My ten-year-old son, Elliott, has several distinct laughs in his repertoire, each precisely tuned to the subtleties of the situation. An under-the-breath snicker connotes mild amusement, like the punchline to a Laffy Taffy joke; a nasal, high-pitched giggle is a response to inspired silliness, like a Calvin & Hobbes comic strip; a deep, hiccuping guffaw from his lower belly signifies his highest level of appreciation, and is usually reserved for gags involving bodily functions. I heard all three laughs, and a few new ones, in the sixty minutes it took him to devour Jeff Kinney's The Ugly Truth, the fifth installment in his Diary of a Wimpy Kid series.