I agree with a lot of these answers. Of course hitting is sometimes fueled by frustration, etc. However, it should not be ignored, especially if your son hits his parents/siblings or other children. My daughter started to pinch at this age and we broke her of that habit pretty quickly once we started addressing it firmly. At this age, words don't mean much but big gestures matter - like leaving a location - whether it's a store/party/your hip. Our big turning point was when my daughter pinched a little boy in her playgroup after about 20 minutes of being there. I just walked over, told her firmly "we don't pinch", made quick apologies to the others and walked out the door. Anna was confused but I could tell she was starting to get the point. She pinched again that night and the next day - both times I put her in "time-out". The BEST time out method is John Rosemonds and he explains it in, "How to make the Terrible Two's terrific". I recommend this book!! Basically, put your son in a chair saying, "This is time-out for hitting. You need to sit here until I tell you that you can get up." And as soon as you let go of him and start to stand up, you quickly say, "you can get up now." Of course this can only last a total of 3 seconds since you're dealing with a complete wriggle worm that doesn't really understand, but he will get the point - you are in control and he needs to listen to you. If he's like my daughter, he will hit you again within minutes - do it again repeatedly. It took Anna a couple series of time-outs and that was seriously the end of it. And it involved very few tears!!