Flexible Measures

Flexible Measures

Assignment Content
CHAPTER 2

THE SCIENTIFIC STUDY OF PEOPLE

1. QUESTIONS TO BE ADDRESSED IN THIS CHAPTER

2. THE DATA OF PERSONALITY PSYCHOLOGY

a. LOTS of Data

b. How Do Data from Different Sources Relate to One Another?

c. Fixed Versus Flexible Measures Personality Theory and Assessment

d. Personality and Brain Data

e. Personality Theory and Assessment

3. GOALS OF RESEARCH: RELIABILITY, VALIDITY, ETHICAL BEHAVIOR

a. Reliability

b. Validity

c. The Ethics of Research and Public Policy

4. THREE GENERAL STRATEGIES OF RESEARCH

a. Case Studies

i. Case Studies: An Example

b. Correlational Studies

i. Correlational Research: An Example

c. Experiments

i. Experimental Research: An Example

d. Evaluating Alternative Research Approaches

i. Case Studies and Clinical Research: Strengths and Limitations

e. The Use of Verbal Reports

i. Correlational Research and Questionnaires: Strengths and Limitations

ii. Laboratory, Experimental Research: Strengths and Limitations

f. Summary of Strengths and Limitations

5. PERSONALITY THEORY AND PERSONALITY RESEARCH

6. PERSONALITY ASSESSMENT AND THE CASE OF JIM

a. Autobiographical Sketch of Jim

7. MAJOR CONCEPTS

8. REVIEW

Chapter Focus

Three students in a course on personality work together on a research project. They have been instructed to develop a research method for studying the effects of achievement motivation on academic performance. At their first meeting, they realize that they have drastically differing opinions about how to proceed. Alex is convinced that the best approach is to follow one student over the course of the semester, carefully recording all relevant information (grades, changes in motivation, feelings about courses, etc.) to obtain a complete and in-depth picture of a particular case. Sarah, however, thinks little of Alex’s idea because his conclusions would apply only to that one person. She suggests that the group develop a set of motivation questions and give the questions to as many students as possible. She then would examine the correlation between questionnaire responses and performance in school. Yolanda thinks that neither of these approaches is good enough. She thinks that the best way to understand things scientifically is to run experiments. She suggests an experimental manipulation that causes some people to feel motivated and others to feel unmotivated, followed by a measure of test performance.

The students’ views illustrate the three major methods in personality research: case studies, correlational studies using questionnaires, and laboratory experiments. This chapter introduces you to these three research methods. First, however, we review the different types of information, or data sources, that might go into any study, as well as the general goals that investigators have when they conduct research on personality.

QUESTIONS TO BE ADDRESSED IN THIS CHAPTER

1. What kind of information is it important to obtain when studying personality?

2. What does it mean to say that scientific observations must be “reliable” and “valid”?

3. How should we go about studying people? Should we conduct research in the laboratory or in the natural environment? Through the use of self-reports or reports of others? Through study of many subjects or a single individual?

4. How much difference does it make to study people with one or another type of data? Or through one versus another approach to research? In other words, to what extent will the person “look the same” when studied from different vantage points or perspectives?

Chapter 1 suggested that, at an intuitive level, everyone is a personality theorist. Everybody thinks about people—what makes them “tick”; what affects their psychological development; how, and why, they differ. The personality psycho-logist’s theorizing, however, differs from yours. As you learned, personality scientists must formulate their ideas very explicitly, so that they can be tested by objective scientific evidence.

Here in Chapter 2, we turn to personality research. In so doing, we find a similar theme. Everybody, at an intuitive level, is a personality researcher. We all observe differences among people, as well as consistent patterns of behavior within individuals. These observations constitute the “research evidence” we use to formulate our intuitive personality theories.

However, once again, your intuitive “research” differs from that of the personality scientist. Scientists follow established procedures to maximize the objectivity and accuracy of the information they obtain. They report their research procedures and results in scientific journals, which enables other scientists to replicate their procedures and verify their findings. This chapter introduces you to the research practices of the personality psychologist.

Although this chapter is devoted to research, not theory, you should bear in mind that questions about theory and research are not as separate as our division of chapters might suggest. One might guess that psychologists would first conduct much “theory-free” research and then develop theories to explain their findings. But this is impossible. There is no such thing as “theory-free” research. Research involves the systematic study of relationships among events. Generally, we need a theory to identify the events that are most important to study. We also need a theory to tell us how to study them.

Suppose, for example, that you wanted to test the idea that people who are anxious about dating relationships do not perform as well as they should on exams in college courses because their anxiety interferes with their learning. To test this idea, you would have to begin by measuring people’s level of anxiety. But how? It is impossible to proceed without making some theoretical assumptions. One option would be to ask people directly “Are you anxious about dating?” But this option makes two risky assumptions: (1) that people are aware of their level of anxiety, and thus are capable of reporting it, and (2) that people will tell you, honestly and accurately, about their anxiety if you ask. These assumptions could be wrong, and a personality theory might specify exactly how they are wrong. For example, psychodynamic theories suggest that some people are so anxious that they are not even aware of their anxiety. They repress it. This theory suggests that you need a different research method. Other potential research procedures, such as measuring physiological arousal or brain functioning to index levels of anxiety, similarly rest on theoretical ideas about what anxiety is, what its underlying causes are, and how it is expressed. Thus, theory and research are closely linked. Theory without research can be mere speculation. Research without theory is meaningless fact gathering.

THE DATA OF PERSONALITY PSYCHOLOGY

There is more than one way to get scientific information, or data, about persons. Consider the options. You could ask a person to tell you what she is like. Alternatively, you could observe her in her day-to-day activities to see for yourself. Or, since this would be rather time consuming, you could ask other people who know this person well to report on her personality. A fourth possibility would be one that does not rely on anyone’s subjective observations or judgments but instead looks at objective facts about the person’s life (school records, job performance, etc.).

LOTS OF DATA

Personality psychologists have recognized these options and have defined four categories of data that one might use in research (Block, 1993). They are (1) life record data (L-data), (2) observer data (O-data), (3) test data (T-data), and (4) self-report data (S-data). This yields a handy acronym: LOTS of data. Personality psychologists consider four data types because each one, individually, has unique strengths and limitations (Ozer, 1999).

L-data consist of information that can be obtained from a person’s life history or life record. For example, researchers interested in the relation between personality factors and school performance obtain life record (L) data: students’ grades in school (Caprara, Vecchione, Alessandri, Gerbino, & Barbaranelli, 2011). Researchers interested in the relation between personality and criminality do not have to ask people “Have you committed any crimes?” and rely on the truthfulness of their answers. Instead, they can access L-data: court and police records of arrests and convictions (Huesman, Eron, & Dubow, 2002). For many personality characteristics, however, such objective records are not available, so other data sources must be considered.

O-data consist of information provided by knowledgeable observers such as parents, friends, or teachers. Generally such persons are provided with a questionnaire or other rating form with which they rate the target individual’s personality characteristics. For example, friends might complete a questionnaire in which they rate an individual’s level of friendliness, extraversion, or conscientiousness. Sometimes observers are trained to observe individuals in their daily lives and to make personality ratings based on these observations. As one example, camp counselors have been trained to observe systematically the behavior of children at camp, in order to relate specific forms of behavior (e.g., verbal aggression, physical aggression, compliance) to features of the camp setting or to general personality characteristics (e.g., self-confidence, emotional health, social skills) (Shoda, Mischel, & Wright, 1994; Sroufe, Carlson, & Shulman, 1993). As is clear from these examples, O-data can consist of observations of very specific pieces of behavior or of more general ratings based on observations of behavior. In addition, data on any individual can be obtained from one observer or from multiple observers (e.g., one friend or many friends, one teacher or many teachers). In the latter case, one can check for agreement or reliability among observers.

T-data consist of information obtained from experimental procedures in which researchers measure people’s performance on tasks. In the mid-20th century, personality psychologists developed large numbers of such tasks. For example, they measured participants’ ability to figure out the emotions experienced by people described in a short story; tendency to fidget while sitting in a chair; and their facial expressions while experiencing mild electric shocks (Cattell & Gruen, 1955). Recently, there has been a resurgence of interest in T-data, thanks in part to computer-based technologies that make it much easier than in the past to administer and analyze large numbers of performance-based tests (Ortner & Schmitt, in press). Some other examples of T-data are measures of children’s ability to wait calmly in order to receive a large reward (Mischel, 1990, 1999) or of the speed with which adults answer questions revealing of their personality qualities or social opinions (De Houwer, Teige-Mocigemba, Spruyt, & Moors, 2009). In all such cases, T-data are objective; that is, they do not involve a subjective impression of a person but, instead, an objective record of his or her performance on a task.

