The natural enemy of robots

[Dalex]

Perhaps not a surprise if you think in terms of violence committed by humans against other humans. It starts high, in infancy, and drops dramatically between birth and the mid to late twenties. We notice the violence more in teens and young adulthood because by then people have near-adult size and strength and intellectual intelligence; though their inclination to violent behaviour has actually dropped quite dramatically from the time they were toddlers they are far more able to inflict damage when they do occasionally lose their temper and good judgment.

This is logic behind Warhammer 40k Space marines.