Personality Described

Note: This essay is reproduced from the original on the Psychology Today website published December 9, 2013 by John D. Mayer, Ph.D. in The Personality Analyst

When we ask, “Who am I?” or “Who are you?” we’re asking questions about the overall system that governs our mental life: personality. Our personality contains our identity and motives, our emotions and skills, and clues to our future. It’s our own individual edition of human nature.

Psychologists define personality as a system—an organization of interrelated parts. The parts themselves are our areas of major psychological functions: our motives and emotions, thoughts and knowledge, action-planning, and our sense of self and self-control.

A common misconception about personality psychology is that its chief aim is the study of individual differences—how one person differs from another. That’s true to a point, but the usual process in personality psychology is to look for universal features of human nature, and then see how people vary on those. For example, first, we identify extraversion (sociability, liveliness) as something we all share in common, then, we examine how people differ in their extraversion: for example, why some people are high in extraversion and others are low (introverted) and what that means to a person’s life.

Personality emerges and adapts in part by molding the major parts of our mental life—our motives, feelings, thoughts and self-control—into a functioning system. Because none of us possesses the same exact qualities, our personality must organize our particular psychological pieces in a way that is adapted to our specific environment with its unique opportunities and challenges.

A fundamental assumption of systems theory is that each piece of our psychological puzzle has advantages and disadvantages for us. So, what one observer might view as courage, another might see as recklessness.

Daniel Nettle, an evolutionary psychologist at Newcastle University (in northeast England) has pointed out the two sides to a few of the key traits that describe us, including extraversion, openness and agreeableness (see this post for more about these traits). For example, if we are highly extraverted, we have an advantage in terms of forming social allies, mating successfully, and exploring the environment around us in beneficial ways. Those same traits may present disadvantages if our ease at social relationships threatens the stability of our family or if our lively explorations lead us to take unwise physical risks. In another example from Nettle, if we are high on the trait of openness—which includes being imaginative, thinking independently, and entertaining unusual ideas—we are more likely to be creative. We’ll engage in activities such as playing a musical instrument that potentially enhances our attractiveness to others. On the other hand, our openness may lead us to develop unusual and maladaptive beliefs, such as placing undue stock in superstitions, coincidences, and unsupported beliefs.

In a third example, Nettle points out that being agreeable leads us to harmonious interpersonal relationships, and can make us a valued member of a coalition, but that it also exposes us to the social cheating of others, and a failure to maximize selfish advantages.

So personality is an evolving, adaptive system, that puts together the many pieces of our selves into a functioning, surviving thriving person. We do that somewhat naturally. Through trial and error, we are likely to discover that we do certain things more easily and better than others—we may play the guitar more gracefully than we throw a ball, and so we find it more rewarding to develop our musical talents than to play on a ball team.

Over time, we nurture the skills we like to use and are good at, which strengthens them. And, similarly, we find the positive aspects of our preferences—the solitude we like as an introvert allows us to appreciate intimate one-on-one talks with others and the time to think; or, alternatively, the social companionship we crave as an extravert provides for our entertainment and large measures of social support over time. In these ways, our skills become stronger and we gravitate to situations and contexts that we prefer because they reveal our better selves to others. By doing things that we can based on our abilities and by choosing what we like according to our preferences, we strengthen the capabilities we express in the world.


Daniel Nettle has pointed out… see Nettle, D. (2006). The evolution of personality variation in humans and other animals. American Psychologist, 61, 622-631.

Copyright © 2013 by John D. Mayer