There are so many ways people are kind to each other: in little things and big things, in times of danger and in times of peace. If children were praised more when they did caring things, if those caring gestures got the same attention as a good grade, a sports success, or any other kind of win, do you think that perhaps there would be more kindness in the world? If corrections and punishments were balanced with more kindness, would it help?
People are kind and cruel both, but if the cruelty is rewarded more than kindness, of course it happens more. Too many people crave attention so much that they will do anything, even act badly, just to get it. But most people have to be trained to kill, to see others as an enemy, or to shun others, or they have to feel that there is no other way to get the rewards and attention they need. So stop and think, before you do something bad to another person: “Why am I doing this? Is it really because I hate them or because I am hurting inside from something else, like not being loved enough myself?” And then go and find another way to fix your own pain first.