Ever since Hippocrates and the ancient Greeks, people have been trying to find a way to classify personality into types. The ancients had the four temperaments, while current culture has popularized assessments like the Myers-Briggs Type Indicator and the DISC personality test.
The idea of a personality "type" is also widespread. Many people associate a "Type A" personality with a more organized, rigid, competitive, and anxious person, while a type B personality signals flexibility, creativity, and relaxation. Yet there’s little empirical support for the idea. In fact, it didn’t even emerge from psychology—two cardiologists created the concept as a way to understand the connection between stressed patients and the likelihood of developing heart disease and high blood pressure.
Psychologists who study personality believe such typologies generally are too simplistic to account for the many ways people differ in personality. Instead, there is broad scientific consensus that there are five major traits: openness, conscientiousness, extraversion, agreeableness, and neuroticism.
These traits generally remain stable across one's lifetime. They can also predict behavior in certain situations or correlate with life outcomes. High conscientiousness, for example, is associated with higher lifetime earnings.
Each of these key traits contributes to one's personality and is independent of the others. They combine in countless ways to create individuality.