Finally, S-data is information that participants report about themselves (the “S” stands for “self”). By far the most common source of S-data is questionnaires. When completing a personality questionnaire, the test-taker is asked to play the role of observer of his or her own personality, making ratings about the self (e.g., “Are you a conscientious person?”). Personality questionnaires can measure a single personality characteristic or may be designed to measure the entire domain of personality. In the latter case, the questionnaire generally contains a large number of test items that tap a number (usually between 2 and 16) of distinct personal qualities (e.g., Tellegen & Waller, 2008). S-data have limitations. People may be unaware of some of their own psychological characteristics or may be motivated to present themselves in a positive manner. Either possibility yields test responses that fail to reveal personal qualities accurately. Nonetheless, their convenience, combined with their documented ability to predict significant psychological outcomes (as you’ll see in the chapters ahead), makes questionnaire-based S-data a very popular data source.

With the widespread use of the Internet, another self-report instrument has been made available to personality psychologists. Self-report questionnaires now are posted on the Internet, with thousands of individuals often responding to them. Rather than being limited to responses from college students, as often is the case in personality research using self-report questionnaires, Internet data include responses from a diverse sample of respondents. A comparison of Internet findings with findings based on the use of self-report questionnaires through more traditional means suggests that the two methods yield comparable results. Thus, this research indicates that the Internet could be used to gain valuable insights into the personality functioning of individuals (Gosling, Vazire, Srivastava, & John, 2004).

The LOTS categories are a useful system for organizing the field’s alternative sources of data. However, when thinking about these categories, you should keep two points in mind. (1) Researchers commonly combine data sources in any given study. For example, researchers searching for patterns in ratings of personality obtain both O-data and S-data. They find that similar patterns emerge with either data source (McCrae & Costa, 1987). Such a finding bolsters confidence in the conclusion that these patterns represent significant features of human personality, rather than artifacts associated with one particular source of data collection. (2) Some data sources do not fit easily into the LOTS organizational scheme. As the field of personality psychology has progressed, new types of measurement have been developed. Additional categories may be necessary to capture the field’s contemporary diversity of methods (Cervone & Caprara, 2001). For example, data about personality and the brain (reviewed below) do not easily fit the LOTS scheme.

HOW DO DATA FROM DIFFERENT SOURCES RELATE TO ONE ANOTHER?

Having introduced four categories of data, a question to ask is whether measures obtained from the different types of data agree with one another (Pervin, 1999). If a person rates herself as high on conscientiousness, will others (e.g., friends, teachers) rate her similarly? If an individual scores high on a questionnaire measuring depression, will ratings given by a professional interviewer lead to a similar score? If an individual rates himself as high on extraversion, will he score high on that trait in a laboratory-designed situation to measure that trait (e.g., participation in a group discussion)?

The seemingly simple question of whether different data sources relate to one another is more complicated than it sounds. Numerous factors influence the degree to which data sources are related. One is the question of which data sources one is talking about. Personality psychologists frequently have found that self-reports (S-data) are often discrepant from scores obtained from laboratory procedures (T-data). Self-report questionnaires tend to involve broad judgments that relate to a wide variety of situations (e.g., “I generally am pretty even tempered”), whereas experimental procedures measure personality characteristics in a very specific context. This difference often is critical, resulting in discrepancies between the two types of data.

Self-reports (S-data) and observer reports (O-data) tend to be related more closely. Personality psychologists commonly find significant levels of agreement when comparing self-ratings to observer ratings (e.g., Funder, Kolar, & Blackman, 1995; McCrae & Costa, 1987). Yet here, too, different types of research procedures can lead to different conclusions (John & Robins, 1994; Kenny, Albright, Malloy, & Kashy, 1994; Pervin, 1999). When the personality characteristic being rated is highly evaluative (e.g., stupid, warmhearted), self-perception biases enter the rating process, lowering agreement between self and observer ratings (John & Robins, 1993, 1994; Robins & John, 1997). Moreover, some personality characteristics are more observable and easier to judge than others (e.g., sociability versus neuroticism), leading to greater agreement between self and observer ratings as well as to greater agreement among ratings obtained from different observers of the same person (Funder, 1995; John & Robins, 1993). Furthermore, some individuals appear to be easier to read or more “judgable” than others (Colvin, 1993). In sum, a variety of factors—including the degree to which a personality characteristic is evaluative and observable, and the degree to which the person being rated is “judgeable”—affect the correspondence between data sources.

In general, the different sources of data about personality should be recognized as having their own advantages and disadvantages. Self-report questionnaires have a clear advantage: People know a lot about themselves, so if a psychologist wants to know people, maybe the best thing to do is to ask them about themselves (Allport, 1961; Kelly, 1955; Lucas & Diener, 2008). Yet, self-report methods have limits. People’s descriptions of themselves on questionnaires can be influenced by irrelevant factors such as the phrasing of test items and the order in which items appear on a test (Schwarz, 1999). People also may lie or may unconsciously distort their questionnaire responses (Paulhus, Fridhandler, & Hayes, 1997), perhaps in an attempt to present themselves in a positive light.

For such reasons, some researchers feel that the best measure of an individual’s personality is questionnaire ratings by others who know the person. Yet here, too, problems may arise; different raters may sometimes rate the same person in quite different ways (Hofstee, 1994; John & Robins, 1994; Kenny et al., 1994). As a result, some psychologists contend that the field should not rely so heavily on questionnaires—whether those questionnaires are self-reports or are reports by other people who are familiar with a given individual. Instead, objective measures of behavior and of biological systems underlying that behavior may be a more reliable source of evidence for building a science of personality (Kagan, 2003). Yet the personality psychologist is often interested in aspects of personal experience that do not have any simple behavioral or biological markers. If one wants to know about people’s conscious perceptions of themselves and their beliefs about the world around them, then we’re back where we started: The best thing to do is to ask them.

FIXED VERSUS FLEXIBLE MEASURES

Another way in which sources of data about personality can differ involves the question of whether measures are fixed or flexible. By “fixed,” we mean procedures in which exactly the same measures (e.g., exactly the same test items) are administered to all the people in a psychological study, and scores for all the people are computed in exactly the same way. Such “fixed” procedures are, by far, the most commonly employed method in personality psychology. If psychologists want to know about people’s characteristics, they generally give large groups of people precisely the same test items and compute scores for everyone in a common manner.

Fixed procedures have clear advantages: They are objective and simple. Yet they have two limitations as well. One is that some of the test items that the psychologist asks may be irrelevant to some of the individuals taking the test. If you have ever taken a personality questionnaire, you may have felt that some of the questions were good ones, tapping into an important feature of your personality, whereas others were not good ones, in that they asked about topics irrelevant to you. A fixed testing procedure does not differentiate between the two types of items; it simply adds up all of your responses and computes for you a total score on a test. The second limitation is that some features of your personality may not be included in a fixed test. You may possess some idiosyncratic psychological quality—an important past experience, a unique skill, a guiding religious or moral value, a long-term goal in life—that is not mentioned in any of the psychologist’s test items.

These limitations can, in principle, be overcome by adopting flexible testing procedures—in other words, procedures that do something other than give all people a common set of questions. Various options are available (Cervone & Shadel, 2003; Cervone, Shadel, & Jencius, 2001; Huprich & Meyer, 2011). For example, one is to administer a fixed set of test items, but to allow them to indicate which items are more or less relevant to them (Markus, 1977). Another is to give people unstructured personality tests, that is, tests in which the items allow people to describe themselves in their own words, rather than forcing them to respond to descriptions worded entirely by the experimenter. A question such as “True or false: I like going to large parties” would be a structured item, whereas the question “What activities do you enjoy on the weekends?” would be unstructured. Unstructured methods have proven to be quite valuable in assessing the self-concept. These methods include asking people to list words or phrases that describe important aspects of their personality (Higgins, King, & Mavin, 1982), or to tell stories that relate their memories of important life experiences that they have had (McAdams, 2011; Woike & Polo, 2001).

Personality psychologists have a technical vocabulary to describe these fixed versus flexible measures. Fixed measures, which are applied in the same manner to all persons, are referred to as nomothetic . The term comes from the Greek for “law,” nomos, and refers here to the search for scientific laws that apply, in a fixed manner, to everyone. Flexible assessment techniques tailored to the particular individual being studied are referred to as idiographic , a term deriving from the Greek idios, referring to personal, private, and distinct characteristics (as in “idiosyncratic”). In general, then, nomothetic techniques describe a population of persons in terms of a fixed set of personality variables, using a fixed set of items to measure them. Idiographic techniques, in contrast, have the primary goal of obtaining a portrait of the potentially unique, idiosyncratic individual. As you will see in later chapters, the personality theories differ in the degree to which they rely on fixed versus flexible (nomothetic versus idiographic) testing procedures.

PERSONALITY AND BRAIN DATA

The four types of data discussed above—the “LOTS” data types—are psychological. That is, these data sources inform researchers about people’s psychological responses: their behavior, thoughts, and emotional reactions.

In addition to the psychology, personality psychologists are interested in biology. They want to identify biological mechanisms that contribute to people’s enduring and distinctive patterns of feeling, thinking, and behaving—that is, to their personality. (Recall our definition of personality from Chapter 1.) The primarily biological mechanisms are found, of course, in the brain. Personality psychologists thus need brain data to complement their psychological “LOTS” data.

Two types of evidence about brain functioning have proven particularly valuable to personality psychology. We’ll describe them briefly here, and you’ll see them again in the chapters ahead.

