Why do people intentionally do harm to someone who didn't cause any harm to them?

[Anonymous]

[understanddd]

Because they are weird, anti social or mentally ill.

I don’t get why some people harm other people that did nothing wrong to them. They obviously have problems and lack sympathy.

Lacking sympathy for others and intentionally causing other people harm is anti social behaviour.

[kylee2437]

Because people don’t know how to hash out their own issues, so they pass their issues onto other people. Very unfortunate

[jshm2]

Because the harm may have been done indirectly, or they may be mistaken about the harm done.