According to the first trait theorist, Gordon Allport, traits are the unique identifiers that compose our personality. In Allport's Trait Theory, traits are either central, secondary or cardinal.
A cardinal trait is the most dominant of traits and it defines entirely the behavior of a person. Since not one single trait defines a person quite entirely, it is hard to extrapolate a cardinal trait. A famous musician, such as Prince, might find in his daily dynamics with fans and with the people who push him to go higher within the ranks of other musicians the agents that propel his traits. Hence, an artist who is overly cherished, lionized and admired might develop both positive and negative cardinal traits such as eccentricity, histrionic, or narcissistic traits to accentuate their artistic persona.
Central traits are universal traits shared by many people in general. They also shape our behavior. In the case of someone who is well-known, central traits are often developed just like with anyone else. However, as an artist, Prince would have to hide his central traits from his audience to protect his personal space and privacy. Although central traits are universal, a musician with an eccentric personality such as Prince will go overboard to disguise them in order to establish a creative look. The purpose of this is to deflect the image of the "man" from the "artist". Negative central traits might be created by dysfunctional dynamics, lack of trust in the general public (or family) or by external motivators such as money, drugs, alcohol, fame, stress, or pressure. Hence, if Prince was once someone who shared a good central trait, such as honesty, for example, it is not uncommon to see that often fame and popularity change a person from openly kind to reserved and distrusting.
Secondary traits come up under specific circumstances, for instance, in the way we react to things, or in the choices that we make for our behavior when things go our way, or do not go our way. Secondary traits may actually come as a surprise to someone as famous and as eccentric as Prince, because his behavior already tends to opt for surprising and shocking choices in dress, in the way that he talks, moves, and expresses himself. Hence, the cause of secondary traits is also a product of interaction with the environment, our prior knowledge, and our dynamics with others (lest we forget to also include biological factors). As the individual ages, the traits become autonomous, which means that they attach to our everyday behavior. This would have been Prince's case, as his unique traits seem to have transpired onto his personal life, which he also claims to follow similar patterns as his artistic life.