The Holland Codes or the Holland Occupational Themes (RIASEC) refers to a theory of careers and vocational choice (based upon personality types) that was initially developed by American psychologist John L. Holland.
The US Department of Labor ETA has been using an updated and expanded version of the RIASEC model in the “Interests” section of its free online database, The Occupational Information Network (O*NET), since its inception during the late 1990s.
“Holland made a career out of studying the world of work, pioneering the theory that if people were aware of their personality type or combination of types – realistic, investigative, artistic, social, enterprising or conventional – then they would be happier workers.”
Holland’s theories of vocational choice, The Holland Occupational Themes, “now pervades career counselling research and practice.” Its origins “can be traced to an article in the Journal of Applied Psychology in 1958 and a subsequent article in 1959 that set out his theory of vocational choices [….] The basic premise was that one’s occupational preferences were in a sense a veiled expression of underlying character.” The 1959 article in particular (“A Theory of Vocational Choice,” published in the Journal of Counseling Psychology) is considered the first major introduction of Holland’s “theory of vocational personalities and work environments.”
Holland originally labeled his six types as “motoric, intellectual, aesthetic, supportive, persuasive, and conforming.” He later developed and changed them to: Realistic (Doers), Investigative (Thinkers), Artistic (Creators), Social (Helpers), Enterprising (Persuaders), and Conventional (Organizers).” Professor John Johnson of Penn State suggested that an alternative way of categorizing the six types would be through ancient social roles: “hunters (Realistic), shamans (Investigative), artisans (Artistic), healers (Social), leaders (Enterprising), and lorekeepers (Conventional).”
According to the Committee on Scientific Awards, Holland’s “research shows that personalities seek out and flourish in career environments they fit and that jobs and career environments are classifiable by the personalities that flourish in them.”Holland also wrote of his theory that “the choice of a vocation is an expression of personality.” Furthermore, while Holland suggests that people can be “categorized as one of six types,” he also argues that “a six-category scheme built on the assumption that there are only six kinds of people in the world is unacceptable on the strength of common sense alone. But a six category scheme that allows a simple ordering of a person’s resemblance to each of the six models provides the possibility of 720 different personality patterns.”