Why are we Ticklish?

The video explores the concept of tickling, dividing it into two types: nysmesis and gargalesis. Nysmesis is the itchy sensation caused by light touches, while gargalesis involves a mix of pain and pleasure from harder touches, primarily affecting primates. The video suggests that gargalesis may serve an evolutionary purpose, helping young primates learn self-defense. Tickling induces laughter and positive expressions, encouraging interaction and learning.

What are the common vulnerable areas of the body where gargalesis is experienced?

How do humans and primates react to tickling, and what does this reaction signify?