The HIP Metaphor synthesizes complementary research views on the primary brain functions as a biocomputer model of human behavior. The diagram represents personal style in terms of planning versus vision ways of preparing for the future, analysis versus insight ways of solving problems and control versus sharing ways of approaching work.
The six modes are metaphorically associated with the human brain in terms of neurological research on the triune brain by Paul MacLean, the bilateral brain by Joseph Bogan and the frontal brain by Aleksandr Luria. This model blends the findings of all three research perspectives into a broad physiological basis for the HIP Metaphor of personal style.
Three levels of MacLean's triune brain are reptilian (control), limbic (sharing) and neocortex. The left (planning and analysis) and right (vision and insight) hemispheres of Bogan's research are separated by the dashed line down the middle of the neocortex. Finally the Luria research emphasis divides the neocortex horizontally into frontal (planning and vision) and posterior (analysis and insight) halves.
For more perspective on the biocomputer model used as the theoretical basis for the PSI, refer to the "Elaborating the HIP Metaphor" section in Assessing PSI Styles (282K PDF). This paper goes on to describe the statistical development of the original Personal Style Inventory.