I've personally experienced a hardship after which I pretty much dropped Fe and effectively became 'unemotional'. Not really a sociopath, although I suppose I appeared as one.
By focusing more on Ne, and neglecting my Ti (because Ti was too hard to fool). And ofcourse usage of alcohol (So I didn't have to bother with Ti), I thought was the only way of dealing with the trauma. Since using Fe would just be like a bomb going off and ultimatly I wanted to prevent myself from doing more harm. However, I did feel like I just wanted to be 'along for the ride'. Essentially unexistant. I wanted to be a shadow amongst people.
After some time, in a rather confronting situation (approximatly 2 years after the traumatizing event) the realization came that I really needed to change.
This is when I developped a strong Fi over the course of a year in order to put everything back into perspective and align myself once more to society. Now, I had no knowledge of cognative functions at the time, this was a natural process for me. But by starting focusing inwards, feeding an internal 'scale of justice' with my Ti-Ne. Processing information with the aim to live a better life. As well as the realization that Ti-Ne is not infallable. And that life is too short to live solely by facts. I felt I had to fill in enough gaps with Fi. So I did, dealt with the trauma and ever feeling awesome and great now. Within reason ofcourse. As far as my Ti allows.
I notice much more INTP's with a high Fi as well, and wondered if they too got it, due to dealing with hardship?