He called such underlying personality characteristics source traits. Using a statistical technique called factor analysis to reduce surface traits to source traits, he developed a list of 16 underlying source traits he considers the basic number necessary to describe an individual personality. A trait profile presents a graph of a person s scores for each trait. Trait profiles can e very helpful for obtaining a picture of an individual personality or for making comparisons between the personalities of two or more persons. Trait-situation interactions .
Traits interact with situations to determine behavior.
Ordinal position . Birth order in family. Have a higher chance of achieving eminence that later-born persons. Have better high school and college grade averages. More become National Merit Scholars, more are medical students or graduate students.