Understanding personality type: What do type dynamics tell us about life stages and stress reactions?

A beginner's guide to type dynamics

The two central letters of a type denote the functions—for example, S and T are the functions of the type ESTJ. One of these functions is dominant (in bold), and operates in either the extravert or the introvert mode, depending on that type's preference,1 and the other letter denotes the second, auxiliary function. If the dominant function is extraverted, the auxiliary function will be introverted, and vice versa, thus providing balance and support for the dominant. In the type ESTJ, the dominant function is extraverted T, whereas the auxiliary is introverted S. There is then a tertiary function, which is the opposite of the auxiliary function (so if the auxiliary function is sensing, the tertiary function will be intuition), and finally, there is an inferior function, which is the opposite of the dominant function (see box 1 for example).