If more people in this world were both a little more theoretically and practically wise, I believe there would be less violence.
A lot of people you see now lack empathy for others, a big contributor to violent tendencies. Instead of putting themselves in someone else's shoes, they judge others' actions with much bias. For example: say you were walking down the street and a homeless man grabs your jacket, begging you for something to eat. A good amount of people would ignore him and continue walking. Some may even kick or hit him. With a little more empathy (practical wisdom), we'd be able to understand that maybe this man lost his job to no fault of his own, and is stuck in this terrible place.
On the theoretical side, a big thing a lot of people lack is objectivity. This holds true with almost everything: religion, sexual preference, race, gender, etc. With a little more tolerance towards people of different cultures, the world would definitely be a better place, and we'd all be healthier intellectually.