We've come a long way from the caveman days, when problems were solved with a grunt and a club to the dome.
Sure, things were a lot more barbaric at the time, but they were also much more simple. Someone stole your girl? Kill them. Did they try and invade your cave? Kill them. Looked at you with a furrowed brow? You get the idea.
Here's a bunch of straight-up savages that show we're all just animals at heart.