You may remember being tickled as a kid on some part of your body where you laughed so hard it hurt. You may also have begged your tickler to stop in between gasps. This kind of tickling that almost borders on pain is called gargalesis.
In general there are two types of tickling, knismesis and gargalesis. Knismesis refers to a light tickling sensation caused by soft stimulation to an area of the body in people as well as many other animals. For example running your fingers down the back of a person’s neck would be a form of knismesis that could be very relaxing or entrancing for some or make others shiver. Knismesis also can be a creepy crawly feeling such as when you have a small insect tickling your arm.
In contrast gargalesis is the result of heavy stimulation usually to specific parts of one’s body, commonly the underarm area, feet or stomach. This king of tickling involves poking the part of the body or rapidly stimulating the area with one or more fingers with a relative amount of pressure. In addition, ticklish spots can very from person to person but almost everybody has experienced gargalesis; however, some people can train themselves to be immune. Gargalesis can not be done to oneself and must be initiated by another person or thing.
The strange thing about gargalesis is that despite its temporary unpleasantness, it results in smiles and laughter. One theory set forth by Christine Harris, a researcher who studies tickling, speculates that gargalesis serves the adaptive purpose of learning survival skills especially combat. Because gargalesis triggers the one being tickled to physically respond or attempt to get away paired with its laughter and game qualities, it could be viewed as a fun learning lesson. Harris thinks that the happy facial expressions and giggling signal to the person doing the gargalesis that the other is enjoying it. In other words, if gargalesis was met with fear and crying people would be less likely to engage in the tickling and not learn survival skills.
Although it may be funny when you are the one causing gargalesis, doctors recommend that people don’t do this to others for an extended period of time especially children. Gargalesis can potentially be dangerous causing neck and other injuries. In addition, despite laughter, rough tickling can cause a child emotional distress when their pleas to stop are covered up with laughter. That’s why a lot of kids refer to this game as tickle torture.
