Why can't I tickle myself?

This is a little off the beaten laughter path, but believe it or not, some research is being conducted in this area. In fact, researchers at the University of California in San Diego have even constructed a "tickle machine."

Some scientists believe that laughing caused by tickling is a built-in reflex. If this is true, then, theoretically, you should be able to tickle yourself. But you can't -- not even in the same area and the same way someone else tickles you into hysteria! The information sent to your spinal cord and brain should be exactly the same. But apparently, for tickling to work, the brain needs tension and surprise -- something that's obviously missing when you tickle yourself. How the brain uses this information about tension and surprise is still a mystery.

What's Funny?

­Laughter is triggered when we find something humorous. There are three traditional theories about what we find humorous:

  • The incongruity theory suggests that humor­ arises when logic and familiarity are replaced by things that don't normally go together. Researcher Thomas Veatch says a joke becomes funny when we expect one outcome and another happens. When a joke begins, our minds and bodies are already anticipating what's going to happen and how it's going to end. That anticipation takes the form of logical thought intertwined with emotion and is influenced by our past experiences and our thought processes. When the joke goes in an unexpected direction, our thoughts and emotions suddenly have to switch gears. We now have new emotions, backing up a different line of thought. In other words, we experience two sets of incompatible thoughts and emotions simultaneously. We experience this incongruity between the different parts of the joke as humorous.
  • The superiority theory comes into play when we laugh at jokes that focus on someone else's mistakes, stupidity or misfortune. We feel superior to this person, experience a certain detachment from the situation and so are able to laugh at it.
  • The relief theory is the basis for a device movie-makers have used effectively for a long time. In action films or thrillers where tension is high, the director uses comic relief at just the right times. He builds up the tension or suspense as much as possible and then breaks it down slightly with a side comment, enabling the viewer to relieve himself of pent-up emotion, just so the movie can build it up again! Similarly, an actual story or situation creates tension within us. As we try to cope with two sets of emotions and thoughts, we need a release and laughter is the way of cleansing our system of the built-up tension and incongruity. (According to Dr. Lisa Rosenberg, humor, especially dark humor, can help workers cope with stressful situations. "The act of producing humor, of making a joke, gives us a mental break and increases our objectivity in the face of overwhelming stress," she says.)

Next we'll learn why we don't all think that the same things are funny.