Empathy for Psychopaths

The factors that lead to our mental state are secondary to genetic inheritance.  Some people, from birth, form strange modes of thought in their neural formative stages.  These may be affected by events before birth.
The mother’s emotional and physical states can affect the development of the brain in a forming fetus.
While claims of alcohol and drug use affecting a developing fetus are probably overstated, there is a high probability that these could be a factor.
So, the genetic makeup gives a foundation for the developing brain.  Any errors or abnormalities here will of course affect everything that comes after.
The neo-natal environment then becomes a factor.  Events in utero mark the cell growth of the neurons that will form a baby brain.
The birth process itself can introduce changes to the brain, usually by physical damage from contractions or manual extraction, but also lack of oxygen.
Once born, the brain must go through several development steps.  Brains, like fingerprints, are unique and are created in billions of tiny steps.  Each forming brain has to find the neurons that are sensation, and figure out where those sensations are on a map formed by experience.
Each subsequent experience molds the neural pathways, and billions of potential paths are lost as the growing brain adapts to use the experience to organize thoughts and feelings into systems or behavior.
After all of these stages, some brains discover a way to express feelings and others wall those sections off and never develop those neural processes.
Some of these individuals will be so disconnected from emotion that they become a slave to the desires of the pure, unfiltered impulses of the animal body we inhabit.
Once the brain adopts a pattern, it tends to keep that pattern.  So once the development moves to extreme self-involvement, it reinforces the prior tendencies to be isolated and hostile.
If this is you, then your ability to be empathic is damaged.  You must consciously create the behaviors that most people would exhibit normally.  We must teach ourselves to observe social conventions, to be aware and respond to the subtle signals that ordinary humans intuitively react to.  We must by force of will and intellect, emulate a normal functioning human.
Lastly, we have to form deliberate patterns of behavior to reassure the rest of the world that we fit in.  It is by controlling our desire impulses that we can create successful behaviors that increase our acceptance in groups, and by contributing to society at large that we can derive personal satisfaction and a sense of our positive self respect.
We who cannot love others also cannot love ourselves.  Deliberately inventing a sense of purpose and the resulting feeling of accomplishment will, over time, become a motive that will help bridge the gaps in our lives.