Why would someone who is already in pain wish to inflict it upon others?

It makes them feel better aboutique themselves because perhaps they are being bullied by someone else or being abused at home etc

because they feel the need to drag others down with them. Don't let them do it, instead ask if they want to talk and just be their friend

Because they don´t know how else to cope, I think. When you are in a lot of pain, some of the time you do end up inflicting it on others. That can be a reaction of feeling jealous that someone might have it better than you emotionally or just generally not knowing what to do with all of the pain that you feel.

as an act of revenge...or...simply the same way an injured elephant flings itself around and hurts everyone else...the elephant is only trying to fling the pain away. Not understanding that flinging does ..nothing.

I honestly think as humans we don't wish to do this however sometime we have to be aware of the impact if our actions. Honesty is always best and listening to each other is the only way forward. I remember a girl friend asking me what a guy meant by his behaviour and he stopped calling. He stopped calling as he had lost interest! He just isn't into you. We gave to be honest and listen to each other.

To make themselves feel better, as if they aren't alone in their pain, and need somewhere to put out their energy and frustrations.

When people are in pain sometimes they look for an outlet to deal with that pain, and for them, it may mean hurting others. Some people have low self-esteem or feel powerless and being horrible to others may make them feel better about themselves.

Because they have repressed the anger and frustration within them for a long, long time and haven't taken any steps towards getting out of the pain. Inflicting pain would become second nature if not addressed in time.

Many people who are in pain are in a place where they handle things out of emotion instead of rationality, which causes them to do things they wouldn't usually have done. I feel like in most cases, it is not someone's wish to inflict it upon others, but an unconscious to react to what has been happening to someone. Many people reflect what has been done to them onto other people. For some, they also see the infliction of pain onto others as the last way out of their own misery. Though some people hurt others on purpose, many people who have suffered don't do so.

I would say that the person themselves are suffering and maybe that they don't know they need help, but their actions speak otherwise. To give an example, In the film It's Complicated, there's a scene when the kids find out that their parents might be getting back together, and one of them makes the comment, "We still haven't gotten used to the divorce yet." Then, when things don't work out for the parents, the kids are all in bed together, teary-eyed from the confusion. Another example is that If your life or a relationship is going badly, revenge is not your last hope for renewal. In fact, it takes away much more than it gives. Trying to figure out how to get back at someone uses up time that could be spent in many more positive ways to heal your self.