Cinema Science

This is from Roger Ebert's review of Superbad. It doesn't have anything to do with the movie, I just liked the story he told at the end.

In its treatment of adolescent sexual yearning, "Superbad" remembers not only the agony but the complete absence of the ecstasy. I remember in eighth grade some kid asked how long you could entertain an impure thought before it got upgraded from a venial to a mortal sin. "There aren't rules for things like that," the sister explained, "but I'd say that after five seconds, you're asking for it." The kid and his buddy went down to his basement to study his dad's collection of Playboys, and he got a stopwatch and had his buddy punch him in the arm every four seconds.