The Australian Psychological Association advises againsts smacking
In a recent release the Australian Psychological Association acknowledges that summer holidays can be stressful for parents and advises that smacking is not an effective way of dealing with unwanted behaviour. The release reminds us that physical punishment can have unintended consequences such as damage to the parent child relationship. It suggests to that parents may find it helpful to identify ways of calming themselves before they deal with their children's unwanted behaviour - taking deep breaths, walking away for a short time or playing some music.
The assocaition has produced an online guide to managing behaviours such as bullying and aggresssion and fighting. It can be viewed here
http://www.psychology.org.au/publications/tip_sheets/bullying/