The 6th function is a force to be reckoned with, lurking in the unconscious yet quite powerful. It is the secret weapon of every type. It is actually obvious in its strength and ability if you focus your attention on it, but we do not tend to do this in our day-to-day consciousness. It is the function that is the elephant in the room that you consciously ignore, but it is quite present.
The 6th function is “very strong,” or “4th-Dimensional.” However, since the type does not see its intrinsic worth, it is treated sort of as a joke: it is not taken seriously in itself, and is thus viewed as a means to an end. The end is the purposes of the primary and auxiliary function. For example, an ESFJ is actually aggressive, due to Se, but does not have an aggressive worldview. They value peaceful, relaxing environments, due to Si.
However, the ESFJ will channel their own aggressive energy into being very proactive and energetic about creating a pleasant environment. An Se-valuing ESFP, on the other hand, is not only aggressive, but values an aggressive worldview: a world where people are allowed to be competitive and challenge each other, which is actually their way of growing.
This tendency gives the 6th function makes it private: it is not a way of operating that the type would share with others (the ESFJ would not promote a stressful, competitive environment over a harmony and relaxed one), but will personally use their aggressive energy to accomplish their goals.
There is an advantage to this: other people see how they benefit from your 6th function, and would value you are a result—and furthermore, you do not make a big deal of it. People are very particular about their first function because they are actively promoting its worldview, which can be preachy to others, turning them off. An example would be how the ESFP uses their 6th function Fe effortlessly, creating a fun and festive environment that brings people together, yet does not insist on harmony and that everyone get along. An ESFJ, on the other hand, would not only try to bring people together, but insist on harmony and critique those who do not.
However, since it is not valued, the 6th function can also blow over in a negative state. When this happens, the ESFP can get reactive and dramatic with Fe, and an ESFJ will get very aggressive. Since it is not managed via the conscious, it will find a way to express itself, such as being very critical of others. In Dr. Beebe’s model, the 6th function is the critical parent.
The type will start associating negative states with their 6th function, further devaluing the function. Another reason why the function is unvalued is that the very strong 6th function turns off their tertiary function, otherwise known as the Hidden Agenda. These two functions cannot be on at the same time. The Hidden Agenda is the function that people value so much, they exaggerate their own ability in it (when everyone else clearly sees it is deficient and are annoyed by its puerile expression). The 6th function, on the other hand, is the powerful function that the type devalues (when everyone else clearly sees and respects its strength).
The 6th function can even be in certain ways more powerful than the dominant. This is because it exists as an unconscious force not controlled and consciously managed by the psyche, as is the dominant. It can really rear its head (both in heroic and ugly ways), blowing up like a dormant volcano to accomplish great deeds or great destruction. This is because of differences in balance. Types value their dominant, as well as the corresponding inferior (an ISTP values Ti, as well as Fe). However, the 6th function is not properly counterbalanced (an ISTJ is very strong at Ti, but undervalues and is very weak at Fe).
This causes its Hulk-like tendencies—there is no opposite counterbalance to give it context or reign it in. An example is that an ESTP would attempt to gain foresight (Ni) to counterbalance their very strong Se. It is difficult, and the ESTP will nevertheless suffer from not being prudent, but they will try to develop their Ni. An ESTJ, on the other hand, is not only terrible at Ni, but does not value it. Their Se will drive them to take impulsive actions in ways that will get them in serious trouble down the road.
On the other hand, this function may appear weak simply because it is unvalued, and the auxiliary is favored. It is viewed with suspicion, and its methods are doubted. But it is a treasure chest in the attic of the psyche. According to Dr. Beebe, when acknowledged for its value, it becomes a sage. When it is opened, embraced and cherished, it can serve you tremendously. Instead of strain used to develop weak, valued functions, this one comes easily with a little dusting off. With integration into the Self, just like any function or element of the psyche, it will balance the personality. Except unlike the others this function is a secret superpower.