Who are we?
Adrenaline, which is in fact just a human hormone, is very powerful weapon. But this weapon isn't wide spread yet. Or it's better to say already.
When life was born in lands of Egypt, it was necessary to control people. And Egypt tribes chiefs, who were much more cleverer, than Indian chiefs, invented few simple rules, to keep their people under control. This rules were fathers legacy to the son. This knowledge were passed from chief, who lately became a Pharaoh, to his child.
Nowadays you can get such knowledge only in special school, which is under government supervision. But even if you somehow get in to such place, you'll find it pretty boring. Because all dirty work is done already. Nobody needs to create new religion, or new culture for your nation. All you'll learn in there, is only history manipulation system. And maybe exactly you'll be the one, who will turn Hitler to a new messiah, instead of murderer.
If you still think that some people are cruel, then you should ask yourself why are they doing it? But you should keep in mind one thing, the more hormones in the blood, the more you'll behave as animal. Different hormone means different result.
I guess you noticed that I didn't mention the global food trade system, which now is in the first place by global profit, but this is completely different story about how to take our hormones level in right place to control us.