How do humans distinguish sarcasm from sincerity?

Most of us are pretty good at picking up on sarcasm. Quite frankly, we have to be. Much of the way we communicate as a modern society is structured around subtle contextual cues that tell us whether someone's mockingly contemptuous or earnest. Many of us can even pick up on sarcasm when it's conveyed entirely via text. » 11/17/11 2:40pm 11/17/11 2:40pm