The two most common dispositional theories are Allport’s psychology of the individual theory and the trait and factor theory. Allport’s psychology of the individual theory emphasized that people are unique, even though they may share traits in common, and those unique qualities are what should be focused on. “More than any other personality theorist, Gordon Allport emphasized the uniqueness of the individual. He believed that attempts to describe people in terms of general traits rob them of their unique individuality”.
In order to focus on the individuals uniqueness Allport felt that a broad theory is more useful than a narrow one and he would use information from different theorist in his research.
For many years there has been much debate about how many traits actually have an effect on an individual’s personality. In recent years the majority of theorist have come to the conclusion that five is the magic number. Esyneck, McCrae, and Costa have focused their studies on the trait and facto theory and have done much research using standardized tests, clinical observations, and observations from friends and families of the individuals studied.
“Trait and factor theories of personality are based on factor analysis, a procedure that assumes that human traits can be measured by correlational studies”.
Each of these theories have different approaches to explaining an individual’s behavior. Both Allport’s psychology of the individual theory and the trait and factor theory have its own effect on individual personalities. Interpersonal relationships are influenced by each of these theories in its own way as well.