1.Cardinal Trait- This trait dominates and shapes a person's behavior. These are ruling passions/obsessions, such as a need for money, fame etc.
2.Central Trait-This is a general characteristic found in some degree in every person. It is the general building blocks that shape most of our behavior. An example being honesty.
3.Secondary Trait- These are characteristics seen only in certain circumstances (such as certain likes and dislikes that only a close friend would know) they must be included to provide a complete picture of human complexity.
He also hypothesized the idea that people have internal and external forces called Genotypes and Phenotypes.
Genotypes- are internal forces that relate to how a person retains information and uses it to interact with the external world, like your genetics.
Phenotypes- external forces that relate to the way and individual accepts their surroundings and how others influence their behavior.
Other interesting things…
He was the president of American Psychological Association in 1939.
He was also the president of the Society for the Psychological Study of Social Issues in 1944