It has often struck me, when dealing with small children, how much they understand versus how much they can express. For example, I read an account in a Mothering magazine article about baby sign language in which a very young child - 14 months, I think? - woke up in the night in pain, and was able to sign to her parents, "Ears hurt. Need medicine." Now, there is no way the average 14-month-old could express that verbally, which goes to show the advantage of teaching your baby sign language. But think of how much more they want to express that they can't even sign. That they wouldn't know how to express even if they could? Suddenly tantrums become much more understandable.
Well, today I had another lesson from my son in which I learned that an almost-7-year-old still can't express everything either. When we woke up this morning, dh and I were snuggling in bed after Samuel got up to get a banana. When he returned, he wanted to be in the middle (as usual) and we said no, because we were in the middle of a conversation and it's hard to talk around a wiggly little boy. He left the room, and I could tell by his body language that he was upset. He came back into the room a few minutes later to tell us what he was feeling. Of course, he chose the most direct method, which was to bring in the trash can from his bedroom, set it next to us, and hurry back out without a word. (Insert Napoleon Dynamite: "Well, what would you do in a situation like that??? Gosh.") I called him back in and asked him to explain and he couldn't. He was clearly upset, but couldn't say a thing about why. I tried to see if there was some deep meaning in the trash can, but he just said he didn't know. I can only guess that it was the first thing in his room that he laid eyes on that wouldn't seem like a gift if he brought it to us. When I asked if he was upset because we wouldn't let him be in the middle, he said yes, that was it, and I was also able to determine that he thought we didn't want him with us at all, and we got it all cleared up just fine. I tried once more to have him decipher the trash can, and he was still clueless.
Most children probably won't bring you a trash can. But they might throw a tantrum, talk back, throw a toy, hit a sibling, or otherwise act out. There's always a reason, we just have to find it.