The first source of brain data capitalizes upon the brain’s electrical properties. Electroencephalography (EEG) is a method for recording electrical activity in the brain. The recordings are made through electrodes placed on the scalp. These electrodes record the electrical activity of the brain’s individual cells, or neurons; the biochemical activity of neurons inside the brain generates electrical activity that is so powerful that it can be detected by electrodes outside the brain, on the scalp. EEG recordings generally are made in laboratories; however, portable, wearable technologies have recently been developed that enable recordings to be made outside of laboratory settings (Casson et al., 2010).

In EEG research, numerous electrodes are placed on different regions of the scalp. Each electrode is most sensitive to brain activity in regions of the brain closest to it. By analyzing activity in multiple electrodes, then, researchers can determine which areas of the brain are most active at any given time. By simultaneously monitoring participants’ (a) psychological state (e.g., experience of different emotions) and (b) EEG activity (specifically, activity in each of the electrodes), researchers can relate psychological activity to brain activity, and thus identify regions of the brain that may underpin specific psychological states and functions.

The second source of evidence about the brain is functional magnetic resonance imaging (fMRI), a method for depicting (or “imaging”) brain activity while a person carries out different tasks (or psychological “functions”). fMRI draws upon the fact that blood blow to different areas of the brain fluctuates as those brain areas become active during task performance. Just as additional blood flows to a muscle in your arm if you use it to lift a weight, additional blood flows to an area of your brain if you use it to, for example, solve a problem, remember a past event, or form a mental image. fMRI technology detects these variations in blood flow and produces a picture of the brain that shows its most highly active regions, and thus “functional” regions—that is, the regions that contributed directly to the task being performed (Ulmer & Jansen, 2010).

In fMRI research, participants are placed in a specialized device called a brain scanner. The scanner contains a powerful magnet that detects variations in blood flow (which are detectable thanks to the magnetic properties of blood cells). While in the scanner, participants see task instructions, pictures, and other stimuli on video screens, and perform tasks in response to these stimuli. The brain scans are taken while participants perform these tasks.

As noted, EEG and fMRI provide information about biological functions, not psychological experiences. However, by combining the biological methods with the psychological LOTS data described above, researchers can link biology to psychology and discover the biological bases of personality processes and structures.

PERSONALITY THEORY AND ASSESSMENT

One of the jobs that a personality psychologist must accomplish is assessment. A personality assessment is any standardized procedure—that is, a procedure with a well-specified set of steps—for learning about an individual’s personality or for measuring differences in personality among people in a population. (A population is any large group of individuals of interest to a given researcher.) Personality assessment procedures yield the basic data that psychologists use to accomplish their main professional goals, such as predicting people’s behavior, conducting experimental research on basic personality processes, and, in clinical applications, understanding psychological problems and formulating therapy strategies.

When selecting a source of data to use in personality assessment, the psychologist has a lot of options: four different sources of psychological data; idiographic versus nomothetic strategies for collecting data through those sources; and different methods for obtaining evidence about the brain, as discussed above. How is one to choose?

Theory commonly guides the choice. Theories of personality dictate targets of assessments, that is, the aspects of personality that are most important to study. The choice of an assessment target may dictate the source of data one pursues. Let’s briefly consider four targets of assessment in personality psychology.

· Average Behavior: Some personality theories target for study people’s typical, average behavior. Average behavioral tendencies are thought to reveal inner personality structure. Assessments, then, are designed to measure what people do on average—their average tendency to be calm (vs. anxious), outgoing (vs. socially withdrawn), honest (vs. deceptive), and so forth (e.g., Van der Linden, Tsaousis, & Petrides, 2012).

· Variability in Behavior: Other theories suggest that assessing average tendencies in behavior is insufficient. One also must explore variations in behavior across social settings. Patterns of variability—for example, warm relationships with one parent and hostile relationships with another; or anxious behavior in some situations and calm, confident behavior in others—are thought to be revealing of personality structure (Mendoza-Denton & Ayduk, 2012).

· Conscious Thought: A third target for assessment is conscious experience, that is, a person’s flow of conscious thoughts, feelings, and emotions. In a study of personality and conscious experience, a researcher might, for example, ask people to describe their beliefs about themselves, their personal goals in life, or their feelings (of excitement or boredom, worry or calm concentration) as they go about the events of their day (Nakamura & Csikszentmihalyi, 2009).

· Unconscious Mental Events: A fourth target for assessment is thoughts and feelings that are not consciousness. Some personality theories highlight unconscious mental events, that is, mental events (e.g., thoughts, motives) of which people are not aware. Researchers whose work is guided by these theories must, then, devise methods for uncovering unconscious mental contents (e.g., McClelland, Koestner, & Weinberger, 1989).

How does a choice of assessment target guide the choice of data to pursue? With just a bit of thinking, you can figure this out for yourself. Consider some questions:

Could you use O-data (observer ratings) or S-data (self-ratings) to assess people’s average behavioral tendencies? Sure, that’s reasonable; people should be able to report, with some accuracy, about their typical behavior and the typical behavior of people they observe.

Could you use O-data to assess the flow of conscious thought? No; if an observer sees you daydreaming, for example, she can’t tell what you’re daydreaming about. To assess your conscious experiences, a researcher would need your own self-reports—S-data.

Could you use self-reports (S-data) to assess unconscious thoughts? No again; people can’t directly report on their unconscious thoughts since, of course, they’re unconscious. To measure unconscious mental content, you need specialized laboratory measures—T-data.

The relations among theory, targets of assessment, and choice of data source will be illustrated again and again in the chapters ahead. For now, note that these relations underscore a theme from Chapter 1: One can’t study personality by first collecting a lot of data and then creating a theory. One first needs a theory to decide what to measure and how to measure it.

GOALS OF RESEARCH: RELIABILITY, VALIDITY, ETHICAL BEHAVIOR

No matter what question one is studying, and no matter what method one chooses, a research project cannot succeed unless its procedures possess two qualities: Measures of personality (1) must be replicable (if the study is run twice it should turn out the same way both times) and (2) must truly measure the theoretical concept of interest in a given study. In the language of research, measures must be (1) reliable and (2) valid.

RELIABILITY

The concept of reliability refers to the extent to which observations can be replicated. The question is whether measures are dependable, or stable. If we give people a personality measure, and then give it to them again a short time later, we expect that the measure will reveal similar personality characteristics at the two time points. If it does not, it is said to be unreliable.

Various factors may affect the reliability of a psychological test. Some involve the psychological state of the people who are being observed; people’s responses may be affected by transient factors such as their mood at the time that they are observed. For example, suppose you take a personality test on two different days and on one, but not the other, you’re in a particularly grouchy mood. Your mood might alter your responses on that day, causing you to get a different test score across the two occasions. Other factors involve the test itself. For example, ambiguities in test items can lower reliability. Carelessness in scoring a test or ambiguous rules for interpreting scores can also lead to a lack of agreement, or lack of reliability, among testers.

Reliability commonly is measured in two different ways, with the different techniques providing answers to different questions about a test (West & Finch, 1997). One method gauges internal consistency: Do the different items on the test correlate with one another, as one would expect if each item is a reflection of a common psychological construct? The second measures test-retest reliability: If people take the test at two different points in time, do they get the same, or highly similar, test scores? The differences between the types of reliability are made plain by a simple example. Suppose one added a few intelligence test items to a test of extraversion. The test-retest reliability of measure would remain high (since people would probably have similar performance on the intelligence test items at different points in time). But the internal consistency of the test would be lowered (since responses on extraversion and intelligence test items probably would not be correlated).

VALIDITY

In addition to being reliable, observations must be valid. Validity is the extent to which observations actually reflect the phenomena of interest in a given study. The concept of validity is best illustrated by an example in which a measure is not valid: One could assess people’s intelligence by asking them trivia questions about the winner’s of TV talent shows. The measure could turn out to be reliable. But it would not be valid because there trivia questions are not indicators of the mental capabilities that we call “intelligence.”

For a test to be useful in the development and testing of personality theory, it must have construct validity: It must be a valid measure of the psychological variable, or construct, that it purports to measure (Cronbach & Meehl, 1955; Ozer, 1999). To establish that a test possesses construct validity, personality psychologists generally try to show that the test relates systematically to some external criterion, that is, to some measure that is independent of (i.e., external to) the test itself. Theoretical considerations guide the choice of an external criterion. For example, if one were to develop a test of the tendency to experience anxiety and wanted to establish its construct validity, one would use theoretical ideas about anxiety to choose external criteria (e.g., physiological indices of anxious arousal) that the test should predict. One generally would establish validity by showing that the test correlates with the external criterion. However, in addition to correlational data, tests of validity might involve comparisons of two groups of people who are theoretically relevant to the test. A group of people who have been diagnosed by clinical psychologists as suffering from an anxiety disorder, for example, should get higher scores on the purported anxiety test than people who have not been so diagnosed; otherwise one obviously would not have a valid test of anxiety.

There are other aspects of validity (Ozer, 1999; West & Finch, 1997). For example, if one is proposing a new personality test, one should be able to demonstrate that the test has discriminant validity: It should be distinct, empirically, from other tests that already exist. If, hypothetically, one proposes a new test of “worrying tendencies” and finds that it correlates extremely highly with existing tests of neuroticism, then the new test is of little value because it lacks discriminant validity.

