Trait psychology rests on the idea that people differ from one another in terms of where they stand on a set of basic trait dimensions that persist over time and across situations
Critics of the trait concept argue that people do not act consistently from one situation to the next and that people are very influenced by situational forces
Statistical techniques were used to determine whether a small number of dimensions might underlie all of the thousands of words we use to describe people
There are different ways of being extraverted or conscientious, showing the value in considering lower-level units of personality that are more specific than the Big Five traits