How do you discourage a toddler from hitting people?
Out of the blue my 16 month old son has started hitting his sister (4 year old) and other kids when he is frustrated (and sometimes he did it pro-actively without any clear reason). In those cases he would just walk up to his sister (or mother on one occasion) and just swing at them without any apparent provocation from their side.
This is worrying me, so I wanted to get advice on how to deal with this as he is too young to take any conversational feedback besides just saying "No" but that doesn't seem to be stopping him so far from doing it again. I can't see timeouts or similar things working for a 16 month old.
Any suggestions for how to deal with this issue on a kid so young?