What is Personality?

One of the most important sources of individual differences is personality, which refers to our relatively stable patterns of thinking, feeling, and behaving. Our personalities differentiate us from other people, and understanding someone’s personality gives us clues about how that person is likely to act and feel in a variety of situations, including at work.

Personality Traits

The dimensions along which people differ in their characteristic patterns of thinking, feeling, and behaving are known as personality traits. Trait psychologists argue that personality can be described using a limited number of these dimensions, such as extraversion, conscientiousness, and agreeableness. Each person falls somewhere along each dimension and may be relatively low, moderate, or high on a given trait.

An important feature of personality traits is that they reflect continuous distributions rather than distinct personality types. This means that when we talk about introverts and extraverts, we are not really talking about two distinct types of people who are completely and qualitatively different from one another. Instead, we are talking about people who score relatively low or relatively high along a continuous distribution. In fact, when personality psychologists measure traits like extraversion, they typically find that most people score somewhere in the middle, with smaller numbers showing more extreme levels.

Traits describe stable patterns of behavior that persist for long periods of time.^[1] Importantly, these stable patterns can have broad-ranging consequences for many areas of our life.^[2] For instance, think about the factors that determine success in college. If you were asked to guess what factors predict good grades, you might guess something like intelligence. This guess would be correct, but we know much more about who is likely to do well. Specifically, personality researchers have also found the personality traits like conscientiousness play an important role in college and beyond, because highly conscientious individuals tend to study hard, get their work done on time, and are less distracted by nonessential activities that take time away from school work. In addition, highly conscientious individuals are often healthier than people low in conscientiousness because they are more likely to maintain healthy diets, to exercise, and to follow basic safety procedures like wearing seat belts. Over the long term, these consistent patterns of behavior can add up to meaningful differences in health and longevity. Thus, personality traits are not just a useful way to describe people, they also help predict how effective a worker someone will be, how long he or she will live, and the types of jobs and activities they will enjoy.

Stability of Personality Traits

If personality is stable, does this mean that it does not change? You probably remember how you have changed and evolved as a result of your own life experiences, the style of parenting you were exposed to, successes and failures you had in high school, and other life events. In fact, our personality does change over long periods of time. For example, we tend to become more conscientious (organized and dependable) and more emotionally stable between the ages of 20 and 40, whereas openness to new experiences may begin to decline during this same time.^[3] In other words, even though we treat personality as relatively stable, changes occur. Moreover, even in childhood, our personality shapes who we are and has lasting consequences for us. For example, studies show that part of our career success and job satisfaction later in life can be explained by our childhood personality.^{[4], [5]}

The Five-Factor Model of Personality

Trait psychology rests on the idea that people differ from one another in terms of where they stand on a set of basic trait dimensions that persist over time and across situations. The most widely used system of traits is called the Big Five, or the Five-Factor Model (Video 1).^{[6], [7], [8]}

The Big Five comprises five major traits (Figure 1): openness, conscientiousness, extraversion, agreeableness, and neuroticism. Each of the major traits from the Big Five can be divided into facets to give a more fine-grained analysis of someone’s personality. Click on each trait below to learn more, particularly as each relates to the workplace.

Scores on the Big Five traits are mostly independent. That means that a person’s standing on one trait tells very little about their standing on the other traits of the Big Five. For example, a person can be extremely high in extraversion and be either high or low on neuroticism. Similarly, a person can be low in agreeableness and be either high or low in conscientiousness. Thus, in the Five-Factor Model, you need five scores to describe most of an individual’s personality. Figure 2 provides characteristics of people who would score high and low on each of these traits.

Myers-Briggs Type Indicator

Aside from the Big Five personality traits, perhaps the most well-known and most often used personality assessment is the Myers-Briggs Type Indicator (MBTI). The MBTI was developed in 1943 by a mother–daughter team, Isabel Myers and Katherine Cook Briggs. Its objective at the time was to aid World War II veterans in identifying the occupation that would suit their personalities. Since that time, MBTI has become immensely popular, with some 2 million people taking the test annually.

The MBTI relies on the psychological theories of Carl Jung and works on the basic assumption that individuals fall into fairly distinct classes, or types, of personalities. In MBTI, people are grouped using four dimensions. Based on how a person is classified on these four dimensions, it is possible to talk about 16 unique personality types, such as ESTJ and ISTP (Table 1).

A person’s classifications within each of these four categories are then combined to create 16 unique personality types identified by the MBTI. Four-letter acronyms are used to name these personality types, with the letters representing the corresponding trait within each category. For example, a person who exhibits characteristics of extraversion, intuition, thinking, and judging would be classified as ENTJ.

While the MBTI has been popular for decades, its use has been heavily criticized (Video 2). In particular, critics of the MBTI point to data that shows that as much as 50 percent of an individual’s MBTI classification will change from test to test with as little as only four or five weeks between tests.^[9] Another potential weakness of the tool is that it divides individuals into distinct classes for each category, not indicating how strong an individual’s preference is toward that end of the spectrum. For instance, if an individual is slightly more introverted than extraverted, he or she receives the same classification as someone who is intensely introverted. The distinction between two such individuals is not represented.

Proponents of the MBTI caution against its use for the purposes of hiring or promoting employees, and suggest that the MBTI is intended as a learning tool. Notably, administration of the MBTI is strictly controlled by the Myers-Briggs Company and requires costly certification to administer. Thus, The Myers-Briggs Company and certified administrators have strong incentives to defend it.

