When is a prank or a joke funny? A prank is all about expectation versus reality, and the moment of surprise that follows. Here are the characteristics of some types of pranks:

A big gap between an expectation and the reality, with an initial disappointment or fear

For this type of prank to be effective, there has to be a big gap between an expectation and the reality. It also has to be something so unexpected, so widely remote, that it becomes funny. And it must include an element of initial disappointment or fear.

For example, a coffee cup spilled on company papers that you’ve spent hours preparing and that are ready to be sent to your clients is something very close to a disaster. Then, in the moment when you find out that the spilled coffee and cup is fake, you feel a huge relief as your brain realises that you don’t need to reprint all 100 pages. This microsecond moment between disappointment and relief, this very thin barrier, triggers the moment of surprise, which is funny. It’s funny for the prankster and his or her audience, and/or eventually it’s even funny for the person who was pranked.

This is the cycle of this first type of prank. The fake spilled coffee cup has a moment of expectation (spilled coffee on my papers is bad), uncovered reality (it is fake, not extra work for me, thank God) and the moment of surprise in between. More examples from this category are in the videos below: a nail through the bleeding finger, a severed finger from the mouse trap, a snake jumping out of the box, fake rattlesnake eggs in the envelope, and a fake spider in the box.

It is important to realize that the time factor is crucial here. If the moment of realization about what’s happening is too long, or the joke or prank is too complicated to understand, it is not funny. Then it just becomes embarrassing.

Each time a prankster attempts to prank somebody, they put themselves at risk of being embarrassed. This is the adrenaline which drives the pranksters.

A big gap between an expectation and the reality, involving an unreasonable or bizarre element

The initial disappointment or fear does not need to be present in order for a joke or prank to be funny. In this second type of prank, disappointment or fear can be replaced by something unreasonable or bizarre. All of us expect a toothbrush to be a certain size. If it’s ten times bigger, it is so bizarre that many people may find it funny. The giant toothbrush is funny because it is not a toothbrush any more. It won’t fit in anyone’s mouth, it has no practical use, it doesn’t serve the purpose—so it is bizarre. There is an expectation (normal toothbrush) and the reality (a toothbrush ten times bigger), and also the moment of surprise (you’re seeing it for the first time in your life).

The unreasonable or bizarre element has to be something you haven’t seen before: that’s why it is funny. More examples from this category are in the videos below: fake soft bricks, power outlet stickers, fake cat voice, fake bitcoin and money, and fake gift boxes with displayed content that does not exist.

Reaction of the pranked person

The reaction of a pranked person depends on his or her personality, his or her relationship to the prankster, and the immediate situation:

  • The prank might trigger a laugh, which is gives the prankster a moment of satisfaction. People with self-confidence, who have a friendly relationship with the prankster and are in an appropriate situation, will usually laugh.
  • The pranked person might get angry. This is the risk of pranking somebody. Anger might follow if the pranked person is in a superior position to the prankster, e.g., his or her boss, a colleague with higher seniority, a parent, etc. Anger may also be triggered in an inappropriate situation, when the prank is not welcome.
  • A third possible reaction is a shame or crying. This reaction happens if the pranked person has zero sense of humor or is in an inferior position to the prankster, e.g., a colleague with much lower seniority, a child versus a parent, an older sibling versus a younger sibling, etc. Shame or crying might also be triggered in an inappropriate situation.

The inappropriate situation related to all three examples above are, for example, if the pranked person is in a bad mood, if he or she is too busy or stressed, or if too many people are watching and he or she feels embarrassed. For example, one of the most inappropriate settings for pranks is a funeral.

Pranksters put themselves at risk every time they attempt to prank somebody. They risk embarrassment, shame, anger, or crying. But in most situations, pranks make our lives more colorful and funny, and enlighten many otherwise boring situations.