John L.Holland

John L. Holland is an American psychologist who spent much of his career at Johns Hopkins University. He received his B.S. from the University of Omaha and Ph.D. from the University of Minnesota.

Holland is the creator of the best known and widely researched theory of career choice. It includes six personality types that are often abbreviated as RIASEC and are used to create the well known Holland Codes.

Holland Codes are personality types created by psychologist John L. Holland. As part of his theory of career choice, Holland's (1985) Vocational Preference Inventory (VPI) is the name of the test he created to measure an individual's type and match it with a list of career choices that would theoretically be good for that individual.

Holland mapped these types into a hexagon which he then broke down into the RIASEC job environments:

• Realistic - practical, physical, hands-on, tool-oriented
• Investigative - analytical, intellectual, scientific, explorative
• Artistic - creative, original, independent, chaotic
• Social - cooperative, supporting, helping, healing/nurturing
• Enterprising - competitive environments, leadership, persuading
• Conventional - detail-oriented, organizing, clerical

Holland argues that 2-3 types dominate in each person.