Chapter 1: Introduction to Personality
Part 2: Methods of Studying Personality
In all types of research, we need to consider two closely related concepts: hypothesis vs. theory. A hypothesis can loosely be defined as an educated guess about some relationship or circumstance that we have observed, and the purpose of the hypothesis is to explain what we have experienced and to provide a starting point for further research. When a set of observations seem to come together, especially as the result of testing our hypotheses, we might then propose a theory to bring those observations together. However, a theory is not necessarily our endpoint, since the theory itself may generate new hypotheses and more research. In this way, all scientific endeavors continue to develop, expand, clarify, change, whatever the case may be, over time. As a result, we have many different personality theories, since different theorists have viewed the human condition differently, and they have also used different techniques to study personality.
A variety of methods have been used to study personality. Much of the early research was based on clinical observations, which were not done according to strict experimental methods. Today, ethical restrictions on the types of research we can conduct with people limit our ability to re-evaluate many of those classic studies. So we are left with a field that is rich in theory, but somewhat poor in the validation of those theories. Of course some personality theorists have approached personality in a more scientific manner, or at least they have tried, but that has limited the questions they have been able to ask. Since a detailed analysis of experimental psychology and research design is beyond the scope of this book, we will only cover this topic briefly (though it may come up again within individual chapters).
Many of the best-known personality theorists relied on case studies to develop their theories. Indeed, it was after seeing a number of patients with seemingly impossible neurological complaints that Freud began to seek an explanation of psychological disorders. Basically, the case study approach relies on a detailed analysis of interesting and unique individuals. Because these individuals are unique, the primary criticism of the case study approach is that its results may not generalize to other people. Of greater concern is the possibility that early theorists chose to report only those cases that seemed to support their theories, or perhaps they only recognized those elements of a patient’s personality that fit their theory? Another problem, as mentioned above, is that two different theorists might view the same cases in very different ways. For example, since Carl Rogers worked initially with children, he found it difficult to accept Freud’s suggestions that even children were motivated primarily by sexual and aggressive urges. Consequently, Rogers sought a more positive view of personality development, which led to the establishment of the humanistic perspective. Thus, the case study approach can lead to very different conclusions depending on one’s own perspective while conducting research. In other words, it can easily be more subjective than objective, and psychologists who focus on our field as a scientific discipline always strive for more objective research.
When conducting correlational research, psychologists examine the relationships that exist between variables, but they do not control those variables. The measure that is typically used is the correlation coefficient, which can range from –1.0 to 0.0 to +1.0. A value close to zero suggests that there is no relationship between the variables, whereas a value closer to –1.0 or +1.0 suggests a strong relationship, with the direction of the relationship determining whether the value is positive or negative. It is important to remember that the strength of the correlation is determined by how far the correlation coefficient is from zero, not whether it is positive or negative. For example, we would most likely find a positive correlation between the number of hours you study for a test and the number of correct answers you get (i.e., the more you study, the more questions you get right on the test). On the other hand, the exact same data will give us a negative correlation if we compare the number of hours you study to the number of questions you get wrong (i.e., the more you study, the fewer questions you get wrong). So the way in which you ask the question can determine whether you have a positive or negative correlation, but it should not affect the strength of the relationship.
Since the investigator does not control the variables in correlational research, it is not possible to determine whether or not one variable causes the relationship. In the example used above, it certainly seems that studying more would lead to getting a better grade on a test. But consider another example: can money buy happiness? There is some evidence that wealthy people are happier than the average person, and that people in wealthy countries are happier than those in poorer countries. But does the money affect happiness? Certainly a million dollars in cash wouldn’t help much if you were stranded on a desert island, so what can it do for you at home? People with money can live in nicer, safer communities, they have access to better health care (so they may feel better physically), they may have more time to spend with their family and friends, and so in many ways their lives might be different. We can also look at the correlation the other way around; maybe happy people get more money. If you ran a company, and were going to hire or promote someone, wouldn’t you want to find someone who is friendly and outgoing? Wouldn’t you look for someone who other people will enjoy working with? So, maybe happy people do find it easier to be successful financially. Either way, we simply can’t be sure about which variable influences the other, or even if they influence each other at all. In order to do that, we must pursue experimental research.
