This fact is well known. And we can see this principle in action every day in the news. Muslims, though by nature may be the sweetest people in the world, but after many years of imbibing the lessons of the Koran can one day wake up and decide that today is the day for Jihad and to go out in a flame of glory by killing a couple of Jews or Christian infidels.
But I would like to suggest further that certain organizations can reinforce specific types of evil, while at the same time be lessening other types of evil.
A good example of this would be a school which does evil by emasculating the boys that go to it and yet lessens other kinds of evil.