My 5 yr old boy is rather aggressive and this is starting to become a real problem for me (and other parents!). He lashes out at the slightest provocation and mucks about to get attention. He is becoming known as the "problem" child amongst other parents. He understands that hurting is not acceptable but in the heat of the moment seems to forget the message I have been drilling into him ! We have sanctions for bad behaviour and always talk about any incidents and why he did what he did and the consequences. To make things even more tricky a friend of mine is losing patience with my son and is blaming me for his aggression (not always aimed at her child). My parenting style is to be consistent and eventually the behaviour will reduce but my friend wants instant punishments. Any advice ?

Do you think there is any underlying cause for the behaviour? Ask any other adults who look after him (teachers maybe...) if they think there is an underlying cause for the aggression.... (it could be adhd etc). If you think there is no underlying cause.... stick to your guns.... be consistent etc and face up to your friend. I gather that at about the age of 4 boys have a surge of testosterone... that can make them aggressive... could that be the cause?
Ask your friend how she thinks you are causing the problem....
Children are all different. I have a friend who once said to me 'I used to think I was a good parent until I had X and then I realised that Y was just a good child'.Some children are easier than others.... and until you've had a challenging child, you often make judgments about the parenting skills of others when actually, it is just the child!!!
If you are being consistent.... carry on doing that... it will get through to your son eventually and it is your son that matters!!!!

Ask your freind why she is your freind if she doesn't like your parenting style. Point out to her that questioning your parenting qualities is bait for him to act up more and if she can't support you then maybe time to find a new freind that can.

Speak to his teachers about the comments he's getting from other adults (who should know better than to put a child down) and kids (who will simply copy what the other kids and their parents say), from experience with my own children I know that a label of being the naughty kid can do a lot of damage to self esteem and make the situation worse (although if you do find its more than a phase you will get very good at one liners that politely shut them up).

Plus what Nicki said especially the bit about 'its your son that matters'

thankyou both for your comments and advice. My gut instinct is that I am being fair and therefore that I should have confidence in my parenting skills ! But you know what it is like when someone criticises you. It could be the testosterone surge but my son has always been physical and it has been a constant and ongoing challenge to get him to stop and think rather than just being reactive. I don't think it is adhd as my friend's son has that and the symptoms appear quite different. Also, my friend has calmed down about the whole matter. Thank heavens !