Experimental and Quasi-Experimental Designs
The experimental design is usually preferred within psychology, as with any other science. The goal is to control every aspect of the experiment and then manipulate a single variable, thus allowing us to attribute the results to that single manipulation. As a result, experiments allow us to make cause-and-effect statements about the relationships between the variables.
A simple experiment begins with defining the independent variable, the factor that will be manipulated, and the dependent variable, the factor that will be measured. Ideally, we then select our subjects in a random fashion, and assign them randomly to a control group and an experimental group. The experimental group is then exposed to the independent variable, whereas the control group is not. If we have successfully controlled all other variables through random selection of subjects (i.e., all subjects in a specified population have an equal chance of being selected for the study) and random assignment to the control and experimental groups (so that hopefully each group has an equal representation of gender, race, age, intelligence, personal habits, etc.), we should see a difference in the dependent variable that was caused by the independent variable.
Unlike the natural sciences, however, we can seldom control human behavior in the precise ways that true experimental designs require. For example, if we want to study the effects of prenatal exposure to cocaine on personality development, we certainly cannot ask pregnant women to use cocaine. Unfortunately, there are pregnant women who abuse cocaine and other illegal drugs. Therefore, we can try to identify those women, and subsequently study the development of their children. Since a variety of other factors led these women to abuse illegal drugs, we lose the control that is desired in an experiment. Such studies are called quasi-experimental, because they are set up as if we did an experiment, and can be analyzed in similar ways. The quasi-experimental approach has many applications, and can provide valuable information not available otherwise, so long as the investigators keep in mind the limitations of the technique (for the classic discussion of this design see Campbell & Stanley, 1963).
Cross-Cultural Approaches to the Study of Personality
Cross-cultural approaches to studying personality do not really represent a different type of research, but rather an approach to research that does not assume all people are influenced equally by the same factors. More importantly, cross-cultural psychologists recognize that seemingly common factors may, in reality, be quite different when viewed by people of very different cultures. The most obvious problem that arises when considering these issues is the potential difference between cross-cultural and multicultural research. Cross-cultural research is based on a comparison of cultures; two well-known categorizations are Eastern vs. Western perspectives and the somewhat related topic of individualistic vs. collectivistic cultures. However, a multicultural approach tells us that we must consider the true complexity of the human race. What is “Eastern?” Is it Asia, China, Japan, does it include India, and what about Muslim groups of people? Should Buddhism be viewed as an Eastern perspective or a religious perspective? The list goes on and on, because there are so many different cultures in the world. And finally, is it practical to really try coming up with a theory of personality that can encompass all the different groups of people throughout the world? Only by pursuing an understanding of different cultures can psychology truly be considered a global science, and that pursuit has only just begun. Since we have a long way to go, the future is ripe for new students to pursue careers in psychology and the study of personality.
In this video [9:11], personality research methods are explored. Advantages and disadvantages of each method is discussed, as well as exciting new developments in the field.
Text: Kelland, M. (2017). Personality Theory. OER Commons. Retrieved October 28, 2019, from https://www.oercommons.org/authoring/22859-personality-theory. Licensed under CC-BY-4.0.
Supplemental Material: Personality research methods. Society for Personality and Social Psychology. Retrieved from https://youtu.be/lSab-wtpVnQ. YouTube Standard License.
Application of Personality Theory-Assessing Personality
As in the section above on research methods, an extensive discussion of personality assessment is beyond the scope of this textbook. However, this is such an important issue that we will look at it briefly here, and then will take a closer look in some of the chapters throughout the rest of the book.
Personality assessment most commonly occurs in a clinical setting, when an individual is seeking help for some problem, whether it is an adjustment disorder or a potential mental illness. Assessing personality goes beyond this singular role, however. Certainly a clinical psychologist would be using personality assessment in order to understand a patient’s symptoms, provide a diagnosis (if appropriate), and recommend a preferred course of therapy. Similarly, school psychologists use assessment to identify any possible learning disorders and/or adjustment issues as they pertain to the educational environment. But other psychologists use personality assessment for a variety of reasons as well. Industrial/organizational psychologists use personality assessment to identify preferred candidates for particular jobs, career counselors use these assessments in order to provide valid recommendations regarding the choice of a career path, and research psychologists use assessment in their ongoing efforts to correlate certain personality types to observable behavior or other measures. Thus, the assessment tools used to describe and/or understand personality have a wide range of potential applications.
