While there have been many different theories of personality, many psychologists today believe that personality is made of if five broad dimensions, a notion often referred to as the big five theory of personality or the five-factor model. The big five personality traits the theory describes are Openness, Conscientiousness, Extroversion, Agreeableness, and Neuroticism (OCEAN).
There are many different theories of personality and the trait theories attempt to describe personality as composed of a number of different traits which them influence how people behave. Just how many traits are there? Theorists have proposed a variety of numbers to capture all of the traits that make up the human experience.
An early psychologist named Gordon Allport, the man often credited with helping to popularize psychology in America, examined dictionary terms related to personality traits and concluded that there were more than 4,000. Later, the psychologist Raymond Cattell utilized a statistical technique known as factor analysis to whittle that list down to just 16.
Hans Eysenck shortened that list to a mere three broad dimensions, but later researchers revised and expanded this to include five dimensions of personality. Rather than focusing on individual terms that describe each and every aspect of a trait, this theory aims to instead focus on the broader aspects of human personality.