The Myers Briggs Temperament Indicator and the iStar share deep roots. Both self-assessment tools are informed, in spirit and design, by an ancient but still vital current of thought and practice. It’s called “the four-fold model of personality” and was first developed 5000 years ago. This model correlates the elements with corresponding human character trait: Fire – Choleric, Air – Sanguine, Water – Melancholic, and Earth – Phlegmatic. This is why an MBTI Report and an iStar Report offer comparable insights.