Reliability, Validity, and Standardization
A particular personality assessment is of little value if it has no reliability or validity and if it is not presented in a standardized format. Reliability refers to the likelihood that a test will give essentially the same result on different occasions, or that two versions of the same test will give similar results. Validity refers to whether a test actually measures what it purports to measure. Standardization refers to the manner in which a test is given, which must be the same for every person receiving the test if there is to be any value in comparing the results among different people.
Determining the reliability and validity of a test can be a long and complicated process, involving a variety of statistical methods to confirm the results. During this process the psychologist(s) developing the test will also typically establish norms. Norms are consistent ways in which particular groups score on a test. For example, on measures of aggressiveness, the “normal” level for men may be quite different than the “normal” level for women. Standardization is quite a bit simpler to establish, since the test can include precise instructions dictating the manner in which it is to be given.
Assessing Personality with Objective Tests
The most famous self-report inventory is the Minnesota Multiphasic Personality Inventory (or MMPI). The MMPI is also probably the most widely used psychological test in the world, and it has stood the test of time (it is currently in its second version, a 1989 revision of the 1943 original). The current version consists of 567 true-false questions, which address not only normal personality traits, but psychopathology and the accuracy of the test-taker as well. The test has several built in “lie” scales in case a person were trying to fake a mental illness (e.g., if they were trying to fake an insanity defense to avoid responsibility for a crime) or minimize any symptoms they may actually be experiencing. The questions themselves range from rather simple (e.g., I enjoy drama.) to rather strange (e.g., I am a prophet of God.), but when put all together they provide a highly valid assessment that can easily be scored by computer (hence the popularity of the test, for both reasons). NOTE: Those are not actual questions from the MMPI, but they are based on real questions. The MMPI is an empirically based instrument. That is, interpretations are based on the pattern of responding obtained by various psychiatric samples. Since the standard MMPI was developed for adults and is rather lengthy, an abbreviated version was developed for use with adolescents: the MMPI-A.
A number of alternatives to the MMPI have been developed. The California Psychological Inventory has been available almost as long as the MMPI and, more recently, the Personality Assessment Inventory has become popular. Another important test is Millon’s Clinical Multiaxial Inventory (the MCMI), which was developed in accordance with Millon’s own theories on personality development and personality disorders. The MCMI was designed with certain advantages in mind, including being relatively short compared to the MMPI and being connected with a specific clinical theory. However, since the test was designed specifically to distinguish amongst psychiatric populations, it is not as useful when assessing “normal” individuals (Keller et al., 1990; Groth-Marnat, 2003).
Behavioral assessment and thought sampling are techniques designed to gain an appreciation of what an individual actually does and/or thinks on a day-to-day or moment-to-moment basis. In each case, observers are trained to make precise observations of an individual at precise times. This provides a statistical sample of the individual’s actual behavior and/or thoughts over time. Naturally, the only person who can record an individual’s thoughts is that person himself or herself, but as long as they are carefully informed of the procedure and are fully cooperating, the technique works fine. When applied correctly, the great value of these techniques is that they are truly objective, in other words, they record actual behaviors and actual thoughts.
Assessing Personality with Projective Tests
The two most famous projective tests are the Rorschach Inkblot Technique and the Thematic Apperception Test (or TAT). Both tests involve the presentation of ambiguous stimuli in an attempt to draw out responses from a patient, responses reflecting impulses and/or thoughts that the patient may not even be aware of (i.e., the patient projects their own thoughts and feelings onto the ambiguous stimuli, even if those thoughts and feelings are subconscious).
The Rorschach Inkblots are just that, inkblots on a piece of paper that can look like most anything. An individual being tested is first asked to say what each inkblot looks like, and then they are asked to explain how they saw what they identified. The answer to a single inkblot is not particularly informative, since any one inkblot may remind the person of some particular thing. However, as the patient goes through all 10 inkblots, trends should become apparent to the psychologist that reflect the dominant issues affecting the personality of the patient (again, even if those issues are subconscious and not available to the conscious awareness of the patient). Initially, the Rorschach was reviewed unfavorably and then ignored. Rorschach became depressed, and died only 9 months after the test was published. Eventually, however; the test became more and more popular, and today is certainly one of the most widely recognized psychological tests. However, studies comparing the Rorschach and the MMPI have shown the latter to be far more valid. In an effort to improve both the reliability and validity of the Rorschach technique, there is now a standardized scoring system.