A relatively new idea about test validity ties the concept of validity to the concept of causality. A test, in this view, is a valid measure of a psychological quality if (a) that quality actually exists and (b) variations in the quality causally influence the outcomes of the measurement process (Borsboom, Mellenbergh, & van Heerden, 2003). Here’s an example. Suppose the quality you want to measure is “skill in solving everyday social problems” (e.g., problems such as figuring out how to have more friends or save more money). A valid measure might be the number of solutions people can generate when presented with everyday problems to solve (Artistico, Orom, Cervone, Krauss, & Houston, 2010). It is valid because it fits both criteria: (1) The attribute exists: All individual people possess some level of skill in solving everyday problems; (2) Variations in the attribute cause variations in the outcome: A lower level of skill (less knowledge of problem-solving strategies and less ability to put that knowledge into practice) causes people to generate fewer solutions. Contrast this example with a hypothetical one: a measure of the influence of ghosts on personality functioning. (The measure might contain questions such as “How many times in the past month has your personality been affected by ghosts? 1–3 times? 4–10 times? >10 times?). No matter what people say in response to the test, and no matter what the correlation between test responses and other outcomes, the test is not a valid measure of the construct, in this new view. Why not? Because the attribute (ghosts and their influence) does not exist. Since it doesn’t exist, it cannot exert a causal influence on test responses. Thus there can be no valid measure of this construct, in a causal account of test validity.

In sum, reliability concerns the questions of whether a test provides a stable, replicable measure, and validity concerns the questions of whether a measure actually taps, and is influenced by, the psychological quality it is supposed to be measuring.

THE ETHICS OF RESEARCH AND PUBLIC POLICY

Research in psychology is laden with ethical concerns. Ethical issues pervade both the conduct of research and the analysis and reporting of research results (Smith, 2003). These concerns are long standing. A half-century ago, in a famed line research, participants in the role of “teachers” were instructed to teach other participants (“learners”) a list of paired associate words and to punish them with an electric shock when they made errors on the word list (Milgram, 1965). Although actual shock was not used, the “teachers” believed it was. Many administered high shock levels despite the learner’s pleas for them to stop. In another study, participants lived in a simulated prison environment in the roles of guards or prisoners (Zimbardo, 1973). “Guards” verbally and physically abused the “prisoners,” who allowed themselves to be treated in a dehumanized way. In both studies, participants experienced such severe levels of stress that one must question whether the gains to science outweighed the costs to the participants.

Such research programs raise fundamental questions about the ethics of research. Do experimenters have the right to deceive research participants? To place them under significant stress? These, in turn, raise a broader question: What ethical principles guide answers to such questions?

The American Psychological Association (APA) has adopted a set of ethical principles (American Psychological Association, 1981). Their essence is that “the psychologist carries out the investigation with respect and concern for the dignity and welfare of the people who participate.” This includes evaluating the ethical acceptability of the research, determining whether subjects in the study will be at risk in any way, and establishing a clear and fair agreement with research participants concerning the obligations and responsibilities of each. Although deception is recognized as necessary in some cases, it must be minimized. Researchers always bear a responsibility to minimize participants’ physical and mental discomfort and harm. In addition to the APA guidelines, similar federal guidelines (that is, within the United States, guidelines formulated by a branch of the U.S. federal government) guide research. All research projects in psychology must be reviewed and approved by an ethics board that evaluates whether the research adheres to these guidelines.

As noted, ethical principles also apply to the reporting of research results. A long-standing concern is “the spreading stain of fraud” (APA Monitor, 1982)—that is, the possibility that the researcher’s reporting of results is not accurate but, instead, has been distorted by his or her personal motives. In the 1970s, statistical analyses indicated that Sir Cyril Burt, a once prominent British psychologist, intentionally misrepresented data when reporting research on the inheritance of intelligence (Kamin, 1974). Early in the 20th century, a researcher was forced to retract from the scientific literature a previously published study because it did not accurately report valid research results (Ruggiero & Marx, 2001). More recently, a psychologist resigned from his job after admitting that data in multiple studies of his were entirely fabricated (New York Times, November 2, 2011).

Fraudulent research reports are rare. Yet, in psychology or any science, fraud is not impossible. Science’s safeguard against fraud is independent replication, that is, replication of results by a researcher other than the one who ran the original study. A large percentage of the results you’ll read about in this book have been replicated independently.

Much more subtle than fraud are personal and social biases that affect how scientific questions are developed and what kinds of data are accepted as evidence (Pervin, 2003). In the study of sex differences, for example, researchers might pose questions in a manner that is gender biased (e.g., asking whether “women are as skillful as men” on a task) or might be more likely to accept the validity of research results that fit their preexisting expectations about men and women. Although scientists strive to remain objective, they—just like anyone else—may sometimes fail to recognize how their personal opinions and expectations affect their judgments and conclusions.

The ethical reporting of research in personality psychology is important not only to advances in science, but to society at large. Personality research is applied in numerous domains: clinical treatments for psychotherapy; educational policies to motivate students; tests to select among applicants for jobs; and so forth. These applications heighten the research psychologist’s responsibility to report research accurately and comprehensively.

THREE GENERAL STRATEGIES OF RESEARCH

All personality scientists hope to obtain research results that are reliable and valid, as you learned above. They differ, however, in the strategies through which they try to achieve that goal. Three overarching research strategies predominate in the field: (1) Case Studies; (2) Correlational Studies; and (3) Experiments. Let’s introduce these three strategies now. You’ll see them again and again in later chapters.

CASE STUDIES

One strategy is to study individual persons in great detail. Many psychologists feel that in-depth analyses of individual cases, or case studies , are the best way to capture the complexities of human personality.

In a case study, a psychologist interacts extensively with the individual who is the target of the study. In these interactions, the psychologist tries to develop an understanding of the psychological structures and processes that are most important to that individual’s personality. Using a term introduced previously, case studies inherently are idiographic methods in that the goal is to obtain a psychological portrait of the particular individual under study.

image1 Tactics of Research: Case studies represent one approach to personality research.

Case studies may be conducted purely for purposes of research. Historically, however, most case studies have been conducted as part of clinical treatment. Clinical psychologists, of course, must gain an understanding of the unique qualities of their clients in order to craft an intervention, so the clinical setting inherently provides case studies of personality. Case studies by clinicians have played an important role in the development of some major theories of personality. In fact, many of the theorists we will discuss in this book were trained as clinical psychologists, counseling psychologists, or psychiatrists. They initially tried to solve the problems of their patients and then used the insights obtained in this clinical setting to develop their theories of personality.

Case Studies: An Example

To illustrate the insights that can be gained by a systematic case study, we will consider work by the Dutch personality psychologist Hubert Hermans (2001). Hermans is interested in the fact that people’s thoughts about themselves—or their self-concept—are generally multifaceted. People think of themselves as having a variety of psychological characteristics. These concepts about the self develop as individuals interact with other people. Since each of us interacts with many different people, different aspects of our self-concept might often be relevant to different situations that feature different individuals. You might see yourself as being serious and articulate when interacting with professors, fun loving and confident when hanging out with friends, and romantic yet anxious when on a date. To understand someone’s personality, then, it might be necessary to study how different aspects of the self come into play as people think about their life from different viewpoints that involve individuals who play different roles in their life. Hermans (2001) refers to these different viewpoints as different “positions” one can take in viewing oneself.

image2 The challenges of social life vary so greatly that we may adapt to them by being “different selves” in different settings.

This view of the self-concept raises a major challenge for most forms of research. Correlational and experimental studies generally provide a small amount of information about each of a large number of persons. But to understand the complexity of self-concept as Hermans describes it requires a large amount of information about a person and the individuals and social circumstances that make up that person’s life. When this level of detail about the individual is required, personality psychologists turn to the technique of case studies.

Hermans (2001) reports a case study that reveals the complexity of personality in our modern day and age, in which people from different cultures come in contact with one another much more frequently than in the past, due to the migration of individuals from one part of the world to another for purposes of education or employment. The case he reports is that of a 45-year-old man from Algeria named Ali. Although Ali grew up in northern Africa, for more than 20 years he had been living in northern Europe; he worked for a Dutch company and married a woman from the Netherlands.

As part of this case study, Hermans employed a systematic research method that can be used in the study of a single individual. The method is one in which an individual is asked to list characteristics that describe his or her own attributes, as well as to list people and situations that are important to him or her. The individual is then asked to indicate the degree to which each personal characteristic is important, or prominent, in each of the situations. Using these ratings, Hermans provides a graphic depiction of the organization of the individual’s beliefs. In the graphs, an inner circle represents personal characte-ristics and an outer circle represents other people and situations.

