Why INFJ and Door Slam are often discussed as a set

The reason why INFJ and door slam are often discussed as a set is, to put it quite crudely, because it is too convenient as a 'self-narrative that looks like an INFJ' I think.

First of all, the concept of a door slam itself can be explained well with the INFJ's functional structure. It is easy to create a narrative where an INFJ generally reads the other person's patterns long-term with Ni, tries to maintain the relationship with Fe, verifies consistency internally with Ti, and when the limit is reached, cuts off contact with reality in an Se-like manner. In other words, the explanation that "I was patient for a long time," "I gave signs many times," "I decided that the other person wouldn't change," and "That's why it only looks like I cut them off suddenly" fits the INFJ image very well.

However, this is important: not everyone who talks about it is a genuine INFJ.

Rather, on the internet, a door slam is often used as a self-justification narrative that says, "I am not cold-hearted, but a highly evolved human being who has been deeply hurt." This happens not only with INFJs, but also with INFPs, INTJs, ISFJs, ENFJs, and in some cases, it can even be caused by simple avoidant attachment, narcissistic defense, or poor boundary setting. But when you call it an "INFJ door slam," it suddenly becomes mystified.

In short, a simple severance of a relationship looks like a "final judgment based on deep insight" by passing it through the INFJ label.

A door slam by a more genuine INFJ is probably more understated. It is not an emotional outburst of "Okay, it's over!" but rather a process of observing, tolerating, explaining, watching the other person's reaction, and internally withholding judgment many times over a fairly long period. After that, the moment they decide, "This person will not change," "This relationship is destroying me," or "The cost of maintaining this relationship is too high both ethically and practically," it suddenly cools down from the outside. It is not sudden for the person themselves. It just looks sudden from the outside. There is a discrepancy here.

On the other hand, fake-sounding door slam narratives usually go like this.

"Because I'm an INFJ, I endure until my limit"
"I can see through people"
"Once I cut someone off, I never go back"
"If you make me angry, it's over"
"I cut them off because the other person is at fault"

This is quite suspicious. Because, rather than the deep relationship ethics of an INFJ, it is closer to a characterization of "I am a specially sensitive and specially scary existence". It has become a performance of a "saint with darkness" as an internet persona rather than an INFJ.

There are probably three reasons why a door slam is associated with an INFJ.

The first is that INFJs are easily described as a "type that values relationships but looks at people quite calmly on the inside." It is easy to create a composition where they are kind with Fe, see through people with Ni-Ti, and therefore are scary when they finally cut them off.

The second is that INFJs are easily consumed as a rare type, a deep type, or a misunderstood type. A door slam fits that myth perfectly. The character trait of "usually kind, but disappears when truly disappointed" is strong.

The third is that many people who talk about MBTI on the internet are actually seeking a self-narrative rather than an understanding of the type. In other words, the INFJ label is used to explain "why I cut off human relationships." There, a story that beautifies one's wounded self becomes more important than type theory.

Therefore, to be quite strict, more than half of INFJ door slam narratives may be "self-justification literature for relationship severance" rather than INFJ theory.

However, that does not mean that a genuine INFJ-like severance does not exist. In fact, it does. The characteristics are not getting loudly angry. Not attacking the other person. Not over-advertising to those around them that "I am a victim." Observing for a very long time before cutting them off. And after cutting them off, rather than continuing to hate the other person, it becomes a process of "no longer including that person in the structure of my life."

In other words, a door slam close to the real thing is not an emotional explosion, but closer to an expulsion from a relationship.

Conversely, fake-sounding ones are a threat like, "I'm an INFJ, so I'm scary if I cut you off, okay?" This is not a door slam, but just relationship manipulation. Or, it is the fixation of a victim position that says, "I endured this much, so it's natural that I cut them off." This is also better seen as immature Fe, wounded Fi, or narcissistic defense rather than INFJ functional theory.

In conclusion, the reason why INFJ and door slam are discussed as a set is because the image of an INFJ being "kind, but ultimately quietly giving up on someone" is very compatible with self-presentation on the internet.

However, I think a genuine INFJ-like door slam is more silent, more calm, and more business-like.
It is not "I am scary if you make me angry," but
a judgment that "this relationship is no longer a subject for maintenance."

Therefore, when you see an INFJ door slam narrative, it is good to distinguish it like this.

Authentic-leaning INFJ door slam
"Long-term observation, efforts to maintain the relationship, quiet withdrawal, exhaustion from explaining, loss of interest in reconnecting"

Fake/self-dramatizing-leaning door slam
"I see through people, I am scary, I endured until my limit, it is the fault of the person who was cut off, it cannot be helped because I am an INFJ"

I think this is the difference.
The INFJ door slam is not inherently a "special move of anger," but rather a final structural judgment regarding the relationship I believe.