Its mostly me that my almost 18 month old hits, but he also hits his granny, our dogs, the cat, his dad... so far he is too shy around others to interact much with them, but I would like to nip this thing in the bud. I try to do the "high five" thing and explain to him that we don't hit people or dogs, etc. He also throws books and wooden blocks at us, which can do a fair amount of damage and cause reactions that might not occur if one had time to think! I don't want to be a yelling parent! This has been going on for several months.
Anyway, I don't have much knowledge about how to correct this behavior, or steer this behavior in other directions... I'm on the site to find answers, too!