I think some people are sociopaths and don't feel empathy, because that's how their brains formed. Other people might feel empathy, but they're emotionally scarred, or are able to justify their actions to themselves. We can all be selfish, get unreasonable angry, have irrational fear, etc. And if you're raised in an environment where you have to learn certain survival strategies, like street smarts or being tough, then that can overrule empathetic concerns.

Interesting how your environment can play a role in this. At least from my point of view by being unethical to those around you, you're contributing to making the world worse off. That would only make me feel poorly of myself, this is why I struggle to understand those who seem to have a significant lack of empathy.

A person can derive self esteem from within, or they can derive it from outside, themselves. For example, if one is an actor, they need an audience's reaction to feel a higher sense of self. An entertainer without an audience is not as full. On the other hand, there are people, such as the pioneer, whose self esteem stems from their own actions and comes from inside of them.

Empathy comes from inside us and causes our energy to leave us, so it can be given to another. The mother senses the needs of her child and outputs her loving energy to them.

A bully or those who appear to lack empathy are more used to drawing in energy, from outside themselves. The bully likes the induced fear reaction as an input for self esteem. They are more stingy in terms of their own energy output and only use it to induce others to output for their self esteem. They can empathize, but only if they feel full, which is not all the time.

We can all empathize, but we all do the math and make sure we don't drain ourselves. We may budget out empathy and give it to those who are empty and need to feel full.

Sounds like a stereotype of people you decide to label "bully".

Interesting how you also display a lack of empathy here.

Well it's not I'm asking about general trends, obviously everyone is an individual and there are going to be exceptions even if you can find such a generality, your far too eager to interpret what I say in a negative light.
To the second point yes that's correct, my error I'm talking about a lack of sympathy.