Someone made a joke at another kid's expense — a bit mean, a bit cruel — and everyone laughed. So you laughed too. Not because it was funny, really, but because everyone else was, and not laughing would have made you stand out, maybe even made you the next target. Later, you thought about the kid the joke was about, and the laugh sat badly with you. You hadn't said anything mean. But your laugh had been one more voice in the crowd that made them feel small — and you knew it.