Normal children do not bang their heads against walls or attack doctors and say they’re going to kill them when having a tantrum. They also don’t say they hate themselves when fighting with siblings. They say they hate their siblings. Normal children may still throw very rare tantrums at that age but meltdowns over trivial or inexplicable things should be long in the past.

I would not so casually dismiss an underlying issue. Children misbehave for other reasons than they are spoiled or undisciplined.