The instinctual variants of a personality indicate which of the three instincts are priorities for them. These instincts include self-protective (sp), sexual (sx), and social (so). The primary instinct is the most imbibed nature and is listed first.  The secondary instinct is still a little unfamiliar despite its importance. It is listed second after the slash. The third instinct is called the blind spot and is uncharted territory for the person. It is not listed when describing a personality.