Why Your Personality Is a Tool, Not a Cage

In this interview, personality psychologist Will Fleeson discusses his extensive career and his motivation to use scientific research as a tool for long-term social improvement. He explains his development of Whole Trait Theory, which reconciles the historical debate over whether personality is defined by internal structures or observable actions. This framework suggests that traits are inherently dynamic, as individuals constantly adjust their behaviors to align with specific goals and situational demands. Fleeson emphasizes that while people exhibit significant moment-to-moment variability, there remains a foundation of stability over time. Ultimately, he encourages aspiring academics to achieve meaningful contributions by maintaining intellectual autonomy and pursuing their own unique research interests.

You can watch the full video interview on #ISSIDINSIGHTS YouTube podcast here: https://youtu.be/E756U-o1PEw

We are a species of taxonomists, possessed by a relentless urge to categorize the fluid complexity of the human spirit into neat, static boxes. We reach for labels like "introvert" or "extrovert," or the four-letter shorthand of the Myers-Briggs, as if they were genetic sentences rather than mere observations. We treat these categories as permanent mailing addresses for our souls, using them to excuse our silence in boardrooms or our exhaustion at social gatherings. We assume that beneath the shifting tides of our daily lives, there is a "true self" that is frozen, immutable, and fixed.

Yet, for Dr. Will Fleeson, a professor of psychology at Wake Forest University, this deterministic view of personality is not merely a scientific error; it is a missed opportunity for human progress. Fleeson’s entry into the halls of academia was propelled by a profound moral inquiry: how might we find a permanent solution to the persistent problems of human cruelty and exploitation? While he admired the immediate, vital work of organizations like Doctors Without Borders or the strategic interventions of political action groups and NGOs, he feared their impact was transient. To Fleeson, such efforts were akin to treating symptoms while the underlying pathology, the human drive to exploit, remained unaddressed. He suspected that the answer lay in the mechanics of personality. If we could decode the "why" behind human behavior, the internal causes that govern how we treat one another, we might foster a more compassionate world from the inside out.

At the heart of Fleeson’s research lies a compelling paradox that challenges our fundamental understanding of identity:

If personality is supposed to be stable, why do we act so radically different from one hour to the next?

The Civil War of the Soul: The Whole Trait Revolution

For much of the twentieth century, personality psychology was embroiled in a conceptual civil war. On one side stood the behavioral camp, arguing that a trait is simply a description of how you act, a statistical summary of outward conduct. On the other side were the essentialists, who insisted that a trait is the internal structure, the biological or psychological essence, that causes behavior. This wasn't merely an academic spat; the stakes involved the very nature of human agency. If personality is just behavior, it lacks a core; if it is just an internal essence, we are merely puppets of our biology.

In collaboration with his colleague Aronda Jaikramma and other key researchers, Fleeson developed Whole Trait Theory to broker a peace between these warring factions. He realized that a trait is not an "either/or" proposition but a "both/and" system. In Fleeson’s view, personality is the unification of the internal cause and the behavioral manifestation. As he describes it, a trait is "the whole of those two things working together." This shift transforms personality from a static label into a dynamic, integrated system—a move that rescues the concept of agency by acknowledging that while we have internal predispositions, they are part of a larger, active process of living.

The Illusion of the Fixed Type

The most startling revelation of Fleeson’s work is that our self-applied labels are often statistical illusions. Through intensive moment-to-moment monitoring, Fleeson discovered that "extroverts" spend a significant portion of their day acting like "introverts," and vice-versa. In fact, the data suggests that most of us spend the majority of our time neither at the extremes of talkativeness nor in the depths of withdrawal, but rather somewhere in the middle. We are far more variable than we care to admit.

Consider the theatre of the university lecture hall. A student may sit in the audience, quiet, passive, and observant, the very picture of introversion. Meanwhile, the professor stands at the podium, assertive, active, and talkative, a classic extrovert. Yet, as Fleeson points out, the irony is often hidden: the professor may be a "secret" introvert performing a role, while the student is a "secret" extrovert currently constrained by the environment. Both individuals are manifesting behaviors that contradict their "official" personality scores. This variability is not a sign of inauthenticity; rather, it suggests a profound freedom. We are naturally designed to traverse the entire spectrum of human behavior as our circumstances and purposes require.

Personality as a Purposive Toolkit

If our behavior shifts so dramatically throughout the day, we must ask: is this change merely random chaos? Fleeson argues the opposite. Adopting a social-cognitive perspective, he posits that personality expression is "purposive and agentic." We are not simply reacting to stimuli; we are using our traits as tools to achieve specific goals.

We act with introverted restraint in a lecture because our goal is to absorb information, and listening is the most effective means to that end. We adopt an extroverted mantle when leading a meeting because our goal is to convey information and influence others. In this light, our dispositional manifestations are a toolkit we employ to navigate the world. This is an inherently empowering framework. If the version of your personality you express is a product of your goals and your beliefs about how to achieve them, then you are not a prisoner of your type. By shifting your objectives or your beliefs about what is effective, you can effectively change how your personality shows up in the world.

The Moral North Star

This bridge between internal mechanics and external action brings us back to Fleeson’s original "north star": the reduction of human cruelty. By viewing morality, compassion, and generosity as traits with internal causes, Fleeson believes we can study them with the same rigor we apply to conscientiousness or openness.

He is deeply interested in why some individuals prioritize the well-being of others as a central goal while others do not. By uncovering the "internal nature" of these moral traits, Fleeson’s research seeks to identify the cognitive and motivational levers that foster goodness. If we understand the internal causes of compassion, we gain a map for how to cultivate it, moving closer to that "permanent solution" to exploitation he envisioned at the start of his career.

The Persistence of the "Follow Your Nose" Rule

Fleeson’s own journey serves as a testament to the very agency his theory describes. For fifteen years, he faced a wall of academic resistance. When he entered graduate school in 1987, the prevailing winds were hostile to the idea of stable traits; his advisor flatly told him, "There will never be a Big Five measure in any study in my lab." Later, during a long postdoc in the mid-90s, a German advisor dismissed his interest in moment-to-moment variability, claiming "no one will find that interesting."

It wasn't until Fleeson became an assistant professor at Wake Forest in 1996 that he was finally free to pursue the research that would eventually define his career.

He succeeded by "following his nose" and prioritizing his own curiosity over the dictates of academic trends.

He observed that when he tried to please others, the quality of his work diminished. When he focused on what he found meaningful, he produced his most significant contributions to the field.

The Paradox of the Human Spirit

The work of Will Fleeson reveals a beautiful and necessary paradox: human beings are remarkably stable over years, yet remarkably flexible from moment to moment. We are not "finished" products or rigid archetypes; we are change-oriented systems capable of immense adaptation.

Seeing personality as a dynamic tool rather than a fixed box allows for a life of intentional growth. It suggests that while we all have a "home base" a statistical average of who we tend to be, we are capable of inhabiting any part of the human experience if our goals demand it. We are the architects of our own expression.

If your personality is, at its core, a reflection of your goals and your beliefs about the world, it invites a vital question for self-reflection: What version of yourself would you choose to express tomorrow?