Physical fights between children, particularly siblings, is normal.
Fighting between brothers is a natural and dare-I-say-it healthy occurrence.
In our house there is an almost daily punch-on in one form or another. It could start as simply as being breathed upon too heavily while sharing an iPad. Or by copping a rogue footy in the nuts.
There is rarely an intent to kill.
Rarely.
My wife thinks it’s because they watch YouTube clips, play video games and watch movies with violent content.