Figure 2.1 represents these psychological characteristics in the case of Ali. The graph reveals an interesting fact about Ali. He views his life as having distinct components, and he exhibits different personality characteristics in these different life settings. One component of his self-concept involved family members, on both his own side of the family and his wife’s. These people tended to be very accepting of him. When he was with these people, Ali was happy and outgoing, and was willing to make sacrifices for other individuals. Yet, Ali’s view of himself and his social world contained a second component. As is readily understandable for someone who has moved to a new culture that may not always be accepting of immigrants, Ali recognized that some people discriminated against him or held political views with which he disagreed. With these people, he felt vulnerable and disillusioned. Interestingly, he also felt this way with his sister, whom both he and his wife viewed as “the witch of the family” (Hermans, 2001, p. 359). The detailed information provided by this case study, then, provides insight into the textures of this individual’s life that is generally unavailable through other research methods.

image3

Figure 2.1 Self-Concepts: Results from a case study of an Algerian man living in the Netherlands, married to a Dutch woman.

From Hermans (2001).

CORRELATIONAL STUDIES

Personality tests and questionnaires are used where the intensive study of individuals is not possible or desirable and where it is not possible to conduct laboratory experiments. Beyond this, the advantage of personality questionnaires is that a great deal of information can be gathered on many people at one time. Although no one individual is studied as intensively as with the case study approach, the investigator can study many different personality characteristics in relation to many different research participants.

image4 Tactics of Research: Personality questionnaires are used to obtain a great deal of information about many subjects.

The use of personality tests and questionnaires has tended to be associated with an interest in the study of individual differences. Many personality psychologists believe that the critical first step in understanding human nature is to chart the differences among people. Personality questionnaires often are designed to measure these individual differences. For example, personality psychologists might have an interest in using questionnaires to measure individual differences in anxiety, self-consciousness, friendliness, the tendency to take risks, or other psychological qualities.

In addition to measuring these personality variables, the psychologist generally wishes to know how they go together. Are anxious people more friendly than less anxious people? Or less friendly? Do self-conscious people take fewer risks? Are risk-taking people friendlier? Such questions are addressed in correlational research . This term comes from the statistic used to gauge the degree to which two variables go together: the correlation coefficient . A correlation coefficient is a number that reflects the degree to which two measures are linearly related. If people who have higher scores on one variable tend also to have higher scores on the other one, then the variables are said to be positively correlated. (Anxiety and self-consciousness would tend to be correlated in this way.) If people who have higher scores on one variable tend to have lower scores on the other one, then the variables are said to be negatively correlated. (Anxiety and self-confidence might be correlated this way, since people who express low self-confidence are likely to report being relatively more anxious.) Finally, if two variables do not go together in any systematic linear manner, they are said to be uncorrelated. (Anxiety and friendliness may be uncorrelated, since both anxious and nonanxious people may be either friendly or unfriendly.) The correlation coefficient is computed in such a way that a perfect positive correlation—that is, a correlation in which the point falls exactly on a single line—is a correlation of 1.0. A perfect negative correlation is one of –1.0. A correlation of zero indicates that there is no linear relation between two measures.

Note that the term correlational research refers to a research strategy, not merely to a particular statistical measure (the correlation). The strategy is one in which researchers examine the relation among variables in a large population of people, where none of the variables is experimentally manipulated. In some circumstances, researchers may not compute a simple correlation coefficient to examine the relation between two variables; they may, for instance, use more complex statistical procedures that determine whether two variables are related, even after controlling for the influence of some other variables. (For example, one might ask whether intelligence test scores are related to personal income after controlling for other variables, such as the income level of one’s parents.) Even if such alternative approaches to analyzing data are used, one will still have a correlational research strategy if one is looking at the relation among variables without manipulating these variables experimentally.

Correlational Research: An Example

A compelling example of the power of correlational research to answer questions that cannot be answered through any other technique is found in a study relating personality characteristics to longevity (Danner, Snowdon, & Friesen, 2001). The question being asked in this research is whether the tendency to experience positive emotions is related to how long people live. Prior work had established that people’s emotional life can influence their physical well-being. For example, emotions are associated with activation of the autonomic nervous system (ANS); ANS activity, in turn, influences the cardiovascular system (Krantz & Manuck, 1984), which is critical to health. The implication of this prior work is that if one could identify people who differ in their tendencies to experience positive and negative emotions, and could follow these people for a long enough period of time, one might find that people who tended to experience high degrees of positive emotion will live longer. Note that this is a question that can only be answered through correlational research. A case study is not convincing because, even if one does identify a case in which someone experiences a lot of positive emotions and lives for many years, it is impossible to know if the single case is typical of people in general. An experimental study is impossible, both because one cannot easily manipulate people’s general tendency to experience emotional states and because it would be unethical to manipulate a variable that might lower people’s length of life. Correlational research on this topic could be conducted thanks to a project known as the “nun study” (Danner et al., 2001). This is a study of a large number of Catholic nuns living in the United States. The nuns in the study were all born before the year 1917. In 1930, an administrative official of the Catholic Church had asked them to write an autobiography. The researchers, with the permission of the nuns, read these autobiographies and coded them according to the amount of positive emotions expressed in the writing. Some autobiographies contained relatively little positive emotional content (e.g., “I intend to do the best for our order, for the spread of religion and for my personal sanctification”), whereas others indicated that the writer experienced high degrees of positive emotion (“the past year … has been a very happy one. Now I look forward with eager joy”; Danner et al., 2001, p. 806).

image5 Research indicates that individuals who experience a relatively high level of positive emotions tend to live longer.

During the 1990s and the year 2000, approximately 40% of the nuns, who at the time ranged in age from 75 to 95 years, died. The researchers could relate the experience of positive emotions, as indicated in the biographies of 1930, to length of life at the end of the century.

This study revealed a strikingly large relationship between emotional experience and length of life. Nuns who experienced more positive emotions in the 1930s lived longer. The relation between emotional experience and longevity can be represented by counting the number of positive emotion words that were used in the autobiographies and dividing the population into quartiles (i.e., four groupings, each representing approximately one-fourth of the population) ranging from low to high amounts of emotion words (Table 2.1). Of the nuns who had expressed a high amount of positive emotions, only about one-fifth died during the observation period. Of the nuns who expressed low amounts of positive emotion, more than half died! This is true even though the high and low groups were of the same age at the beginning of the observation period.

EXPERIMENTS

One of the great achievements of science is not a research finding but a research method: the controlled experiment. The key feature of a controlled experiment is that participants are assigned at random to an experimental condition. The overall experiment contains a number of different conditions that manipulate one or more variables of interest. If people in one condition respond differently than people in another, then one can conclude that the variable that was manipulated causally influenced their responses. This conclusion is valid precisely because people are assigned to conditions randomly. Random assignment assures that there is no systematic relationship between the experimental conditions and people’s preexperimental psychological tendencies. If people in different conditions act differently after the experimental manipulation, despite being the same before it occurred, then the manipulation was the cause of the differences in response. This research strategy, in which variables are manipulated through the random assignment of persons to different conditions, is the hallmark of experimental research .

TABLE 2.1 Relation between Expression of Positive Emotions in Writing as Measured Early in Life and Longevity

Source: Danner, D. D., Snowdon, D. A., & Friesen, W. V. (2001). Positive emotions in early life and longevity: Findings from the nun study. Journal of Personality & Social Psychology, 80, 804–813.

Positive Emotion Words

Age

Died (%)

Quartile I (low)

79.9

55

Quartile II

81.1

59

Quartile III

79.7

33

Quartile IV (high)

79.0

21

CURRENT APPLICATIONS PERSONALITY AND HEALTH

As is evident from the “nun study” reviewed in the text, a major area of application for contemporary personality psychology is that of health. Investigators try to discover individual differences in personality qualities that are systematically related to health outcomes.

A particularly informative example of this research trend comes from recent work by a research team from Finland and the United States (Räikkönon, Matthews, & Salomon, 2003). The health outcome of interest to these researchers was cardiovascular disease. As they mentioned, the biological factors that put people at risk for cardiovascular problems are already well known. A cluster of factors including obesity, high blood pressure, abnormal levels of lipids (blood fats) in the bloodstream, and insulin resistance (a reduced sensitivity to the action of insulin) puts people at risk for heart problems. Also, it is known that the presence of this cluster of health problems—referred to as “metabolic syndrome”—tends to persist from childhood to adulthood; people who suffer from obesity and insulin resistance as children are likely to suffer from these same problems when they are adults.

It is important, then, to determine the causes of metabolic syndrome. The question the researchers asked is whether personality factors in childhood might predict the development of these biological risk factors.

The personality factor that they chose to study was hostility. This decision was based on prior research. Earlier work had demonstrated a relation, among adults, between cardiovascular problems and tendencies to react to life events with hostility and anger. The authors thus predicted that individual differences in hostility in children would predict the development of aspects of metabolic syndrome.

Note that this is a difficult prediction to test. The idea is not merely that hostility and cardiovascular risk factors will go together or be correlated. The specific hypothesis is that hostility will predict the development of risk factors. Children who experience high amounts of hostility at one point in time are predicted to experience relatively higher levels of risk factors at a later point in time. Testing this idea requires a longitudinal research design, that is, a research project in which the relevant variables are assessed at different time points.

The authors executed such a research project. They studied a large group of African-American and European-American children and adolescents. Assessments were conducted twice, at time points separated by an average of more than three years. At both time points, the researchers examined children with high versus low amounts of the cardiovascular risk factors and asked whether these children differed in their levels of hostility.

