According to Golding, all people have within them, a basic human fault which is evil. He felt that the constraints of society and the manner in which we assimilate into society keep that evilness within. In "Lord of the Flies", Golding describes the evil fault within mankind as an "inner beast". We see it come out as the boys gradually grow more and more savage. In today's world, which is really no different from Golding's world, the beast could come out in many ways. Golding had served in WWII and he saw man's inhumanity to man in that arena - war. We still have wars and it is there that people turn savage against one another out of necessity, in the same way that Ralph grabbed the sharpened stick to use as a weapon. It often comes down to kill or be killed. The beast comes out in smaller ways, too. Anytime a person is purposely unkind to another person, that evilness is coming out. Anytime a person cheats someone or deceives another person, that inner beast comes out. Crimes of violence are also examples of the inner beast emerging. If Golding is right, then mankind is constantly in battle to keep that inner beast inside.
Your first answer is great, but for examples, what about an inheritance squabble which leaves a family divided, or mobbing (or a secret stab at a rival) at the office when several people are vying for that coveted job? Then again, there's that age-old classic of sexual jealousy, along with the compulsive urge to dominate.
The film "Bride Wars" is a situational comedy based on this idea, but in real life such an "out for blood" instinct is no laughing matter....