Personality traits reflect people's characteristic patterns of thoughts, feelings, and behaviors. Personality traits imply consistency and stability—someone who scores high on a specific trait like Extraversion is expected to be sociable in different situations and over time.

Raymond Bernard Cattell (1905-1998) was one of the most important theorists in the area of personality. He is listed among the top greatest 20 psychologists of the twentieth century. In Cattell’s view, personality is the manner in which human beings behave in a certain situation. From this perspective, it is possible to infer personality traits based on a set of behaviors and, reciprocally, it is possible to predict how a person would behave in a certain situation by having information about their personality traits. In the 1940s, Cattell started a significant research that sought to identity the basic global factors of personality in a multivariate approach of traits or factors (Walter, 1995). Based on the famous list of adjectives of Allport’s, Cattell reorganized it into 171 personality descriptors, which were used to describe the personality in empirical studies involving factor analysis (Cattell, 1943).
Raymond Cattell’s personality research was based on his strong background in the physical sciences; born in 1905, he witnessed the first-hand awe-inspiring results of science, from electricity and telephones to automobiles, airplanes, and medicine. He wanted to apply these scientific methods to the uncharted domain of human personality with the goal of discovering the basic elements of personality (much as the basic elements of the physical world were discovered and organized into the periodic table). He believed that human characteristics such as creativity, authoritarianism, altruism, or leadership skills could be predicted from these fundamental personality traits (much as water was a weighted combination of the elements of hydrogen and oxygen). For psychology to advance as a science, he felt it also needed basic measurement techniques for personality. Thus, through factor analysis – the powerful new tool for identifying underlying dimensions behind complex phenomena – Cattell believed the basic dimensions of personality could be discovered and then measured. The personality trait test can be used as a career evaluation tool, for couples counseling and personality assessment.  16 PF is used by psychologists and counselors to provide job occupations that best fit the individuals’ characteristics.  Also, 16PF can identify such problems as anxiety, behavioral adjustment, academic, emotional, and social.