On some blog or other, I came across this laughing baby:
In this clip, the baby's (I assume) father hands him a piece of newspaper, which he has started a tear in, and when the baby takes it, it tears into two pieces, causing the baby to crack the hell up. Over and over again. It's really very endearing.
And later I was thinking, why does this make the baby laugh? Is it social laughter because the father is laughing? And I remembered that one reason people laugh, perhaps, is that something unexpected has occurred.
So you're a baby, right? And you've probably just gotten this whole "handing" thing sort of down. People push an object towards you, and you reach for it, and then it's in your hand. Neat! Now the objects handled by babies are usually plastic, or cloth, or some kind of food. Newspaper isn't something a baby generally has much use for.
So here you are, and something is held out towards you, and you take it. And then what happens is that the object makes a noise, and somehow comes apart into pieces, and you and daddy both have one now.