Having three teenage boys ages 14, 15 and 16, I definitely have a a few thoughts that you might find useful. When they were little, I made them hug which I saw another mother had already suggested. However, by 10 and 12, hugging turned into squeezing which obviously didn't work. Two things have continued to work. When they are especially argumentative, I do not allow them in the same room or to speak to one another. This works well because they do like one another and want to spend time together. Sometimes they just forget. Another thing I do is make them stand in a sort of nose to nose position. They cannot touch one another, but must stand facing one another very very closely. Trust me when I tell you that they will HATE this at first and will throw daggars with their eyes, but invariably, standing this way (for however long it takes) forces them to want to work out their issues on their own and in a civilized manner. Do they still end up in brawls sometimes? SURE! They're teenage boys and frankly, I'd rather them learn to fight here than on the streets, but these techniques keep fighting to a minimum and have helped seal their relationships with one another. As the saying goes, "To love is to be willing to get down on the wrestling mat of life yet be able to get up and hug when it's over."