Personality is the reason you like some people but not others. It is why you prefer noisy parties to translated novels. It is a predictor, some people believe, of your relationship satisfaction and even your waistline. Personality, as defined by the American Psychological Association, refers to “individual differences in characteristic patterns of thinking, feeling, and behaving.” To describe these differences, countless psychologists have come up with innumerable personality scales and measurements. However, over time, consensus formed with the many bespectacled researchers finally reaching common ground in the 1980s.

While each of us has a unique personality, psychologists unanimously say, there are five basic dimensions that can be used to characterize a person — and that do not overlap.

The Big Five, as they are known, are openness, conscientiousness, extraversion, agreeableness, and neuroticism (OCEAN). More precisely, personality psychologists see each of us as landing somewhere along the continuum stretching between five sets of opposing qualities: extraversion and introversion; emotional stability and neuroticism; conscientiousness and impulsivity; agreeableness and hostility; and openmindedness and closemindedness.

Naturally, each of these traits is linked to other what might be called co-dependent characteristics. As measured by a Big Five test, then, openness would include adventurousness, imagination, curiosity, and emotionality, while extroversion comprises personal energy and the tendency to seek stimulation. Similarly, conscientiousness merges with self-discipline, dutifulness, and an orientation toward achievement, while agreeableness, according to the test, necessarily involves compassion. Finally, neuroticism contains the seeds of anxiety, anger, and depression.

Big Five Traits
OCEAN: openness, conscientiousness, extraversion, agreeableness, and neuroticism Photo courtesy of Shutterstock.

When you take a test for the Big Five, your personality is measured as five separate percentile scores. If you get a score of “60” in the conscientiousness category, that would mean your sense of responsibility and orderliness was higher than 60 percent of those who took the test. As you age, it is said, your score will change since over the lifetime, it is common for scores on agreeableness and conscientiousness to rise, while scores on extroversion, neuroticism, and openness decrease.

It is important to remember that the Big Five does not represent a particular theory of personality. Instead, psychologists see these core traits as natural language terms most people commonly use to describe themselves and others. In other words, the Big Five is simply a framework or the least common denominator of personality — a necessary shorthand understood by one and all.

Take the test here.

Health and the Big Five

Most people believe your personality influences your life, while personality scientists might say it decides your fate. To their way of thinking, personality determines not only your wealth but also your health. Neuroticism, which by definition is a negative trait, is most naturally linked with poor health.

“Individuals who score high on neuroticism are more likely to experience a variety of problems, including negative moods (anxiety, fear, depression, irritability) and physical symptoms,” one study found, while another found evidence that neurotic people are likely to be especially affected by negative life events, and to have bad moods linger. Going even further, quite a few studies have supported conclusions that the higher you score on neuroticism, the higher your risk of mortality.

As one study explains it, people high in neuroticism tend to smoke and drink more and since there’s no doubt these behaviors can damage your health and shave years off your life expectancy, it is only natural that neuroticism, then, might raise your risk of mortality. By comparison, conscientiousness is generally related to not smoking and drinking, while openness (and that pesky trait of wanting stimulation) means you are likely to drink and smoke yet you also tend to exercise.

In the end, researchers have discovered it is your behavior (mediated by your personality) that impacts your health. It is what you do, and not your intrinsic personality that matters.