At time 1 (i.e., the first assessment session), some children did, and others did not, have the cardiovascular risk factors. The children who did not have those factors at time 1 were of particular interest; the researchers, were specifically interested in whether these children would develop the biological risk factors by time 2 and whether the personality factor of hostility would predict who did, versus did not, develop the biological risks. Would children who were more hostile at time 1 develop the health problems that put people at risk for heart disease by time 2?

The researchers found that, as they had expected, hostility predicted the develop-ment of cardiovascular risk factors. Figure 2.2 displays the results for two factors: obesity (measured by body mass index) and insulin resistance. The vertical axis plots levels of hostility, which were assessed by means of an interview; a trained interviewer asked the research participants a series of questions designed to reveal individual differences in their potential to react to situations with a hostile, competitive style of response. Children who developed the two features of the metabolic syndrome by time 2 were found to have differed in hostility at time 1. More hostile children, then, were more likely to develop the cardiovascular risk factors.

image6

Figure 2.2 The figure relates individual differences in hostility to the presence of biological factors that are known to put people at risk for cardiovascular problems. People with higher levels of two risk factors, involving body mass (left) and insulin resistance (right), were found to exhibit higher levels of hostility.

From Räikkönon, Matthews, & Salomon (2003).

Further research is required to determine exactly what explains the link of hostility to health problems. As the authors explain, one possibility is that the development and maturation of biological systems (e.g., growth hormones) is responsible for both hostility and health problems. However, another possibility is that more hostile children are more likely to engage in behaviors that, in turn, create health risks. Hostility may be related to unhealthy lifestyles (smoking, alcohol use, reduced physical activity), and these lifestyles may contribute to the development of health problems. This latter possibility is particularly interesting because it raises the possibility that psychological interventions might have long-term health benefits. Interventions that teach children to control their tendencies to react to the world in a hostile manner may promote better lifestyles and superior health.

Source: Räikkönen, Matthews, & Salomon (2003).

Experimental Research: An Example

A powerful example of experimental research comes from the work of Claude Steele (1997) and colleagues, who have investigated a phenomenon known as “stereotype threat.” Work on stereotype threat explores circumstances in which people are trying to perform well in front of others (e.g., they are taking an exam, and other people, such as the course instructor, will know how well they have performed). In such situations, there sometimes exist negative stereotypes concerning the performance of particular social groups. For example, according to some stereotypes, women may not be as good at math as men, or people of different ethnic backgrounds might be thought to be more or less intelligent. If an individual is a member of a group for which there is a stereotype, and if the individual thinks of the stereotype, then a psychological threat arises. There is a threat in the individual’s mind that he or she might confirm the stereotype. In many circumstances, this stereotype threat may interfere with one’s performance. For example, if you are taking a difficult exam and become distracted by thoughts that you might confirm a stereotype associated with a group of which you are a member, then this distraction might, like any distraction, cause you to perform less well.

image7 One technique for learning about personality is laboratory research. Participants take part in activities in controlled laboratory settings that are designed to identify the ways that specific personality processes contribute to emotion, thinking processes, and performance.

In principle, one could study stereotype threat processes through case studies or correlational studies. However, as we have noted, these approaches would not provide convincing evidence that stereotype threat causally influences performance. To explore this potential causal influence, Steele and colleagues have studied stereotype threat experimentally (Steele, 1997). For example, they have examined the performance of African-American and European-American college students on verbal test items of the sort that might be included on an intelligence test; a negative stereotype about intelligence is one of various stereotypes about African-Americans that persist in U.S. culture. The experiment featured two conditions. In one, all participants first completed a demographic questionnaire in which they were asked to indicate their race. In the other, the demographic questionnaire was omitted. Black and white students were assigned at random to one or the other condition. The results of the study revealed that completing the demographic questionnaire lowered the subsequent test performance of black students (Figure 2.3)—stereotype threat processes caused them to perform less well than whites. Although we review this study for the purpose of illustrating the experimental method, one, of course, should also note its social implications. By asking about racial background on demographic questionnaires, one may inadvertently produce differences in intelligence test scores. Thus, if a group of black students were to obtain lower intelligence test scores than white students, this would not necessarily mean that they possess less intelligence; instead, they could be suffering from stereotype-threat processes that cause the test scores to underestimate their actual intellectual capabilities.

image8

Figure 2.3 Mean performance on a difficult verbal test, by black and white research participants, in each of two experi-mental conditions. The condition varied in whether partici-pants were (Race prime condition) or were not (No race prime condition) asked to indicate their race prior to taking the test.

From Steele, 1997.

image9 Research indicates that if there exists a negative social stereotype about a group, then individual members of that group may perform less well on a test because of stereotype threat processes that interfere with their performance. This can occur even when the individuals are of high intelligence and ability.

Stereotype-threat processes can occur in other settings and with members of other groups. For example, women may be subject to negative stereotypes with regard to performance in mathematics. The threat of confirming these stereotypes may contribute to male-female differences in mathematics test performance. Consistent with this idea, gender differences in which men outperform women in mathematics have been shown to be eliminated when stereotype threat is reduced (Spencer, Steele, & Quinn, 1999). Experimental research on stereotype threat thus illuminates a general psychological process that contributes to important life outcomes.

EVALUATING ALTERNATIVE RESEARCH APPROACHES

Having now reviewed the three major research strategies, we are in a position to evaluate them in detail. As we already have noted, each has strengths and limitations (Table 2.2).

TABLE 2.2 Summary of Potential Strengths and Limitations of Alternative Research Methods

Potential Strengths

Potential Limitations

CASE STUDIES AND CLINICAL RESEARCH

1. Avoid the artificiality of laboratory

1. Lead to unsystematic observation

2. Study the full complexity of person–environment relationships

2. Encourage subjective interpretation of data

3. Lead to in-depth study of individuals

3. Do not establish causal relationships

QUESTIONNAIRES AND CORRELATION RESEARCH

1. Study a wide range of variables

1. Establish relationships that are associational rather than causal

2. Study relationships among many variables

2. Problems of reliability and validity of self-report questionnaires

3. Large samples easily obtained

3. Individuals not studied in depth

LABORATORY STUDIES AND EXPERIMENTAL RESEARCH

1. Manipulate specific variables

1. Exclude phenomena that cannot be studied in the laboratory

2. Record data objectively

2. Create an artificial setting that limits the generality of findings

3. Establish cause–effect relationships

3. Foster demand characteristics and experimenter expectancy effects

Case Studies and Clinical Research: Strengths and Limitations

A major advantage of case studies, particularly as they are conducted in clinical settings, is that they overcome the potential superficiality and artificiality of correlational and experimental methods. In a case study, the investigator learns about deeply important aspects of an individual’s life, which may not occur in a brief experiment or a survey questionnaire. Clinicians conducting case studies directly observe how the client thinks and feels about events. One examines the behavior of interest directly and does not have to extrapolate from a somewhat artificial setting to the real world.

A further advantage is that clinical research may be the only feasible way of studying some phenomena. When one needs to study the full complexity of personality processes, individual environment relationships, and the within-person organization of personality, in-depth case studies may be the only option.

In-depth study of a few individuals has two main features that stand in contrast with research on groups (Pervin, 1983). First, relationships established for a group as a whole may not reflect the way any individual behaves or the way some subgroups of individuals behave. An average learning curve, for example, may not reflect the way any one individual learns. Second, by considering only group data, one may miss some valuable insights into processes going on in particular individuals. Some time ago, Henry Murray argued for the use of individual as well as group studies as follows: “In lay words, the subjects who gave the majority response may have done so for different reasons. Furthermore, a statistical answer leaves unexplained the uncommon (exhibited-by-the-minority) response. One can only ignore it as an unhappy exception to the rule. Averages obliterate the ‘individual characters of individual organisms’ and so fail to reveal the complex interaction of forces which determine each concrete event” (1938, p. viii).

Regarding limitations of the case study method, two significant drawbacks can be noted: (1) findings from one case study may not generalize to other people and (2) the case study method cannot demonstrate causality, that is, that one psychological process causally influences another. In personality science, as in any science, researchers hope to identify the causes of the phenomena they study. They wish not only to describe a person, but to determine how and why different elements of personality affect one another. A case study may provide a wonderful description, but it generally cannot provide a definite causal explanation. For example, imagine a clinical case study that describes changes in an individual’s psychological well-being that occur over the course of a year-long clinical treatment. The case study may describe the changes accurately, but it cannot demonstrate that treatment caused the changes being described. Life events other than clinical treatment may have had causal influence.

There is a third limitation: Case studies often rely on the subjective impressions of researchers. Unlike the correlational and experimental strategies, which commonly employ objective measurement procedures, case studies commonly rest on impressionistic reports, such as a therapist’s subjective impressions of his or her client. Such reports may reflect not only the psychological qualities of the person being studied but the qualities—the beliefs, expectations, and biases—of the psychologist who prepares the report. There is no guarantee that a different researcher examining the same case would come to the same conclusions. This subjective element can lower the reliability and validity of case-study evidence.

