Looking at the cognitive functions of each type, one can find the other identities or types with similar cognitive functions but different arrangments. For example, the functions for INFJ are:
While those for ESTP are backwards:
So the shadow identity of an INFJ would be ESTP, which is almost an extroverted version of INFJ. Similarly, that for ENFJ would be ISTP, and vice versa. Though ENFJ also shares cognitive functions with INFJ, the closest link for INFJ would be ESTP.
Shadow identities occur when people begin to fully develop their functions, and in many cases, the people act similar to their shadow identities when socially interacting. The shadow identities of the types:
ISTJ - ENFP
ISFJ - ENTP
ESTJ - INFP
ESFJ - INTP
ISTP - ENFJ
ISFP - ENTJ
ESTP - INFJ
ESFP - INTJ
Please let me know your opinions or if you have any questions. Thank you.