The Science Behind the Five Major Personality Types

From the lecture series: Why You are Who You Are — Investigations into Human Personality

By Mark Leary, PhD, Duke University

The English language contains more than 3,000 words that refer to personality characteristics of various kinds. This shows the extent to which we all spend thinking and talking about people’s personality characteristics. But having all of these words actually creates a problem for studying and understanding personality.

What are the different personalities? concept
(Image: XiXinXing/Shutterstock)

Isolating The Five Major Personality Types

Clearly, there aren’t 3,000 different personality characteristics. Many of these words—in any language—are synonyms or near-synonyms for the same traits. So, if someone is nervous a great deal of the time, we can say that they’re a nervous person, that they’re anxious, tense, or neurotic. These words might have slightly different shades of meaning, but they all refer to the same characteristic.

With so many different words that refer to personality characteristics, researchers have faced a serious challenge in trying to figure out how many basic personality traits there really are. What are the big five personality traits?

This is a transcript from the video series Why You are Who You Are: Investigations into Human Personality. Watch it now, on Wondrium.

This has been a surprisingly difficult task, and it’s made even more challenging by the fact that not all personality traits are created equal. Some characteristics are more important than others in understanding people’s behavior and in predicting important outcomes in people’s lives, such as the nature of their relationships with others, the degree to which they’re successful at achieving their goals, their psychological well-being, and their health.

To understand a person’s behavior knowing how dependable and honest they are is more useful than knowing whether they’re tidy or excitable.

For example, it usually tells you more about what a person is like to know whether they’re dependable or honest than it is to know whether they are tidy or excitable. They account for more variability in people’s behavior, and they have more important implications for people’s lives. It helps us to understand a person’s behavior, the choices they make, and how they get along with other people.

Learn More: What Is Personality?

Psychological Researchers and Factor Analysis

When psychological researchers started to tackle the question of basic personality traits in the 1930s and 40s, they turned to what was then a newly-developed statistical procedure called factor analysis. Factor analysis is a statistical technique that can be used to identify the basic dimensions that underlie a set of variables that are correlated or related to each other. Understanding what it does is important for understanding basic personality traits.

Factor analysis is a statistical technique that can be used to identify the basic dimensions that underlie a set of variables that are correlated or related to each other.

Imagine that we asked a large number of people to rate themselves on 100 characteristics that describe various aspects of personality. They rate themselves on words such as enthusiastic, critical, dependable, anxious, reserved, sympathetic, careless, calm, outgoing, assertive, creative, maybe even excitable.

We could have people rate themselves on all 100 of these characteristics on a five-point scale that ranges from “Not at all” to “Extremely.”

Now imagine that we correlated people’s ratings on each pair of these 100 characteristics. A correlation is a statistic that tells us how strongly two variables are related to each other. For example, across all of our respondents, we could calculate the correlation between people’s ratings of how enthusiastic they are and how assertive they are. This correlation would tell us how strongly people’s ratings of enthusiasm are related to their ratings of assertiveness.

 analyzing different features and assets of people
Analyzing correlations between people’s characteristics gives an idea about personality traits. (Image: desdemona72/Shutterstock)

We could then calculate a correlation between every pair of those 100 ratings—that’s 4,950 different correlations that show how strongly each of these 100 characteristics is related to each of the other characteristics.

If we look at all of these correlations among people’s ratings of the 100 characteristics, we’ll find that some of the characteristics correlate highly with each other, while other characteristics don’t.

Learn More: Traits That Shape How You Think

For example, how people rate themselves on the characteristic, “dependable,” probably correlates highly with how they rate themselves on the characteristic, “organized.” People who are dependable also tend to be organized, and people who are undependable also tend to be disorganized. Consequently, these two ratings of dependable and organized will probably correlate highly with each other.

When you find that ratings on one characteristic are highly correlated with ratings on another characteristic, a reasonable conclusion is that these two ratings are tapping into the same basic trait. If people who rate themselves highly on consistently rate themselves highly on Y, then perhaps X and Y aren’t two different things at all, but rather two ratings of the same general characteristic.

Now, if we were to actually look at a table of 4,950 correlations among people’s ratings on 100 characteristics, we wouldn’t be able to make much sense of things, but that’s where factor analysis comes in. Factor analysis takes information about how all of these ratings correlate with each other and mathematically determines how many basic traits are being measured. So, factor analysis has been an indispensable tool for identifying basic personality traits from the hundreds of words that we use to describe personality.

Factor analysis takes information about how all of these ratings correlate with each other and mathematically determines how many basic traits are actually being measured.

The “Big Five”

By the 1980s, a high degree of consensus had emerged that human personality is characterized by only five basic personality traits. These five traits became known as “The Big Five”, and they’ve been the focus of an incredible amount of research. Many other traits exist, but these five have become recognized as the most important traits for understanding people’s personalities and behavior. But, before we discuss these 5 traits, what exactly is a personality trait?

What is a Personality Trait?

Personality trait concept
(Image: StunningArt/Shutterstock)

As psychologists use the term, a personality trait is an internal, psychological characteristic that involves the tendency to respond in a particular way.

Think about your behavior: Do you tend to be outgoing or more reserved in social situations? You probably aren’t either one all the time—sometimes you’re more outgoing, and sometimes you’re more reserved. But if we followed you around and watched you in many different situations, we’d probably find that you show a tendency to lean one way or the other.

