I actually think this is something of an INFJ coping mechanism to prevent hyper-empathy. I was reading a book called "Why We Hate", by Jack Levin and Gordana Rabrenovic, recently and it said that as humans we only empathise with people in our "group". It went on to say that if we cared about the plights of every group, we would suffer from hyper-empathy and we would breakdown.