I've got a nearly 5 year old. He's intelligent and his understanding of stuff is excellent. He's very switched on and has a good grasp on his second (fluent) language in school. He's great at his maths and loves building with let, to quote 'He's a bright boy' says my mother in law, (who is a former Oxford university lecturer - very academic and clever lady). He's lovely with his 2 year old sister (standard brother behaviour).
BUT, his bad behaviour is so unpredictable and he's unpunishable. He's destructive, having pulled off newly renovated paint from our interior. He's bitten the side of his bed, he's rough with other children. He throws things, lashes out - hitting kicking etc. I buy him really comfortable and expensive school shoes (sized and fitted so his feet grow properly - he rips out the insoles in less than 2 weeks! He's bitten and broken three water bottles, cut holes in 3 school jumpers and the list goes on. Nothing works to discipline him. It's really worrying.
At the same age as my little girl, he was really a handful and had a lot if intense tantrums.
So. Am I doing something wrong? (I'm quite a strong willed, but not destructive person).
Have I got unrealistic expectations for him as he's just turning 5?
Is this normal behaviour?
Some advice or even constructive criticism would be great