The TAT is similar to the Rorschach, except that it involves actual pictures of people (although they are still very ambiguous drawings) and the patient is asked to tell a story about the people in the picture. There is no objective scoring system for the TAT, so reliability and validity remain arguable, and the test is more famous than popular as an assessment tool. However, it has been shown to have high validity for certain specific research studies, such as studies on the need for achievement, and continues to serve a function in clinical formulations.
As valuable and informative as the well-established psychological tests are, there is certain vital information that simply cannot be addressed with most tests, such as: a person’s appearance, their attitude, facial expressions, ability to communicate with another person, etc. In addition, tests often lead to further questions, or the need for clarification or explanation. In order to address such issues, both in general and in greater detail, clinical interviews are an essential part of the overall personality assessment. Although the results of an interview are somewhat subjective, when viewed in the context of the psychologist’s clinical experience, along with the results of an assessment tool, they provide psychologists with a much more complete understanding of the person whom they are evaluating.
This video [5:48] explains the Rorschach and Thematic Apperception Tests and describes how they are used in the field of personality psychology.
This video [3:56] explores different types of projective and objective tests used to assess personality, including the MMPI, Rorschach Inkblot and Thematic Apperception Test.
This video [7:24] reviews various ways for assessing and making judgments of personality, as well as methods for increasing the accuracy in personality judgments.
Text: Kelland, M. (2017). Personality Theory. OER Commons. Retrieved October 28, 2019, from https://www.oercommons.org/authoring/22859-personality-theory. Licensed under CC-BY-4.0.
Practical Psychology. (2019, July 1). Inkblot (Rorschach) and TAT(Thematic Apperception Tests)-Projective Tests.[Video File]. Retrieved from https://youtu.be/HJVwA6_sqdQ.
Course Hero. (2019, March 15). Personality Assessment | Psychology. [Video File]. Retrieved from https://youtu.be/5tsbb-B8Rs0.
Society for Personality and Social Psychology. (2018, June 6). Personality assessment and judgement. [Video File]. Retrieved from https://youtu.be/5Tr3dMWDsdc.
Cultural Studies in the Field of Psychology
In the first section we briefly examined the concern of many psychologists that the field of psychology has been slow to embrace the value of cross-cultural research (see Lee et al., 1999; Sue, 1999; Triandis & Suh, 2002). This concern is by no means new. In 1936, Ralph Linton wrote that “different societies seem to show differences in the relative frequency of occurrence of the various psychological types” (pg. 484), and in 1973, Robert LeVine suggested that “this is a moment at which even those who are skeptical about the value of culture and personality study might consider stretching their curiosity in this direction” (pg. ix). Throughout this textbook we will examine a number of theorists who emphasized studying cultural differences as a significant part of their careers and, often, their personality theories as well.
However, it remains true that cross-cultural studies in psychology have only recently moved closer to the mainstream of psychological research and clinical practice. As of 2002, the American Psychological Association has “Guidelines on Multicultural Education, Training, Research, Practice, and Organizational Change for Psychologists.” To cite just a few examples of the range of current interest in cross-cultural psychology, we now have a Dictionary of Multicultural Psychology (Hall, 2005) and books on the relationships between culture, mental illness, and counseling (Axelson, 1999; Castillo, 1997), as well as on the relationships between race, class, and the social and personal development of women (Jordan, 1997b; Pack-Brown, Whittington-Clark, & Parker, 1998). There are also major new texts on African American psychology (Belgrave & Allison, 2006) and racism, prejudice, and discrimination in America (Miller & Garran, 2008; Whitley & Kite, 2006).
The fact that studying cross-cultural factors in personality has always been present in the careers and theories of certain individuals, while not becoming a mainstream focus of attention, is more than just a historical curiosity. By emphasizing biological factors (i.e., genetics), Freud’s theory did not allow for cultural differences. Behavioral theorists emphasized environmental factors, a seemingly cultural approach, but they did not allow themselves to address factors beyond immediate scientific control. Thus, they defined with great precision the role of reinforcement, punishment, discriminative stimuli, etc., while not allowing for the richness of cognition and cultural experiences. Likewise, cognitive theorists clung to the scientific approach of the behaviorists, rather than embracing the potential of sociocultural perspectives. In other words, because strict Freudian theorists, as well as behavioral and cognitive theorists, believed that their theories applied to all people equally, they typically chose not to address differences between people. Thus, those who wished to bring sociocultural perspectives on the development of personality into the field of personality theory faced a degree of direct opposition. And yet, their perseverance is now being fulfilled.
