
It's actually both. There was a research involving identical twins separated at birth. Thet were good subjects to test out the nature vs nurture idea since they are basically the same person brought up at different environment. Iirc, what was found was it was both. The twins showed some similar mannerisms and likes and such, but they also showed differences due to the different environment they grew up in.
People are simply not the same.
Some will see the glass half full.
Some will see it half empty.
Some abused people will grow up highly empathetic because they don't want other people to suffer like they did.
Some abused people will grow up highly violent because the suffering and pain they experienced made them bitter and hateful.
Some people are weak. Some people are strong. That's just how life is.
notice how yeongwoon was similar to jaekyoung getting abused by their fathers but the former didnt end up shitty like the latter? yeah.