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

"We destroy other people because we're afraid of them destroying us"-my teacher, on the question, KSB, 2018

The way I see it, this is a deflection technique (pushing their pain/issue onto others to avoid it themselves) that can have many different intentions behind it. Sometimes people who are in pain emotionally or physically want to inflict it onto others because they do not want to be alone in their pain, and feel that "sharing it out" so to speak will make them feel better. Much like when you have something on your mind, it often feels better to tell someone right? Another example of this is someone who is in pain purposefully hurting someone else in order to distract them from the fact that they themselves are in pain, or the source of the problem. Either way, most of the time it is not done maliciously. It is done to hide weakness and vulnerability. The best thing you can do is tell them that you understand and you are willing to help and support them through their difficult time, however you are not an emotional punching bag and you need to be treated with some respect. Support, encouragement and love!

People who are in pain sometimes want other people to feel how they are feeling, or they feel so much pain that it turns into anger and they don't know what to do with it.

The reason people who are in pain wish inflict it on hers is all different depending on the situation and person. Some people do it subconsciously while others may not want to feel alone. There's a wise saying "Misery loves company." No one wants to feel they are the only person to experience our pain so if were unable find people similar people tend drag people to their level.

Misery can spread like wildfire. If they are unhappy then everyone around them shouldn’t be able to enjoy their happiness while they are suffering. Emotional and mental instabilities are common frustrations when dealing with problems. It’s good to talk to someone, the pressure will subside and they’ll feel much better.

Perhaps to attempt to release the pain that they're feeling. They may feel that pain upon others may help them cope with their own

They feel that they are being personally wronged by the world and do not want to be the only ones. They long for others to feel their own pain.

Maybe they're jealous of others who are having a much better time than themselves. They want to feel like they're not suffering alone

The person may be feeling out of control and want other to feel how they do, they figure it's something that they can control.

Many people believe that if they cause other people to be in pain it will help them feel better about themselves, it is as if they think they're not alone in how they're feeling