You might tend to be more outgoing, or you might tend to be more reserved. The fact that you show a particular tendency in how you respond across situations suggests that you possess some psychological characteristic, or perhaps a set of characteristics, that predisposes you to react in one way or another. Therefore, we would say that you have a trait that predisposes you to tend to be outgoing, reserved, etc.

By definition, the concept of a trait implies that a person will show a certain degree of consistency in his or her thoughts, feelings, or behaviors across different situations.

If you have a particular trait, we ought to be able to see a tendency for you to respond in a particular way across different situations. Of course, even when people have a trait, they don’t act the same way all the time. Different situations call for different kinds of behaviors, and people who act exactly the same way all the time don’t adapt to the demands of specific situations.

No matter how outgoing you are, you must sometimes be reserved; and no matter how reserved you usually are, situations sometimes require you to be sociable. So, nothing in the concept of trait implies that a person acts the same way all the time; that would be a sign of a personality disorder. Again, having a trait simply means that people show a tendency to respond in a particular way.

…having a trait simply means that people show a tendency to respond in a particular way.

The concept of trait also implies a certain degree of consistency over time in how people tend to respond. People’s personality traits can and do change over time, at least within limits. But over the short run, we see stability in their traits. If you tend to be outgoing this month, we aren’t likely to find that you have become consistently reserved a few months from now. It can happen, for example, if people experience a traumatic event, but under normal circumstances, personality shows a good deal of stability over time.

Learn more about consistency and stability of personality

The Difference Between a Personality Trait and a Personality Type

A trait can be visualized as a dimension or a continuum, and people can fall anywhere along the trait dimension from very low to very high. When psychologists measure any particular trait, people’s scores can range from very low scores to very high scores. In the case of sensation-seeking, for example, scores on one measure of sensation seeking can range anywhere from 0 to 40.

In contrast, when we talk about a personality type, we are categorizing people into a small number of discrete categories or groups, sometimes only two. Instead of giving you a score on a continuous measure of sensation-seeking, we could simply classify you as being low or high in sensation-seeking, or we could classify you as a dominant or submissive person, as depressed or not depressed, or as an extrovert versus an introvert.

In each case, we have classified you as a type of person—a low sensation seeker, a dominant person, an introvert, or whatever—by putting you in a category.

Personality researchers almost never talk about types because true personality types almost never exist.

Personality researchers rarely talk about types because true personality types almost never exist. That is, there are not many psychological characteristics in which people naturally and cleanly fall into one category or another. Instead, people vary from one another across all levels of a trait continuum.

You and your neighbor might both be low in sensation-seeking, but maybe you’re much lower than your neighbor is, and researchers want to measure and explain that difference. Putting both of you in the low sensation-seeker box throws away a great deal of information and nuance that’s important in understanding people’s behavior.

What is The Myers-Briggs Indicator Test?

Many people have taken the Myers-Briggs Type Indicator at some point in their life. The Myers-Briggs is used a great deal to help people understand their personality, particularly in work organizations to help employees understand how they differ from their coworkers. It helps people recognize differences in how people approach situations and problems and thus helps people work together more effectively.

A chart with descriptions of each Myers-Briggs personality type as well as instructions for how to determine one's type.
Myers-Briggs Type Indicator (Image: Jake Beech/Public domain)

But the Myers-Briggs Type Indicator is, as its name indicates, a type indicator. It tells you what type of person you are on four characteristics: extrovert vs introvert, sensing versus intuition, thinking versus feeling, and judging versus perceiving. You don’t need to understand what those terms mean, but after people take the Myers-Briggs, they get a four letter code that tells them which of 16 types they are.

If you have taken the Myers-Briggs, you can probably remember your type—you’re an ISTJ, an INFP, an ESTP, or whatever, and that code reflects your type.

As a way to provide people with insights about their own and other people’s personalities, the Myers-Briggs is quite useful. It not only gives people an insight into their personality, but it also helps people understand others. For example, once I realize that a coworker and I have different approaches to the world—that we’re different types—I can work within those differences rather than just assume that the coworker is being obstinate, doesn’t like me, or is mentally unbalanced.

Part of the Myers-Briggs’ usefulness in the workplace lies in its type-based approach. For practical purposes, it’s easier for people to think in terms of types of personalities rather than in terms of traits on a continuum. However, for scientific understanding, not only do types badly misrepresent the nature of personality, but the characteristics measured by the Myers-Briggs don’t easily map onto the basic personality traits that have been uncovered by personality research. Although it’s a practical tool, personality researchers rarely use the Myers-Briggs Type Indicator.

Common Questions About The Five Major Personality Types

Q: What personality types are considered the five major types?

The five major personality types are conceived to be Conscientiousness, Extroversion, Openness, Agreeableness, and Neuroticism.

Q: Does “big” personality exist?

According to the theory, “big” personality is merely outgoing and somewhat extroverted. Big personality people speak loudly, with conviction, and tend to show confidence.

Q: What does neurotic mean?

Neurotic is generally referred to as neuroticism and defined as an anxious or negative state of mind internalized by the person.

Q: Is the Big 5 personality test considered an accurate measure of one’s personality?

The Big Five test is largely considered the most accurate as it allows for grey areas and soft edges, which, when dealing with complex issues, is key.

This article was updated on July 30, 2020

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