What are INTJ subtypes? The psychological subtypes were originally introduced by Viktor Gulenko, but Dr. Dario Nardi expanded upon the framework in his latest released book Decode Your Personality (2024). The four subtypes are INTJ-D (dominant), INTJ-C (creative), INTJ-N (normalizing), and INTJ-H (harmonizing) Viktor Gulenko's subtype theory explains why "you will see