Self-domestication

Have you ever noticed your thoughts drifting? Just randomly, you catch yourself thinking something and you have no idea why?
At least once you must have caught yourself planning the perfect murder? Maybe it's a stranger on the train or someone you believe did you wrong... but out of the blue you imagine killing them in some creative way or planning exactly how you'd get away with it. Why?
But more importantly, what stops you?
You shake the thought from your head and you go about your life, maybe it happens again, maybe a few times but everytime something stops you.

Maybe the world was too obsessed with crappy crime shows, spending hours watching CI or Sky Crime... youtube videos of mysterious disappearances. We became so desensitized you'd find yourself laughing at the killers stupid mistake, thinking you could have done it better. But this is all premeditated murder, conscious thought to end another person's life.

What about reactive violence?
There's a theory of domestication, the idea that domesticated animals share certain traits that are side effects of breeding for less reactive violence. The theory goes that humans have these very same traits; that overtime, through capital punishment and females choosing less violent males, the human race self-domesticated. We became friendlier, more cooperative, formed a society with lower rates of reactive violence. Evolution might be what's stopping you now, but what if it doesn't?
Everyone knows that a tamed animal is unpredictable, capable of violence, even dogs can bite. What if one day humans went wild again?