The Use of Verbal Reports

Clinical research in personality need not involve the use of verbal reports by subjects, though clearly it often does. In making use of verbal reports, we are confronted with special problems associated with such data. Treating what people say as accurate reflections of what has actually occurred or is actually going on has come under attack from two very different groups. First, psychoanalysts and dynamically oriented psychologists (Chapters 3 and 4) argue that people often distort things for unconscious reasons: “Children perceive inaccurately, are very little conscious of their inner states and retain fallacious recollections of occurrences. Many adults are hardly better” (Murray, 1938, p. 15). Second, many experimental psychologists argue that people do not have access to their internal processes and respond to interviewer questions in terms of some inferences they make about what must have been going on rather than accurately reporting what actually occurred (Nisbett & Wilson, 1977; Wilson, Hull, & Johnson, 1981). For example, despite experimenter evidence that subjects make decisions in accord with certain experimental manipulations, the subjects themselves may report having behaved in a particular way for very different reasons. Or, to take another example, when consumers are asked about why they purchased a product in a supermarket, they may give a reason that is very different from what can experimentally be demonstrated to have been the case. In a sense, people give subjective reasons for behaving as they do but may not give the actual causes. In sum, the argument is that whether for defensive reasons or because of “normal” problems people have in keeping track of their internal processes, verbal self-reports are questionable sources of reliable and valid data (West & Finch, 1997; Wilson, 1994).

Other psychologists argue that verbal reports should be accepted for what they are—data (Ericsson & Simon, 1993). Essentially, the argument states that there is no intrinsic reason to treat verbal reports as any less useful data than an overt motor response, such as pressing a lever. Indeed, it is possible to analyze the verbal responses of people in as objective, systematic, and quantitative a fashion as their other behavioral responses. If verbal responses are not automatically discounted, then the question becomes, Which kinds of verbal responses are most useful and trustworthy? Here the argument is made that subjects can only report about things they are presently attending to or have already handled. If the experimenter asks the subject to remember or explain things that were never attended to in the first place, the subject will either make an inference or state a hypothesis about what occurred (White, 1980). Thus, if you later ask persons why they purchased one product over another in the supermarket when they were not attending to this decision at the time, they will give you an inference or a hypothesis rather than an account of what occurred.

Those who argue in favor of the use of verbal reports suggest that when they are elicited with care and the circumstances involved are appreciated, they can be a useful source of information. Although the term introspection (i.e., verbal descriptions of a process going on inside a person) was discredited long ago by experimental psychologists, there is now increased interest in the potential use of such data. In accepting the potential use of verbal reports, we may expand the universe of potential data for rich and meaningful observation. At the same time, we must keep in mind the goals and requirements of reliability and validity. Thus, we must insist on evidence that the same observations and interpretations can be made by other investigators and that the data do reflect the concepts they are presumed to measure. In appreciating the merits and vast potential of verbal reports, we must also be aware of the potential for misuse and naive interpretation. In sum, verbal reports as data should receive the same scrutiny as other research observations.

Correlational Research and Questionnaires: Strengths and Limitations

A main advantage of correlational studies using questionnaires is sample size. It often is possible to study large numbers of people. By conducting research through the Internet, psychologists can obtain extremely large and diverse samples of participants (Fraley, 2007).

Another advantage of the correlational approach concerns reliability. Many questionnaires provide extremely reliable indices of the psychological constructs they are designed to measure. This is important because tests must be reliable in order to detect important features of personality that might be overlooked otherwise. For example, researchers find that individual differences in personality traits are highly stable over time; people who differ in extraversion or conscientiousness in young adulthood will probably differ in middle and later adulthood as well (e.g., Costa & McCrae, 2002). One could not detect this fact unless the measures of the personality traits were highly reliable.

Correlational studies have been enormously popular among personality psychologists. Yet it is important to be aware of three limitations of this research strategy. The first limitation is one that differentiates correlational studies from case studies. Case studies provide richly detailed information about an individual. In contrast, correlational studies provide relatively superficial information about individual persons. A correlational study will provide information about an individual’s scores on the various personality tests that happen to have been used in the research. But if there are some other variables that are important to an individual person, a correlational study generally will not reveal them.

The second limitation is one that case studies and correlational studies share. As in a case study, in a correlational study it is difficult to draw firm conclusions about causality. The fact that two variables are correlated does not mean that one variable necessarily caused the other. A “third variable” could have influenced both of the variables in one’s study and caused those variables to be correlated. For example, in the nun study, it is possible that some psychological, biological, or environmental factor that was not measured in the study caused some nuns to experience fewer positive emotions and to live less long. As a hypothetical example, if one conducted a study akin to the nun study with college students, one might find that positive emotionality would predict longevity. But that would not necessarily mean that the tendency to experience positive emotions during college caused people to live longer. For example, levels of academic success could function as a third variable. Students who are doing extremely well in college might experience more positive emotions as a result of their academic success. They also might obtain more lucrative jobs after graduation, again as a result of their academic success. Their high-paying jobs might enable them to pay for superior health care, which in turn could lengthen their life whether or not they continue to experience frequent position emotions. In this hypothetical example, emotions and length of life would be correlated, but not because of any direct causal connection between the two.

A third limitation concerns the widespread reliance on self-report questionnaires. When people are describing themselves on a questionnaire, they may be biased to answer items in a way that has nothing to do with the exact content of the items or the psychological construct that the psychologist is trying to assess. These biases are called response styles . Two illustrative response-style problems can be considered. The first is called acquiescence. It involves the tendency to agree consistently (or disagree consistently) with items regardless of their content. For example, a test-taker may prefer to say “Yes” or “I agree” when asked questions, rather than saying “No” or “I disagree.” The second response style is called social desirability. Instead of responding to the intended psychological meaning of a test item, a subject may respond to the fact that different types of responses are more or less desirable. If, hypothetically, a test item asks “Have you ever stolen anything from a store?,” the answer “No” is clearly a more socially desirable response than “Yes.” If people are biased to answer questions in a socially desirable manner, then their test scores may not accurately reflect their true psychological characteristics.

A research report that highlights the problem of distortion of questionnaire responses, while also emphasizing the potential value of clinical judgment, is that of Shedler, Mayman, and Manis (1993). In this research conducted by psychologists with a psychoanalytic orientation who were skeptical of accepting self-report data at face value, individuals who “looked good” on mental health questionnaire scales were evaluated by a psychodynamically oriented clinician. On the basis of his clinical judgments, two subgroups were distinguished: one defined as being genuinely psychologically healthy in agreement with the questionnaire scales and a second defined as consisting of individuals who were psychologically distressed but who maintained an illusion of mental health through defensive denial of their difficulties. Individuals in the two groups were found to differ significantly in their responses to stress. Subjects in the illusory mental health group were found to show much higher levels of coronary reactivity to stress than subjects in the genuinely healthy group. Indeed, the former subjects were found to show even greater levels of coronary reactivity to stress than subjects who reported their distress on the mental health questionnaire scales. The differences in reactivity to stress between the genuinely healthy subjects and the “illusory” healthy subjects were considered not only to be statistically significant but medically significant as well. Thus, it was concluded that “for some people, mental health scales appear to be legitimate measures of mental health. For other people, these scales appear to measure defensive denial. There seems to be no way to know from the test score alone what is being measured in any given respondent” (Shedler et al., 1993, p. 1128).

Those who defend the use of questionnaires note that such problems often can be eliminated through careful test construction and interpretation. Psychologists can reduce or eliminate the effects of acquiescence by varying the wording of items on a test so that consistent “yes” responses do not give one a higher overall test score. They can employ questionnaires that are specifically designed to measure the degree to which a given person tends to endorse socially desirable responses. Comprehensive personality questionnaires commonly include test items or scales to measure whether subjects are faking or trying to present themselves in a particularly favorable or socially desirable way. Including such scales in a research project, however, often is inconvenient or costly, and thus, such scales often are lacking in particular studies.

Laboratory, Experimental Research: Strengths and Limitations

In many ways, our ideal image of scientific investigation is laboratory research. Ask people for their description of a scientist, and they are likely to conjure up an image of someone in a sterile lab. As we have already seen, this image is too limited; personality psychologists employ a range of scientific methods, and laboratory research is but one of them. Yet it is an important one. The experimental approach, as we have noted, has the unique ability to manipulate variables of interest and thereby to establish cause–effect relationships. In the experiment that is properly designed and carried out, every step is carefully planned to limit effects to the variables of interest. Few variables are studied, so that the problem of disentangling complex relationships does not exist. Systematic relationships between changes in some variables and consequences for other variables are established so that the experimenter can say “If X, then Y.” Full details of the experimental procedure are reported so that the results can be replicated by investigators in other laboratories.

Psychologists who are critical of laboratory research suggest that too often such research is artificial and has limited relevance to other contexts. The suggestion is that what works in the laboratory may not work elsewhere. Furthermore, although relationships between isolated variables may be established, such relationships may not hold when the complexity of actual human beha-vior is considered. Also, since laboratory research tends to involve relatively brief exposures to stimuli, such research may miss important processes that occur over time. As you read about personality research in the subsequent chapters of this book, a question to ask yourself is how successful the different theories are in establishing experimental findings that generalize to real-world situations.

