Which actually means "I've pretended to suffer it and you are probably too".

Empathy is definitely a learned trait that develops slowly. Children generally start off treating life as if it has a preset plot and other people as sort of NPCs or characters in their life. Realising other people and even animals experience things at all should happen at some point. And realising their experiences are different again later. But it's a complicated process and may even fail.

https://www.psychologytoday.com/us/blog/smart-parenting-smarter-kids/201905/how-children-develop-empathy looked pretty good from a quick search. Otherwise that's just my memory from basic psychology classes.

getting beyond ape-brain requires a lot of learning and practice. like any skill.

depends on your genetics and the environment of the womb, brains are pretty complicated and behaviour is affected a lot by that kind of stuff. there exist people who mostly or entirely lack empathy after being born and there are people who are ultraempathetic, and there's a ton in between.

there's also a difference between "cognitive empathy" (the ability to recognize others' emotions) and "affective empathy" (how you emotionally respond to your perception of others' emotions). something also associated with empathy is the ability to distinguish between yourself and others, i.e. how well you can put yourself in their shoes rather than think of their experience from your own perspective.

a lot of people suck at the last one, which is bad because even if you have positive affective empathy and can share others' emotions, you still may not be able to really grasp how they feel and you'll probably think that they're overreacting or underreacting or reacting wrong because you can't imagine yourself acting the same way if you experienced the same thing. many people are subconsciously sexist or racist because they see someone dealing with casual sexism and racism and think it's not that bad, just brush it off, but they can't relate at all because they don't have the same set of life experiences and same psychology as other people. to them it's "i wouldn't react that way if someone did that to me, so you shouldn't either".

it's usual for humans to have enough empathy to survive as a pack/society at least, but it's also usual for humans to not have a mood disorder and it's usual for humans to have 5 toes on each foot. in some "societies" like american capitalism, less affective empathy is usually advantageous with high cognitive empathy, and more affective empathy is usually a disadvantage, which is kind of the opposite trend in humans.

a lot of the times when it seems someone lacks empathy, they either don't express their empathy in typical ways, or conditions (like culture) require them to silence it to be successful. but they could also just lack affective empathy, or have dissonant empathy (affective empathy entailing an opposite emotional response than what you would expect), both of which are typical anti-social and narcissistic traits.

why should anyone be thought of as scary by other simply because of how they were born, people shouldnt look at someone and assume they are gonna start killing people just because they are big or a man, that is wrong it is wrong to think that way and the people who do should change.

I mean the idea that if people perceive u as dangerous for no good reason they should act as if u were dangerous and thats just something u have to deal with is ridiculous, in any other context this line of reasoning would be considered obviously wrong if a white person acted as tho all black people were dangerous they would be rightly called racists and be expected to change their behavior so why should it be any different with men, why is it suddenly ok good even to uphold the patriarchy against men, this is ridiculous if people feel afraid of u for no reason u should challenge them on it and question it not just accept it as if it were normal.