment of personality characteristics (Eisenberger, Lieberman, & Satpute, 2005).