Beyond Personality Traits

Is our behavior in organizations dependent on our personality traits? To some extent, yes, and to some extent, no. At work, we have jobs to do and roles to perform. Therefore, our behavior may be more strongly affected by what is expected of us, as opposed to how we want to behave. When people have more freedom at work, however, their personality will likely become a stronger influence over their behavior.^[10]

Free Traits and Personal Projects

According to Brian Little, a prominent personality psychologist, we are often able to override our biological make-up through the adoption of what he refers to as free traits. Free traits, or aspects of a person that enable them to act in a ‘non-typical’ way to achieve a particular goal (e.g., an introverted person acting in an extroverted fashion to advance a particular project), allow us to act in different ways to our natural selves. We call on these free traits to meet the demands of different situations and achieve projects and goals that are important to us. Free traits are in contrast to fixed traits, which are our natural tendencies and predispositions.

Little recommends that we think of ourselves as amateur scientists who are continually exploring and testing the world around us to discover what works and what doesn’t. We do and say things, and then we observe the reactions to these things and unconsciously store the results. We apply what we learn from our experiments to the advancement of what Little describes as our personal projects, or the goals and pursuits that ultimately drive people’s behavior.

The personal projects in question might be big (such as career ambitions) or small (like cleaning one’s work space), but they form the foundation of our day-to-day behavior and our relationships with our families, friends, and coworkers. Sometimes our personal projects requires us to act out of character by engaging free traits; other times, we can just be ourselves. Little proposes that the successful pursuit of core projects that are meaningful, manageable, supported by others, and generate positive feelings can greatly impact our happiness and the quality of our lives.

Little’s personal project framework has important implications for organizational life. When employees engage in free-trait behavior—stretching beyond their usual preferences to pursue important goals—it can strain well-being and physical health. Over time, those costs may result in lower productivity, weaker performance, and more time away from work. Organizations should therefore treat free-trait enactment and personal projects as key forces shaping behavior, and design work accordingly. For instance, organizations might offer employees opportunities to recover, such as by providing quiet spaces to decompress and regain energy after demanding, out-of-character efforts.

Chapter Review

Flashcards

Practice Questions

Optional Resources to Learn More

	Articles
	Arts Managed: Personal Projects
	Excerpt: Me, Myself, and Us by Brian Little
	Psychology Today: Goodbye to MBTI, the Fad That Won’t Die by Adam Grant
	The Atlantic: People Don’t Actually Know Themselves Very Well by Adam Grant
	The Atlantic: The Virtuous Cycle of a Happy Personality by Arthur Brooks
	Books
	Me, Myself, and Us by Brian Little
	Psych: The Story of the Human Mind by Paul Bloom
	Quiet: The Power of Introverts in a World That Can’t Stop Talking by Susan Cain
	Who Are You, Really?: The Surprising Puzzle of Personality by Brian Little
	Podcasts
	Rethinking with Adam Grant: The Science of Personality and the Art of Well-being with Brian Little
	Work Life with Adam Grant: Your Hidden Personality
	Videos
	Society for Personality and Social Psychology: Insights into Personality Psychology (video series)
	GOTO Conferences: Personalities at Work by Brian Little
	Knowledge at Wharton: The Science of Personality
	Practical Psychology: The Big 5 OCEAN Traits Explained
	Practical Psychology: Trait Theory – History of Personality Psychology
	Practical Psychology: What is Personality?
	TED: Who are you, really? The Puzzle of Personality by Brian Little
	TED-Ed: Do personality tests work?
	Yale Open Courses: Why are People Different? by Paul Bloom

Attributions

Source Material Attributions

Diener, E. & Lucas, R. E. (2026). Personality traits. In R. Biswas-Diener & E. Diener (Eds), Noba textbook series: Psychology. Champaign, IL: DEF publishers. https://nobaproject.com/modules/personality-traits. Licensed with CC BY-NC-SA 4.0.

Donnellan, M. B. (2026). Personality stability and change. In R. Biswas-Diener & E. Diener (Eds), Noba textbook series: Psychology. Champaign, IL: DEF publishers. https://nobaproject.com/modules/personality-stability-and-change. Licensed with CC BY-NC-SA 4.0.

Roe, J. J., & Aspinall, P. A. (2012). Adolescents’ daily activities and the restorative niches that support them. International journal of environmental research and public health, 9(9), 3227-3244. Licensed with CC BY 3.0.

Spencer, A. & Lumen Learning. Personal Values and Personality at Work. Principles of Management. https://courses.lumenlearning.com/suny-mcc-supervision/chapter/personal-values-and-personality-at-work/. Licensed with CC BY: 4.0.

University of Cambridge (2015, February 20). Acting ‘out of character’ in the workplace. https://www.cam.ac.uk/research/features/acting-out-of-character-in-the-workplace. Licensed with CC BY-NC-SA 4.0.

University of Minnesota (2017). Understanding People at work: Individual differences and perception. Organizational behavior. University of Minnesota Libraries Publishing. https://open.lib.umn.edu/organizationalbehavior/. Licensed with CC BY-NC-SA 4.0.

Media Attributions

Figure 1: Donnellan, M. B. (2026). Big 5 personality traits. Noba. https://nobaproject.com/modules/personality-stability-and-change. Licensed with CC BY-NC-SA 4.0.

Figure 2: Rice University. (2020, April 22). Five Factor Model. OpenStax. https://openstax.org/books/psychology-2e/pages/11-7-trait-theorists. Licensed with CC BY-NC-SA 4.0.

Video 1: The Right Questions. (2024, March 12). How to define your personality with the Big Five traits (OCEAN) test [Video]. YouTube. https://youtu.be/8Hz0pVx9DfI

Video 2: Vox. (2015, October 8). Why the Myers-Briggs test is totally meaningless [Video]. YouTube. https://youtu.be/Q5pggDCnt5M