Michael Smith, the Martian of Robert Heinlein’s 1961 novel Stranger in a Strange Land is having a lot of difficulty in understanding what makes up that strange creature he has just encountered for the first time, the “human.” A trip to the local zoo and a cage of monkeys provides the answer for him. There, a peanut is thrown to a small monkey who takes it eagerly. This monkey is immediately bowled over by a larger monkey, and the peanut is stolen from him. The small monkey runs away howling, until it tracks down an even smaller monkey to beat the daylights out of. The rest of the monkeys choose to ignore the entire incident altogether. At this, Michael begins to laugh uncontrollably, so hard that he is unable to stop for hours. A revelatory moment, at last the Martian has understood (in his idiolect, he has “grokked”) that fundamental secret of what it is to be human:
“I’ve found out why people laugh. They laugh because it hurts-because it’s the only thing that’ll make it stop hurting-of course it wasn’t funny; it was tragic. That’s why I had to laugh. I looked at a cage full of monkeys and suddenly I saw all the mean and cruel and utterly unexplainable things I’ve seen and heard and read about – and suddenly it hurt so much I found myself laughing” (Heinlein 289).