The One Percent
Heard at the criminal courthouse:
We are 99% animal and 1% civilized, and it's the one percent that gets us into trouble.
It's true, I think. Not because the one percent of us that is civilized motivates us to do the bad things that get us into trouble, but because the one percent likes to pretend that the 99% doesn't exist. Like Paul Smith says, "I Spent Most of My Energy Hiding Myself From Me". (Paul's talking in terms of his "real self" and "false self"; same thing, for my money.)
Most crimes-most mala in se, at least-do not have complex motivations: they're motivated by a) anger; or b) fear; or c) both. The murderer might be angry at his victim. The rapist might be afraid of losing respect when his impotence is recognized. The thief might be afraid of losing his position in the pack.
Fear and anger are powerful things. But we all feel anger and fear, and most of us keep them under control most of the time.
A key to controlling powerful forces (fire, atomic energy, anger, fear) is recognizing how powerful they are and respecting that power. If we honor our animal nature, most of us are able to keep it directed toward socially-acceptable behavior (while reveling in it on occasion in socially appropriate ways).
If we turn our backs on the 99% of our natures that is primeval, though, and become convinced that we are the civilized part (we tend to agree on this fiction by consensus: we call people who do bad things "animals," as if we are somehow not animals, or "predators," as if we are somehow not naturally predatory), that is where the hundredth part can get us into trouble.
Once the one percent has convinced us that we're all civilized, the 99%-all of the reptilian brain and mammalian brain, and most of the ape brain-is free to do what it evolved to do: take over and drive us to do things that, while they would be appropriate among reptiles, wolves or apes, tend to be frowned upon by human society.