INTJs and ISTJs tertiary or relief function is Introverted Feeling, Fi. This function is a bit quieter for these types than for Fi dominants or supporting. It works behind the scenes, often leaving the user unaware that a Feeling function is even in play. In the tertiary position, Fi is responsible for creating deep and lasting emotional connections and creating a moral compass.
Don’t let INTJs or ISTJs fool you into thinking they’re emotionless. It’s just that they apply their emotions very selectively. Fi, in these types, is not flighty reactive emotions, but instead builds bonds that endure.This is what cultivates deep and lasting friendships, fuels their passions, and cultivates their immutable (though highly personalized) code of ethics. They may never cry during a movie, for instance, but may be completely devastated at the finale of a TV show they’ve been following for many years.
Much like how you have to wait for ESFPs to process their emotions before they can think logically, INTJs and ISTJs must process thoughts and experiences practically and analytically before they can truly experience the emotional core of a situation. If a loved one were to die, for instance, they may not experience their emotional response to this until after the funeral is over, the will has been read, and any other loose ends have been settled. There is a delayed response between something happening and the tertiary Fi processing it.
While it keeps our INTJs and ISTJs level-headed, there is a downside to this. Often, they are the last to know what they are feeling, leaving their loved ones to roll their eyes until their I_TJ catches on. They may become overwhelmed and unable to react in highly emotionally charged situations. Their romantic partner may do something hurtful, and they won’t get upset over it until hours, days, even months later, leaving their partner to feel like the I_TJ won’t let go of old wounds. Speaking of which, these types do in fact take quite a long time to recover from loss, betrayal, and other hurts from those with whom they have formed deep bonds. This is also where judgement comes from — not the J function, but thinking less of others for not measuring up to the I_TJ’s sense of values.
Unrelated Note: I have recently noticed that the images from this blog have been shared on facebook, pinterest, and other websites. That would be great, except many of these people are cropping out the source watermark. I’ve always tried to keep this source annotation off to the side so as to not take away from the image, but now I’m going to have to start putting it in a more central location. I hate having to do this, but, well, this is why we can’t have nice things.