There evidence of numerous studies do not support that conclusion. There is "it depends." It doesn't work to deter unwanted behaviors in children. All it teaches them is "what mamma don't know won't hurt." If anything, it makes them better at covering their tracks than getting them to not do that again.
And yet often we hear complaints of the police being wrongfully violent (police are supposed to only resort to violence when it comes to protecting themselves and others). And clearly there is a huge difference between military violence and doing violence to someone for doing something you disapprove of.
Let me use an example to illustrate how I think violence works positively:
(just saw on the news a few days ago someone being viciously attacked by a young gangster.)
I walk through this wicked person's infested territory. As he attacks me because of what he thinks I posses, I use my superhuman powers to beat him to a pulp. I leave.
I come again a few days later, this time he brings backup, and tries to get me again, I beat them all up to within an inch of their lives.
This happens one more time, I break a few of their bones, and leave them in major pain.
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What do you think happens if after all attempts on my person end up this way.
Will they stupidly continue their attacks or will they come to leave me alone and go after an easier target! (not speaking about guns - just trying to use this example as just that an example)
Violence works as a deterrent..
Though I am not superhuman, I am experienced with violence and how these people think.
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So, while I agree that it would be really nice if we didn't have to resort to violence, I think it is a must to use it.
Bullies in classrooms need to be taught a lesson of pain according to their behavior.
At times, teachers have a thankless job, a really hard job. There needs to be times of pain, but strictly controlled, taught by experts so as not to be misused, perhaps enforced by special enforcers.