The Greek philosopher Hippocrates ascribed four personality types to the effects of varying levels of different bodily fluids (blood, bile, etc.). Long-established caste and other hierarchical social systems describe differences in people based on birth circumstances, such as being an untouchable or having royal blood. In multi-theistic traditions, the gods themselves have distinctly different personalities. Various religious texts describe gifts from gods, many of which are like personality characteristics. The Mesopotamian society provided the 12 signs of the zodiac, which astrologists use to describe personality differences based on the day of birth. Ancient Chinese society described personality types based on the year of birth. The idea of personality types is hardly new. The SDI 2.0, like all modern personality assessments, rests on the conceptual foundation laid by earlier societies and theorists. Let’s rewind the clock a bit and get started. I wanted to commit the facts to writing and hoped that the story would be interesting for anyone who uses the SDI 2.0. I wrote this article because I realized that I was the sole keeper of an “oral history” of the SDI. I use the first person when I narrate my own involvement or add personal observations. I am both the narrator and an actor in this story. Overdone Strengths Portrait – a ranking of non-productive strengths used at work.īut this is not just a story of a product it is a story of people interacting with each other and the social forces of their times.

Strengths Portrait – a ranking of productive strengths used at work.

Conflict Sequence – a personality type when experiencing conflict.

Motivational Value System – a personality type when things are going well.

The SDI 2.0 is now a single assessment that produces four interrelated views of a person: This is the story of the SDI 2.0, so named to reflect its evolution since Porter created it. The more I learned about him, his Relationship Awareness Theory, and the SDI, the more I became convinced that his modesty and desire to help others succeed caused him to become an overlooked figure in psychology. He wanted to help people and was not overly concerned about getting credit for his work. I never had the opportunity to meet Porter, but I do know one word that says a lot about him: Blue (shorthand for his Altruistic-Nurturing Motivational Value System).

I have assumed the mantle of SDI development, and someday that mantle will pass to someone else. That distinction rightly belongs to Elias Porter, or “Port” as his friends called him. Given my role, people often ask if I am the founder or creator. I have been working full-time with the SDI since 1995 and have contributed to its development and utility through research, authorship, and application.

Strength deployment inventory