In this section we will briefly examine some of the issues facing personality psychologists who wish to examine personality development in a sociocultural context. The United States, Canada, and Western Europe represent only about one tenth of the world’s population. Ralph Linton, a renowned anthropologist with an interest in cultural influences on personality (see Linton, 1945), also edited a book entitled Most of the World: The Peoples of Africa, Latin America, and the East Today (Linton, 1949). Thus, it is essential that we consider the influence of different cultures around the world if we are going to claim that we have really examined human personality in all its variations.
Since the 1990s, a number of general books on psychology and culture have been available (e.g., Brislin, 2000; Lonner & Malpass, 1994; Matsumoto, 1994, 1997; Matsumoto & Juang, 2004; Okun, Fried, & Okun, 1999; Price & Crapo, 2002; Segall et al., 1990). Although all of these books address topics such as the “self” and person-perception, and other various aspects of personality, only a few of them devote an actual chapter or section to the topic of personality itself (Matsumoto & Juang, 2004; Price & Crapo, 2002; Segall et al., 1990), and in each case the topics are fairly specific. There is, however; some older literature on the relationships between culture, society, and personality. We will examine that research in the second part of this section. First, let us examine some of the general principles of incorporating cross-cultural perspectives into the study of personality.
The Challenges of Cultural Research
The first problem faced by those who are interested in the study of culture and personality is the question: What exactly is to be studied? At the most basic level, there are two types of research. Cross-cultural research typically refers to either parallel studies being conducted in different cultures, or similar concepts being studied in different cultures. In contrast, intercultural research is the study of individuals of different cultures interacting with one another (Brislin, 2000; Matsumoto & Juang, 2004; Segall et al., 1990). As you will see in later chapters, some personality theorists consider interpersonal relationships to be the only true domain for studying individual personality. While most of the research done in psychology has been cross-cultural, as the world becomes more and more of a global community the opportunity for, and importance of, intercultural research is rapidly expanding.
Another fundamental problem with the study of culture is our attention to it, or rather, the lack of attention we pay to something that is so deeply ingrained in our daily lives. Richard Brislin suggests the following exercise: write down three answers for someone from a different culture who asks “What should I know about your culture so that we can understand each other better?” (pg. 10; Brislin, 2000). Because we simply take our cultural influences for granted, it proves quite difficult for us to think that they need to be identified or explained. For example, freedom of speech is a cherished right in America. Consequently, we often speak our minds. If I am upset about some new college policy, I might say very negative things about the administration of our college, even about particular administrators. It does not mean I intend to be disrespectful, or that I dislike those individuals, or that I won’t say positive things about them when I agree with the next new policy. It is simply an expression of one of the great freedoms in our society: the right to speak out. However, someone from a different culture, particularly a collectivist culture, might be shocked at my apparent disrespect toward my “superiors.”
The next important issue is the difference between emic and etic tasks or behaviors. Simply put, emic tasks are those that are familiar to the members of a given culture, whereas etic tasks are common to all cultures. In an elegantly simple, yet revealing study, Irwin, Schafer, & Feiden (1974) demonstrated these phenomena in two cultures: American undergraduates and Mano rice farmers (from Liberia). The American college students were consistently better at performing the Wisconsin Card Sort, a well-known psychological test measuring cognitive reasoning skills, which relies on geometric shapes and color. The Mano farmers, however; were consistently better at sorting different categories of rice. Thus, the ability to sort items into categories appears to be an etic task (most likely common to all humans, regardless of culture), whereas the more specific abilities to sort by geometry and color (common to American college students) or type of rice grain (common to Mano farmers in Liberia) is an emic task that requires familiarity. Thus, if we made a judgment about the Mano farmers’ cognitive abilities based on the Wisconsin Card Sort, we would clearly be making a mistake in comparing them to Americans, due to the unfamiliarity of the particular task.
