Free Ha! by Scott Weems Page A

and consume gin. Some humor actuallyexploits these seemingly ignored incongruities, as seen in the long history of elephant jokes:
    Â Â Â Â Â Â Â Â  How did the elephant hide in a cherry tree? He painted his toenails red.
    I personally love elephant jokes, not because they’re clever but because they make fun of the very concept of surprise. The script opposition at the heart of this particular joke is the least salient aspect of a tree-climbing elephant. Never mind that any tree would surely break under elephantine pressure, or that pachyderms don’t have opposable thumbs for climbing, much less fingers. What I really want to know is what color were its toes! The whole joke is absurd because its most highly activated script, elephants, conjures up thoughts of size and weight, thereby undermining every other aspect of the joke.
    Research has found that such background incongruities aren’t just tolerated, they make jokes funnier. I’m referring to a series of experiments by the psychologist Andrea Samson at Stanford, who instructed subjects to view cartoons that either included background incongruities or omitted them entirely. For purposes of experimental control, two versions of each cartoon were used: an “extra-incongruity” one and a realistic one. Subjects saw mixes of each and were tasked with rating how funny they thought each was. For example, one cartoon showed a mother and father penguin standing in the Antarctic wilderness, celebrating with wild gesticulations: “He just spoke his first word,” one says. “Great! What is it? ‘Mama’? ‘Papa’?” says the other. The second panel shows both penguins standing next to their offspring, who is exclaiming: “Damned cold!” In the realistic version, the words remained the same but penguins were replaced with Eskimos.
    Samson found that subjects preferred the jokes with background incongruities. Penguins, apparently, made the jokes funnier.
    To see what all this has to do with resolving, let’s take one final look at the brain, this time using an electroencephalogram, commonly known as the EEG. The experiment was conducted by psychologist Peter Derks for a 1991 conference held by the International Humor Society inOntario, Canada, and it involved the measurement of subjects’ brain activity using electrodes placed strategically along their scalps. The electrodes couldn’t tell what the subjects were thinking, but they did show when their brains got particularly busy. While hooked up to these electrodes, twenty subjects read a series of jokes, each ending in a final word providing a surprising punch line. At the same time, Derks and his colleagues monitored the zygomatic muscles controlling the subjects’ mouths, a useful method for scientifically determining whether someone has laughed or smiled.
    When the EEG data were analyzed, Derks saw that the subjects produced two very different electrophysiological responses to the jokes. The first was a peak in activity called the P300. This occurred about a third of a second after the last punch line word and took the form of a sudden, positive spike in electrical activity. In short, the subjects’ brains got very busy pretty soon after the jokes were completed. Then, about a hundred milliseconds after that, the EEG showed an N400—a negative deflection also representing a sudden increase in electrical activity, again due to increased brain processing.
    A couple of things about the EEG are important to note here. First, the positive or negative nature of any observed EEG effect is meaningless because it depends on the way neurons are oriented in the brain, which has nothing to do with how we think. Second, and more importantly, the timing and identity of the observed electrical potential mean everything. In fact, the P300 effect has been observed in hundreds of studies, if not thousands. From these studies, scientists have