DS is 20 months. He is the youngest of 3 (his sisters are 5 and 3). He has always been an adorable, giggly easy tempered little thing and we all adore him. His sisters shove him around a fair bit but basically they are kind to him, look after him, play with him and entertain him non stop.
Recently he has started hitting and pinching (real pinch and twist painful stuff) and hair pulling (clear grab and yank) etc. Basically the minute that he doesn't get exactly what he wants he will lash out. He does it to me, DH, his sisters and also to other children (friends of his sisters or worst of all other little ones his age - pushes them over, shoves them out of the way, hits them, grabs what they are playing with etc).
I'm just not sure how to nip this behaviour in the bud. When I say 'No, don't pinch' or whatever, he giggles and says 'sorry.... hurt... kiss better' and goes to kiss whoever he hurt, which is all very well, but has no effect on the fact that he will do exactly the same thing 2 seconds later. I tend to remove him from the situation, put him straight down and give lots of attention to the 'victim', meanwhile he'll be hitting my back or something like that.
He's too young for time out etc. How do you stop a 20 month old from doing this?
DD1 went through a biting stage when she was 2 and a half but I found it easier to deal with as she had more understanding of cause effect and consequence and responded to withdrawal of attention / losing favourite toys / short time out.