5 Great April Fool’s Pranks and Why We Fall for Them

Last summer I learned about an April Fool’s prank that started me thinking about the psychological reasons that some pranks and jokes are especially effective and memorable. (That prank is #1 below.)

5. Conversion to Metric Time. On April 1, 1975, an Australian TV news program announced that the country would be switching to “metric time”—converting to 20-hour days with 100 minutes to the hour, and 100 seconds to the minute. Interviews with government officials and a display of a new “metric clock” helped fool lots of viewers.

Pranks such as this one (a later, similar gag announced that the internet was going to shut down for two days so that it could be cleaned) are effective at fooling people because they deal with technology that we all use, but most of us don’t really understand.

4. Smell-O-Vision. In 1965 the BBC aired a report about a "professor" who had invented “smell-o-vision,” a device that would project smells through your TV into your home. To demonstrate, the professor chopped onions and brewed coffee on air. Viewers called in to let the station know that they were indeed smelling the aromas as if they were in the studio.

Of course, the psychological process in this prank was the power of suggestion—the same principle that underlies successful hypnosis.

3. Ph.D.s Are Exempt From China’s One-Child Policy. On April Fool’s Day, 1993, a prominent Chinese newspaper announced an exception to the long-held state policy of allowing only one child per family. According to the report, all Ph.D.s were now exempt. Of course, it was a hoax. When the Chinese government found out, they condemned April Fool’s Day and its pranks as a dangerous Western tradition. Obviously, the Chinese government lacks a sense of humor.

2. UFO Lands Outside London. In 1989, thousands of motorists outside of London watched as a brightly glowing flying saucer descended and landed in a field. Police were alerted to a potential alien invasion and carefully approached the vessel. When a silver-suited figure emerged, one officer ran off in fear. The prankster was Virgin Records/Airlines head, Richard Branson, who had intended to land the craft (actually a hot air balloon) in London’s Hyde Park, but had been blown off course.

People are both fascinated with and fearful of the idea of aliens (and alien invasions). A majority of the public believes in extraterrestrial life, so well-done pranks involving aliens are particularly effective.

1. Dormant Volcano Erupts. I learned about my now-favorite prank on a tour of Sitka, Alaska. On April 1, 1974, a local practical joker (and helicopter pilot) flew hundreds of old tires to the crater of a nearby dormant volcano, Mount Edgecumbe, and set them on fire. The resulting smoke caused residents to believe the volcano was erupting.

Again, long-held fears are effective in pranking others. Classic April Fool’s jokes employed by elementary students—“There’s a spider in your hair!” Sneaking up on someone and yelling “boo!” and the like—often involve scaring someone.

What are your favorite April Fool’s pranks?

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