The Big Five Personality Trait Theory, Explained

When people talk about “the Big Five theory,” they usually blend two different things. One is the Five-Factor Model, a classification: it says that personality differences between people are well summarized by five broad dimensions. The other is the set of theories that try to explain why those five dimensions exist, where they come from, and how they turn into behavior.

The distinction matters because one of the most repeated criticisms of the Big Five is that it describes without explaining. For decades that was true. Today there are at least two serious explanatory theories built on top of it, and this article focuses on them.

First, the classification: where the five factors come from

The model was born from language. The lexical hypothesis holds that the differences that matter most in social life end up with names in everyday vocabulary. In 1936 Allport and Odbert compiled about 18,000 terms from an English dictionary; Raymond Cattell reduced them to a few dozen variables, and later factor analyses by Tupes and Christal, Norman, and Goldberg found the same five-cluster structure again and again.

Those clusters are the five traits that the acronym OCEAN calls to mind today:

• Openness to experience: the breadth and complexity of mental life, and interest in ideas, art, and novelty.
• Conscientiousness: organization, persistence, and impulse control in the service of goals.
• Extraversion: social energy, assertiveness, and a tendency to feel positive emotions.
• Agreeableness: cooperation, trust, and consideration toward others.
• Neuroticism: a tendency to experience negative emotions such as anxiety, sadness, or irritation.

Up to this point, everything is description. Factor analysis tells us which adjectives go together, but not why they go together.

McCrae and Costa’s Five-Factor Theory

The first systematic attempt to turn the classification into a theory came from Robert McCrae and Paul Costa, the authors of the NEO-PI-R, starting in 1996. Their Five-Factor Theory (FFT) organizes personality into several connected components:

• Basic tendencies: the five traits, understood as biologically based dispositions. They are not observed directly; they are inferred.
• Characteristic adaptations: the habits, attitudes, skills, roles, and relationships each person develops as their traits meet a particular environment.
• Self-concept: the idea each person has of themselves, which the theory treats as one more adaptation.
• Objective biography: what the person does and what happens to them over a lifetime.
• External influences: culture, family, circumstances.

An example helps show the difference between the first two layers. Two people with the same high extraversion can express it in very different ways: one becomes a sales rep in Chicago and organizes the dinners on her block; the other, raised in a setting that prizes discretion, channels the same energy into a hiking club. The trait would be the same; the adaptations would not.

The FFT’s strongest and most debated claim is that traits are endogenous: according to McCrae and Costa, culture and experience shape the adaptations but barely touch the basic tendencies, which would mature following a largely biological program.

What the evidence supports and what it disputes

Two solid findings work in the FFT’s favor. The average heritability of traits is around 40% according to the meta-analysis by Vukasović and Bratko (2015), with more than 100,000 participants, and the five-factor structure shows up in samples from dozens of cultures.

Against it, longitudinal studies show that traits change more than the theory predicts. The meta-analysis by Roberts, Walton, and Viechtbauer (2006), covering 92 samples, found that conscientiousness and emotional stability increase mainly between ages 20 and 40, and other authors attribute part of that maturation to adult roles (work, partnership). A review of 207 intervention studies (Roberts et al., 2017) found average changes of d = 0.37 over about 24 weeks, mostly in emotional stability. These are modest effects, but hard to reconcile with a strict version of traits that are immune to the environment.

The meta-traits: Stability and Plasticity

A second finding any theory has to explain is that the five factors are not independent. They correlate with each other systematically.

John Digman (1997) reanalyzed 14 datasets and showed that they group into two higher-order factors, which he simply called alpha and beta. Colin DeYoung (2006) confirmed the structure in a sample with multiple informants, which rules out a mere self-report bias, and gave them the names used today:

• Stability (alpha): agreeableness, conscientiousness, and low neuroticism. It captures the capacity to keep emotional and social functioning organized, without impulses or disturbances knocking it off course.
• Plasticity (beta): extraversion and openness. It captures the tendency to explore and engage with the new, both in the social world and in the world of ideas.

Plasticity here does not mean brain plasticity or learning ability: it is the name of a meta-trait, a higher-order statistical dimension.

DeYoung’s Cybernetic Big Five Theory

The most ambitious explanatory proposal of recent years is DeYoung’s Cybernetic Big Five Theory (2015). It starts from cybernetics, the science of systems that pursue goals and correct themselves using the information they receive, like a thermostat or an autopilot.

Its central idea: people are goal-pursuing systems, and traits reflect differences in the parameters of the evolved mechanisms that run that cycle. Each meta-trait has a function:

• Stability protects goal pursuit from distractions and impulses. DeYoung tentatively links it to serotonergic function.
• Plasticity drives exploration and the creation of new goals and interpretations. He links it to dopamine.

Within that framework, neuroticism would be the system’s sensitivity to threats and punishments; extraversion, its sensitivity to reward; openness, cognitive exploration; conscientiousness, the prioritizing of distant goals over immediate impulses; and agreeableness, the coordination of one’s goals with those of other people.

Like the FFT, CB5T also distinguishes between traits and characteristic adaptations, but it defines the latter as the specific goals, interpretations, and strategies each person learns. And it goes a step further: it understands psychopathology as a persistent failure of the system to move toward its goals, which connects the Big Five with clinical research.

What remains open

Neither theory is settled. CB5T’s neurobiological hypotheses are largely research programs, not established results. The FFT has been qualified in light of the data on change. And the five-factor structure itself has rivals, such as the six-factor HEXACO model, which we cover in the criticisms of the Big Five.

What does seem solid is the foundation both are built on: five continuous dimensions, organized into two meta-traits, with a moderate heritable component and real room for change across the lifespan.

You can see where you land on these five dimensions with our Big Five test.

Sources

• Allport, G. W. and Odbert, H. S. (1936). Trait-names: A psycho-lexical study. Psychological Monographs, 47(1), i-171.
• Digman, J. M. (1997). Higher-order factors of the Big Five. Journal of Personality and Social Psychology, 73(6), 1246-1256.
• DeYoung, C. G. (2006). Higher-order factors of the Big Five in a multi-informant sample. Journal of Personality and Social Psychology, 91(6), 1138-1151.
• DeYoung, C. G. (2015). Cybernetic Big Five Theory. Journal of Research in Personality, 56, 33-58.
• McCrae, R. R. and Costa, P. T. (2008). The five-factor theory of personality. In O. P. John, R. W. Robins and L. A. Pervin (Eds.), Handbook of personality: Theory and research (3rd ed., pp. 159-181). Guilford Press.
• Roberts, B. W., Walton, K. E. and Viechtbauer, W. (2006). Patterns of mean-level change in personality traits across the life course: A meta-analysis of longitudinal studies. Psychological Bulletin, 132(1), 1-25.
• Roberts, B. W., Luo, J., Briley, D. A., Chow, P. I., Su, R. and Hill, P. L. (2017). A systematic review of personality trait change through intervention. Psychological Bulletin, 143(2), 117-141. doi:10.1037/bul0000088
• Vukasović, T. and Bratko, D. (2015). Heritability of personality: A meta-analysis of behavior genetic studies. Psychological Bulletin, 141(4), 769-785. doi:10.1037/bul0000017