Another important aspect of cross-cultural research, which may involve applying our understanding of etics and emics, is the issue of equivalence. Is a concept being studied actually equivalent in different cultures? In other words, does a concept mean the same thing in different cultures; is the comparison valid? For example, an etic related to intelligence is the ability to solve problems. So how might we compare different cultural groups? Would the speed with which they solve a problem make sense as a measure of intelligence? Such an answer would be emic, and therefore valid, in America (where we typically value independence and competition). However, among the Baganda of Uganda, slow and careful thought is the emic. Among the Chi-Chewa of Zambia, the emic is responsibility to the community, i.e., solving the problem in order to best get along with other people. Thus, the speed at which people solve problems is conceptually equivalent, since it is the way in which people in each culture identify those individuals who are considered intelligent (Brislin, 2000). However, we cannot compare the actual speed of reporting a solution to others, as this is viewed quite differently in each culture.
One particular type of equivalence that raises a very interesting problem is that of translation equivalence. Psychologists often want to use tests developed in their own language with people of a different culture who speak a different language. Translating a test from one language to another can be a difficult task. The best way to assess translation equivalence is through back translation. In this procedure, one person translates the test, or survey, into the foreign language, and then a different person translates the foreign language test back into the original language. The original test can then be compared to the back translated test to see how closely they are worded. Ideally they would be identical, but this is seldom the case. To give you a simple example, when I was in graduate school, we had a student from Taiwan join our research group. One day I asked her to translate my last name, Kelland, into a Chinese character. When she had done that, I asked her how she would translate that particular Chinese character into English for someone who was not Chinese. She translated the character as Kwang. Despite the first letter, I hardly consider Kwang to be a reasonable translation of Kelland, but she didn’t seem to think of this as much of a problem (perhaps revealing another cultural difference!). When the process of back translation is used successfully, which may involve working back and forth with the translations, it has the effect of decentering the test from the original language. Specifically, that means that the test should be free of any culturally emic references or aspects that interfere with the translation equivalence of the different versions of the test (Brislin, 2000; Matsumoto & Juang, 2004).
While the list of issues pertaining to cross-cultural research goes on, let’s consider just two more specific issues: cultural flexibility and cultural response sets. Cultural flexibility refers to how individuals are willing to change, or adapt, in situations in which they know there are cultural differences. For example, American businesspeople can stand about 15 minutes of small talk before getting down to business. Their Japanese counterparts, in contrast, consider it important to get to know their business partners, and they are comfortable with hours of conversation about a variety of topics. This would, of course, be an important consideration for anyone studying the relationship between individual personality and success in business situations in this intercultural setting. Cultural response sets refer to how a given culture typically responds. If a given culture is more reserved, and they are asked to rate the importance of some value in comparison to how a more open culture rates that value, a difference in the rating may reflect the cultural difference in responding, rather than the degree to which people in each culture value the variable being measured (Brislin, 2000; Matsumoto & Juang, 2004).
Finally, in light of these challenges, it may be particularly important to conduct cross-cultural validation studies. Rather than testing hypotheses about specific cultural differences, cross-cultural validation studies are used to examine whether a psychological construct that was identified in one culture is meaningful and equivalent in another culture (Brislin, 2000; Matsumoto & Juang, 2004). For example, as we will see later in the reading, Erik Erikson did not feel confident in proposing his eight stages of development (the psychosocial crises) until he had confirmed his observations in two separate Native American tribes. He was able to gain the trust of these groups, and thus able to closely observe their child-rearing practices, thanks to the anthropologists who introduced him to the tribes they had been studying for a long time.
Anthropologists have done much more for psychology than merely introducing some psychologists to cultural issues and unique cultural groups. Some of them have had their own interests in personality. Many anthropologists, as well as some psychologists, have relied on ethnographies to report detailed information on the customs, rituals, traditions, beliefs, and the general way of daily life of a given group. They typically immerse themselves in the culture, living for an extended period of time with the group being studied (this helps get past the anxiety of being observed or any lack of cultural flexibility). Comparing the ethnographies of different groups can help guide cross-cultural psychologists in determining the likelihood that their cross-cultural studies are valid (Matsumoto & Juang, 2004; Segall et al., 1990).
This video [7:42] explores the following three concepts: Conceptualization of personality across cultures; Cross-cultural research informing our understanding of personality; Future research in culture and personality.
Kelland, M. (2017). Personality Theory. OER Commons. Retrieved October 28, 2019, from https://www.oercommons.org/authoring/22859-personality-theory. Licensed under CC-BY-4.0.
Society for Personality and Social Psychology. (2018, June 6). Personality and culture. [Video File]. Retrieved from https://youtu.be/YC7LxSSrJYE. Standard YouTube License.