As a human enterprise, experimental research with humans lends itself to influences that are part of everyday interpersonal behavior. The investigation of such influences might be called the social psychology of research. Let us consider two important illustrations. First, some factors influencing the behavior of human subjects may not be part of the experimental design. Among such factors may be cues implicit in the experimental setting that suggest to the subject that the experimenter has a certain hypothesis and, “in the interest of science,” the subject behaves in a way that will confirm it. Such effects are known as demand characteristics and suggest that the psychological experiment is a form of social interaction in which subjects give purpose and meaning to things (Orne, 1962; Weber & Cook, 1972). The purpose and meaning given to the research may vary from subject to subject in ways that are not part of the experimental design and thereby serve to reduce both reliability and validity.

Complementing these sources of error or bias in the subject are unintended sources of influence or error in the experimenter. Without realizing it, experimenters may either make errors in recording and analyzing data or emit cues to the subjects and thus influence their behavior in a particular way. Such unintended experimenter expectancy effects may lead subjects to behave in accordance with the hypothesis (Rosenthal, 1994; Rosenthal & Rubin, 1978). For example, consider the classic case of Clever Hans (Pfungst, 1911). Hans was a horse that by tapping his foot could add, subtract, multiply, and divide. A mathematical problem would be presented to the horse and, incredibly, he was able to come up with the answer. In attempting to discover the secret of Hans’s talents, a variety of situational factors were manipulated. If Hans could not see the questioner or if the questioner did not know the answer, Hans was unable to provide the correct answer. On the other hand, if the questioner knew the answer and was visible, Hans could tap out the answer with his foot. Apparently the questioner unknowingly signaled Hans when to start and stop tapping his hoof: The tapping would start when the questioner inclined his head forward, increase in speed when the questioner bent forward more, and stop when the questioner straightened up. As can be seen, experimenter expectancy effects can be quite subtle and neither the researcher nor subject may be aware of their existence.

It should be noted that demand characteristics and expectancy effects can occur as sources of error in all three forms of research. However, they have been considered and studied most often in relation to experimental research. In addition, as noted, experimental research often is seen as most closely approximating the scientific ideal. Therefore, such sources of error are all the more noteworthy in relation to this form of research.

Many of the criticisms of experimental research have been attacked by experimental psychologists. In defending laboratory experiments, the following statements are made: (1) Such research is the proper basis for testing causal hypotheses. The generality of the established relationship is then a subject for further investigation. (2) Some phenomena would never be discovered outside of the laboratory. (3) Some phenomena can be studied in the laboratory that would be difficult to study elsewhere (e.g., subjects are given permission to be aggressive in contrast with the often quite strong restraints in natural social settings). (4) There is little empirical support for the contention that subjects typically try to confirm the experimenter’s hypothesis or for the significance of experimental artifacts more generally. Indeed, many subjects are more negativistic than conforming (Berkowitz & Donnerstein, 1982).

Even if one accepts these four points, there remains one criticism of laboratory research that is difficult, if not impossible, to overcome. It is that some phenomena simply cannot be produced in the laboratory. A personality theory may make predictions about people’s emotional reactions to extreme levels of stress or their thoughts about highly personal matters. For such questions, laboratory methods may not work. It would be unethical to create extremely high levels of stress in the lab. In a brief laboratory encounter, people are unlikely to reveal any thoughts about matters that are highly personal. The personality scientist sometimes is not afforded the luxury of the simple laboratory study.

SUMMARY OF STRENGTHS AND LIMITATIONS

In assessing these alternative approaches to research we must recognize that we are considering potential, rather than necessary, strengths and limitations (Table 2.2). In fact, findings from one approach generally coincide with those from another approach (Anderson, Lindsay, & Bushman, 1999). What it comes down to is that each research effort must be evaluated on its own merits and for its own potential in advancing understanding rather than on some preconceived basis. Alternative research procedures can be used in conjunction with one another in any research enterprise. In addition, data from alternative research procedures can be integrated in the pursuit of a more comprehensive theory.

PERSONALITY THEORY AND PERSONALITY RESEARCH

In Chapter 1, we considered the nature of personality theory: psychologists’ efforts to systematize what is known about personality and to point research in directions that yield new knowledge. In this chapter, we have considered the nature of personality research: psychologists’ efforts to bring objective scientific evidence to bear on their theories. We reviewed the kinds of data obtained by personality psychologists, and then the strengths and limits of three traditional types of personality research (case studies, correlational research, and laboratory experiments).

As we already have noted, personality theory and personality research are not two separate, unrelated enterprises; they are inherently intertwined. Theory and research are related for two reasons, one of which we already have noted: Theoretical conceptions suggest avenues for exploration and specify the types of data that qualify as “evidence” about personality. Personality researchers are interested in a person’s physiological reactions and are uninterested in their astrological signs because personality theories contain ideas that relate physiology to psychological functioning, while leaving no room for the influence of astrological forces.

Theory and research tend to be related in another way. Theorists have preferences and biases concerning how research should be conducted. The father of American behaviorism, John B. Watson, emphasized the use of animals in research in part because of his discomfort in working with humans. Sigmund Freud, founder of psychoanalytic theory, was a therapist who did not believe that important psychoanalytic phenomena could be studied in any manner other than in therapy. Hans Eysenck and Raymond Cattell, two trait theorists of historic importance, were trained, early in their careers, in sophisticated statistical methods involving correlation, and these methods fundamentally shaped their theoretical ideas. Historically, personality researchers have tended to fall on one or the other side of three issues associated with the three approaches to research: (1) “making things happen” in research (experimental) versus “studying what has occurred” (correlational), (2) all persons (experimental) versus the single individual (clinical), and (3) one aspect or few aspects of the person versus the total individual. In other words, there are preferences or biases toward clinical, experimental, and correlational research. Despite the objectivity of science, research is a human enterprise and such preferences are part of research as a human enterprise. All researchers attempt to be as objective as possible in the conduct of their research, and generally they give “objective” reasons for following a particular approach to research. That is, the particular strengths of the research approach followed are emphasized relative to the strengths and limitations of alternative approaches. Beyond this, however, a personal element enters. Just as psychologists feel more comfortable with one or another kind of data, they feel more comfortable with one or another approach to research.

Further, different theories of personality are linked with different research strategies and thereby with different kinds of data. In other words, the links among theory, data, and research are such that the observations associated with one theory of personality often are of a fundamentally different type than those associated with another theory. The phenomena of interest to one theory of personality are not as easily studied by the research procedures useful in the study of phenomena emphasized by another theory of personality. One personality theory leads us to obtain one kind of data and follow one approach to research, whereas another theory leads us to collect different kinds of data and follow another approach to research. It is not that one or another is better but rather that they are different, and these differences must be appreciated in considering each approach to theory and research. This has been true historically and remains true in the current scientific discipline (Cervone, 1991). Since the remaining chapters in this text are organized around the major theoretical approaches to personality, it is important to keep such linkages and differences in mind in comparing one theory with another.

PERSONALITY ASSESSMENT AND THE CASE OF JIM

As we have seen, personality research involves the effort to measure individuals on a personality characteristic assumed to be of theoretical importance. The term assessment generally is used to refer to efforts to measure personality aspects of individuals in order to make an applied or practical decision: Will this person be a good candidate for this job? Will this person profit from one or another kind of treatment? Is this person a good candidate for this training program? In addition, the term assessment often is used to refer to the effort to arrive at a comprehensive understanding of individuals by obtaining a wide variety of information about them. In this sense, assessment of a person involves administering a variety of personality tests or measures in the pursuit of a comprehensive understanding of his or her personality. As noted, such an effort also provides for a comparison of results from different sources of information. This book assumes that each technique of assessment gives a glimpse of human behavior and that no one test gives, or can hope to give, a picture of the total personality of an individual. People are complex, and our efforts to assess personality must reflect this complexity. In the chapters that follow, we will consider a number of theories of personality and approaches to personality assessment. In addition, we will consider the assessment of an individual, Jim, from the standpoint of each theory and approach to assessment. Through this approach we will be able to see the relation between theory and assessment, and also to consider the extent to which different approaches result in similar pictures of the person.

Before we describe Jim, here are some details concerning the assessment project. Jim was a college student when, in the late 1960s, he volunteered to serve as a subject for a project involving the intensive study of college students. He participated in the project mainly because of his interest in psychology but also because he hoped to gain a better understanding of himself. At the time, various tests were administered to him. These tests represented a sampling of the tests then available. Obviously, theories of personality and associated tests that had not been developed at the time could not be administered. However, Jim agreed to report on his life experiences and to take some additional tests 5, 20, and 25 years later. At those times, an effort was made to administer tests developed in association with emerging theories of personality.

Thus, we do not have the opportunity to consider all the tests at the same point in time. However, we are able to consider the personality of an individual over an extended period of time and, thereby, examine how the theories—and the tests—relate to what occurred earlier in life and what followed later. Let us begin with a brief sketch derived from Jim’s autobiography and follow him throughout the text as we consider the various approaches to personality.

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