system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is that spot between the bottom of your ribs and your hip bone so ticklish for so many people?

A light pinch there could take down a grown man in some circumstances. I feel like it's a super power of some sort but I am immune to the tickle.
gpt
Well some people believe that the sensation of tickling evolved as a method for young children to learn how to defend themselves from predators (especially in prehistoric times). Consider this, someone tickles you and your first response is to cover it up or in some other way try to defend the area. Your brain then rewards you for your learning with laughter or more chemically a dopamine release. Areas like your side that are "excessively" ticklish are just areas of the body that are particularly vulnerable. That gap in your ribcage has to be there for movement purposes, but is no where near as safe as your ribcage. Your body is emphasizing the need to protect that area because if a tiger got his teeth around it, or any other nasty creature, it would be a very easy kill for the tiger.