Here is something I think everyone needs: understanding and empathy.
That's actually two things. But maybe it's one thing collectively.
I think the cause of every social problem in the world is caused because of a lack of understanding and empathy. It works on a macro and micro level.
For example, if you are going through something really hard, conflicts start when other people don't understand it, and they get impatient and annoyed. Friendships can disintegrate. People can stop trusting each other and relying on each other for support.
And wars all start because of a lack of understanding. Racism stems from it too. People don't understand how other people feel, even if what they feel might be irrational. And sometimes people don't want to step outside of their minds to accept what someone else is feeling. We don't really want to be open to new ideas. We just sort of want our ideas to be right, and even if we are wrong, we don't want to accept it.
The war of childhood - bullying - also starts with a lack of understanding. We only know what people tell us. That's it. And we sometimes we are bullied for what people think we are. No one can ever know everything about you, and they aren't supposed to. But bullying is when people don't understand, nor care, about what's really going on.
Try to have empathy and understanding for people, even if you can't quite understand. Just try to imagine yourself in a similar situation.