By Jonny Lupsha, News Writer

The “Big Five” personality test appears to be less reliable than thought, according to a new study published in the journal Science Advances. Once thought to be an accurate gauge of behavior, the test seems to be often ineffective in some regions of the world. So what is a personality and how is it studied?

One of the biggest tests to determine someone’s personality, nicknamed the “Big Five” test, provides statements with which the test subject can respond that they agree, disagree, or are neutral. While incredibly popular in the West for decades, a new study shows that the test often misfires in countries that aren’t western, educated, industrialized, rich, and democratic (WEIRD). The inaccuracy of the Big Five’s measuring and interpretation of personality traits in non-WEIRD countries has led many to ask what exactly a personality is and why it differs from person to person.

Defining Personality

In order to determine what exactly a personality is—and isn’t—it can help to look at some popular definitions. “As psychologists use the term, personality involves those psychological characteristics that give people a distinct and somewhat stable and predictable style of responding to the world,” said Dr. Mark Leary, Garoznik Family Professor of Psychology and Neuroscience at Duke University. He added that the qualifier “somewhat stable” is needed because nobody behaves exactly the same way their entire lives. “Well-adjusted people are flexible enough to accommodate to the demands of the situations in which they find themselves. Yet, as we look at your behaviors across different situations and over time, we can see that you have certain tendencies—tendencies to view things in certain ways, to have certain emotional reactions, to be motivated by particular things, and to behave in particular ways.”

In addition, our personalities are shaped by both internal and external factors. “A basic assumption of psychology is that to understand people fully, we have to focus both on their personal psychological characteristics and on the nature of the situation they are in at the moment,” Dr. Leary said. “Wherever you go, you carry with you a large, complex set of psychological characteristics: traits, beliefs, emotional tendencies, motivations, other attributes that predispose you to respond in certain ways. But how you act also depends on the particular situation you’re in at the time, not only the physical environment but also the social context.”

Personality Psychology vs. Social Psychology

Dr. Leary said that historically speaking, behavioral psychology is studied in two separate fields. “The field of personality psychology has focused mostly on internal psychological traits and processes, and the field of social psychology has focused mostly on social, situational determinants of behavior,” he said. “Although all behavior is a function of the characteristics of the person and the characteristics of the situation, from the earliest days of behavioral science, researchers have debated which of these influences is most important in understanding human behavior.”

So which is it? The answer depends on the “strength” of the situation. According to Dr. Leary, a strong situation is defined as “one in which situational pressures are so strong that there’s little or no room for personality to play a role.” He cited the example of sitting quietly while in a place of worship—it’s simply what’s done, as has been understood as the norm for generations.

On the other hand, a weak situation allows far more room for one’s personality to show, which Dr. Leary explained with a visit to the beach. “People do all sorts of things at the beach and for all kinds of reasons: they might be swimming or playing in the sand, or reading a book, or tossing a Frisbee, or jogging, or walking, or collecting shells, or talking to other people, or just lying in the sun,” he said. “The beach provides a relatively weak situation, so differences among people—in what they decide to do—are easy to see.”

The Big Five test may be on its way out as a universal decoder of human personality, but psychology has a firm definition of what a personality is and often has reliable indicators of why we are the way we are. Whether focusing on the individual or the social context of the individual’s situation, psychology still adheres to scientific principles and is based on sound research to help analyze behaviors and offer help where help is needed.

Dr. Mark Leary contributed to this article. Dr. Leary is Garonzik Family Professor of Psychology and Neuroscience at Duke University. He earned his bachelor’s degree in Psychology from West Virginia Wesleyan College and his master’s and doctoral degrees in Social Psychology from the University of Florida.