What is the first thought that comes to mind when you hear or see the word “personality”? Do you generally use the word to describe a person’s character traits and behaviors? Do you refer to your best friend as a “good person”? Or perhaps you have a co-workers “with a lot of drama in her life, but she has always been a warm, caring person”? Or maybe you have a family member you describe as “polar opposite in interests, clashing views on politics, and is often short-tempered and with no filter”?
If you have ever described a person’s character in detail, you are yet another of the vast majority of human beings who intrinsically assess other human beings’ attributes: what makes us unique to each other, how do we vary in temperaments, why we are attracted to or put off by other personalities, etc. This also means we are intrinsically “lay theorists.” That is, from our experiences interacting with other people, we use our developed cognitive abilities to understand, or at least try to understand, how we relate to and differ from each other (Cervone & Pervin, 2013).
However, while we lay theorists may build solid analytic skills that fundamentally assess personality differences, the scientific approach to personality takes observations about the natural world, evolution, biology, a complex variety of behaviors, and human interaction; combines those factors into a single hypothesis; tests the hypothesis in various ways to determine repeatability; draws a conclusion based on the results; and, if the results are repeatable and established as observed fact, theories are constructed to describe the observed facts in more detail (Cervone & Pervin, 2013).
In this paper, we will start by covering some basics on how science defines personality. Then, we will explore three common methods – case studies, correlational studies, and experimental studies – used to study personality, including the advantages and disadvantages of each method. Lastly, we will briefly explore how each method differs.
First, how exactly does science define personality? According to the American Psychological Association, the character traits, thoughts, behaviors, and feelings that help us define an individual also help us define personality (APA, 2020). Based on the Latin word “persona” – which literally means “mask” – the definition of personality has grown from the first stage actors who wore makes to symbolize character traits, to modern scientific studies that not only explain personality nuances, but also have developed theories to explain observed facts (Dean, 2020).
Science further breaks down personality into two main perspectives: idiographic and nomothetic. The idiopathic perspective focuses on what makes individuals psychologically unique. Conversely, the nomothetic perspective shows similarities between individuals and the traits that are universal to all people. Each perspective has its place in scientific inquiry, and both help solidify the various theories about personality (McLeod, 2017).
Of course, scientific theories cannot be fully vetted without using methods to conduct scientific studies. Let’s start with the first of the three common methods for studying personality: case studies. As the term implies, a case study involves investigating a hypothesis by observing individuals or groups in a specific setting. This setting is often organized with an equally specific purpose (Lumen, 2020).
For example, if the hypothesis is that people who live in a rainy city are more prone to depression than people who live in sunny conditions most of the year, a case study could have a group of individuals in each climate view pictures of life in sunny versus rainy climates, followed by the individuals describing how each picture made them feel. The data collected is then used to support additional study methods, or in addition to other case studies that address the same hypothesis from other angles (Crowe et al, 2011): each individual’s demographics, are any of the individuals genetically predisposed to depression, do they feel depressed in other circumstances or just in overcast / rainy climates, and so on.
Case studies have several key advantages, including that they can be cost effective on a smaller budget, they don’t necessarily need to be conducted at a specific location, and they usually target a specific group or individual with traits that relate to the study criteria. On the other hand, collecting data for a case study can be cumbersome; and it opens the door for bias: Are the participants being honest in their answers, are they being selectively biased? (Gaille, 2018).
Next up: correlational studies. Simply put, correlational studies take two variables and determine how they relate to each other (Formplus, 2020). For instance, let’s say our hypothesis is that high-glycemic / simple sugar foods contribute to hyperactivity disorders. A correlational study would show the relationship between high-glycemic diets and hyperactivity.
From there, correlational studies are split into three categories: Positive Correlational Research, Negative Correlational Research, and Zero Correlational Research. Positive research shows what happens when one of two related variables increases or decreases in value, and how that affects the other variable. Negative research takes two opposite variables and measures how an increase in one can cause a decrease in the other, or vice versa. Zero research involves two unrelated variables, which may not have any affect at all on each other (Formplus, 2020).
Based on those approaches, and how correlational studies work in general, collecting data is not limited to the lab environment. In fact, data in correlational studies are often collected in public / non-lab settings; and they are less prone to being biased (particularly if the subjects are not aware of the study). On the flip side, similarly to case studies, correlational studies can be inefficient and time intensive. In addition, although two variables may have a distinct connection, it can be difficult to figure out which variable is the more dominant / influential (Gaille, 2020).
This leads us to the third and final primary method of scientific study: experimental studies. As we know that experiments are a core part of the scientific method, they can also produce quite accurate results. Specifically, experimental studies are typically conducted in a well-controlled environment, and they include studying independent and dependent variables within that same environment. Independent variables change from experiment to experiment within a specified series, while dependent variables show the results caused by manipulating the independent variables. What’s more, experimental studies often categorize the two different variables into control groups versus random assignments (Lumen, 2020).
Because experimental studies can be reliably accurate, especially because they involve a control, they often lead to precise results. Moreover, they are not just limited to psychology; they are now used in other fields as well, and with variables that are specific to the field and to the experiment itself. On the other hand, experimental studies are largely conducted using rather artificial circumstances – which may cause the results to be skewed or more prone to human error (Flow Psych, 2015).
Overall, case studies, correlational studies, and experimental studies each contribute substantially to scientific research. And where they differ from each other can help bridge gaps in a scientific study, or at least show where the clear gaps exist and how they may need to be studied further. For instance, while a case study may be useful in observing how a group reacts to watching violent movies, using a questionnaire or other possibly other subjective format may yield biased answers (Crowe et al, 2011).
Meanwhile, an experimental study on watching violent movies offsets the case study by providing a controlled environment and requiring a more rigorous testing method to gather data. Then, correlational studies can aptly bridge the experimental and case study methods by establishing a more direct relationship between two variables. Example: Is there a correlation between people who watch violent movies and people with generally aggressive tendencies (Formplus, 2020).
Collectively, all three methods show different sides of the same puzzle to solve. And as this paper has pointed out, using all methods available can help separate fact from fiction and produce highly accurate conclusions – which lead to building more effective scientific theories.
References
Cervone, D., & Pervin, L. A. (2013). Personality: Theory and research (12th ed.). Hoboken, NJ: John Wiley & Sons, Inc.
American Psychology Association. (2019). Personality. https://www.apa.org/topics/personality/
McLeod, S. (2017). Theories of Personality. https://www.simplypsychology.org/personality-theories.html
Dean, M. (2020). All About Personality: Psychology Definition And Examples. https://www.betterhelp.com/advice/psychologists/all-about-personality-psychology-definition-and-examples/
Crowe, S., Cresswell, K., Robertson, A., Huby, G., Avery, A. (2011). The case study approach. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3141799/
Lumen. (2020). Types of Research Studies. https://courses.lumenlearning.com/boundless-psychology/chapter/types-of-research-studies/
Formplus. (2020). Correlational Research Designs: Types, Examples & Methods. https://www.formpl.us/blog/correlational-research
Gaille, B. (2018). 12 Case Study Method Advantages and Disadvantages. https://brandongaille.com/12-case-study-method-advantages-and-disadvantages/
Gaille, L. (2020). 12 Advantages and Disadvantages of Correlational Research Studies. https://vittana.org/12-advantages-and-disadvantages-of-correlational-research-studies Flow Psychology. (2015). 7 Advantages and Disadvantages of Experimental Research. https://flowpsychology.com/7-advantages-and-disadvantages-of-experimental