You’ve spoken really well, Yechee.
Interestingly, I have seen parents who are still really harsh to their own children and that makes me question whether it’s really due to biological factor.

For me, I'll say it's not just in people to be completely kind towards others because for those that are genuinely kind, they don't mind going the extra mile for strangers and that's what we all have to work on. We have to learn to be more gracious and kind towards the need of others, whether related or not, only then can we truly do better in this regard. It’s hard and that’s why I always admire those who have done and are doing well at it.