The T in personality tests stands for turbulent. It is a variant of the Identity aspect that shapes a personality type. There are five such aspects that are given a letter each to represent the variant. Your personality type can be Introverted (I) or Extraverted (E), Intuitive (N) or Sensing (S), Feeling (F) or Thinking (T), Judging (J) or Perceiving (P). Some tests attach another letter after these four. That one can be a T for Turbulent or A for Assertive. Being Turbulent means that you score high on neuroticism and tend to be self-conscious and critical.