Anxiety is often the result of an internal psychic conflict, and one of the most basic conflicts in the JCF typology scheme is that of two opposing attitudes, introversion and extroversion. A loss of confidence in one's self (perhaps due to an emotional trauma) causes the individual to fall back on the traits of the dominant function. As a result, the introvert becomes even more introverted due to a denial of the extroverted function, and vice versa, along with pushing forward the tertiary which has the same attitude as the dominant.
At a previous time in one's life, before the traumatic incident, the functions were in healthy balance. There was no anxiety involved with dealing with the internal realm (e.g., math anxiety) or the external realm (e.g., acting on the products of one's thinking), although there will probably be some issues with the inferior of a type (e.g., the ISTP child who has no problem learning to play the piano but has debilitating stage fright when confronted with an audience).
In the interests of developing a healthy self-esteem, the auxiliary type demands attention, and self-esteem drops whenever it is ignored. It may arise nevertheless in odd ways disconnected from the dominant function. Se-aux, when not in a cooperative mode with its dominant Ti or Fi, babbles on disjointedly about trivial issues. Ne-aux does the same thing, but it babbles about other-worldly things such as UFOs, outer space, and mystical notions. This is merely an aimless extroverting of a mental content derived from the activity of the auxiliary that requires some outlet but has nowhere else to go.
I'd like to hear from those on this forum who think their auxiliary is active yet disconnected from their dominant function. I'd like to know how it expresses itself in pointless ways, for example, the Fe-aux of the INFJ.