Where are you ticklish? Researchers map the sensation across cultures

Researchers have mapped the sensation of tickling across different cultures, revealing a consistent experience among humans regardless of their background. The study, published in Nature Human Behaviour, provides a foundation for standardized research into this unique sensation. Humans are not alone in their ability to experience tickling; other great apes, such as chimpanzees and bonobos, as well as rats and meerkats, also respond to tickling.

Gargalesis, the type of tickling used in the study, is associated with play and involves strong, repetitive pressure. This form of tickling often leads to laughter and squirming. In contrast, knismesis is a lighter touch that does not typically trigger laughter. While knismesis has garnered research interest due to its similarity to itching, a symptom of various medical conditions, gargalesis has been largely overlooked by scientists until now.

To explore the nuances of tickling, researchers from Radboud University in the Netherlands and Humboldt University in Berlin recruited 448 participants from Dutch, Greek, and Chinese cultures. Each participant completed a survey detailing their experiences and perceptions of tickling. They then used a computer to color in areas of a body model, creating maps of their ticklishness. This exercise was repeated for other body sensations, such as pain or pleasurable touch.

The survey results showed that 98.4% of participants had experienced tickling, and 95.8% had tickled another person. Notably, experiences were similar across all three cultural groups tested. This consistency might come as no surprise, as previous research has shown that interpretations of emotionally processed touch, such as hugging, can vary between cultures.

The findings of this study lay the groundwork for more systematic research into tickling, potentially shedding light on its evolutionary preservation and its role in human behavior.