According to Jung, behavior was motivated by a kind of continuous life "force" that included overall motivation and caused people to aim for wholeness and creativity, not simply sexual fulfillment.

Holland’s codes appear on a wheel with the acronym “RIASEC”—realistic, investigative, artistic, social, enterprising, and conventional. Traits next to one another on the wheel are most likely to appear together in a personality code. Traits across from each other on the wheel, such as artistic and conventional, are much less likely to appear on a profile together.

A "cardinal trait" dominates a person's personality to the point that others almost always identify them with the trait. "Central traits" are also a significant part of a personality, but not as dominant as cardinal traits. "Secondary traits" tend to come out only in certain situations and are more flexible. Note that "primary trait" is not a term used in Allport's theory. 

The Big 5 are dimensions of personality that spell out the acronym "OCEAN." They include the following: "openness to experience," "conscientiousness," extroversion/introversion, "agreeableness," and "neuroticism." "Locus of control" is not one of the Big 5 personality traits. It is a theory developed by Julian Rotter about how people perceive control over events in their lives. Locus of control can be divided into internal (i.e. people believe they have great control over their lives) and external (i.e. people feel they have little control over their lives). 

Defense mechanisms function to prevent the unconscious urges of the id (i.e. the part of the mind that relies on the pleasure principle) from entering into awareness. Reaction formation involves saying or doing the opposite of what you actually feel (i.e. "being loving and warm toward a person you are angry with"). Feeling anger toward a safer person or object is an example of displacement. Forcing uncomfortable feelings like anger out of your mind is an example of repression. Distancing yourself from feelings is an example of intellectualization. Last, attributing your own feelings to someone else is projection.

There are numerous trait theorists with various beliefs—traits are both nature and nurture influenced, traits are hierarchical and traits have no influence on each other, there are five key traits and there are dozens. The following core key factors are tenants of all trait personality theories: traits are relatively stable over time, traits influence behavior, and traits are bipolar.

Freud's psychosexual stages of development are as follows: Oral, anal, phallic, latency, and genital. Unresolved conflicts (i.e., fixation) during each stage can lead to different personality characteristics that are maintained through adulthood. Fixation during the oral stage results in excessive dependency, while a fixation in the anal stage can lead to being overly orderly and rigid or overly messy. Libido is the or libidinal energy represents the drive that occurs in psychosexual development, according to Freud.

Unlike other personality theorists, Freud believed that libido was present from birth. He believed that libidinal energy and the drive to reduce libidinal tension were the underlying dynamic forces that accounted for human psychological processes.