eli5: why does tickling ourself not work but works when other people do it?

Question

eli5: why does tickling ourself not work but works when other people do it?

In: Biology

Answer 1

You can absolutely tickle yourself but when you do your brain is expecting it and prepares for it by dulling the signals. When someone else does it, even if you know it’s going to happen you reaction is more intense, which could also possibly be amplified by anticipation.