Why we get Ticklish and Laugh

I may not be a loud person for the most part and you'll rarely hear me raise my voice but, one of the few times that you see me do is when I'm being tickled. A poke on my sides will cause me to slightly jump with alert and probably let out a yelp. A tickle attack on me especially when I am trapped, will bring all the calmness into uncontrollable laughter, furious squirming and what feels like yelling STOP!! a hundred times but leads to about hundred more.

Why do we get ticklish in the first place?

Looking at the human brain, it makes you alert of being touched and of other matter of senses from millions of nerve endings in your body. There are two regions of the brain that creates a tickling sensation, the somatosensory cortex and the anterior cingulated cortex. Something like a touch will stimulate the nerve endings and sends signals to the brain, which it gets analyzed by the somatosensory cortex on things like how much pressure was applied. The signals also goes to the anterior cingulated cortex which deals with pleasant feelings. These two combined will lead to a tickling sensation.

Why you can't tickle yourself

You generally can't tickle yourself in the same manner as when it's done by someone else. On the back of your brain you have the cerebellum which deals with controlling movement. This part of the brain is able to predict that you're trying to tickle yourself where it will alert the rest of your brain that the action is taking place. This will largely mitigate the effect of the tickling sensation thus, you won't be able to tickle yourself. 

Some areas of the body are more ticklish than others which is due to them having more nerve receptors that are highly sensitive. This is especially evident in the soles of out feet. It can be noted that the areas that are ticklish are areas where it is uncommon to be touched by people.

Why do we laugh when tickled?

A simple touch by someone else on one of the many ticklish areas can cause you to giggle or laugh. Even when you have a sense that a finger is making its way to those areas you will have a smile on your face. Why is that so? Majority of the areas that are ticklish are areas where they are the most vulnerable to injury. It seems strange that you laugh when you are tickled doesn't it? This brings to a point that tickling is a creation of socialization. 

It may not be completely known as to why we laugh when tickled but, it is a way to show that you submit to an aggressor who's tickling you. The responses evoked by being tickled comes from humans growing and living in an acceptable social manner. This comes in the form of learning and teaching oneself to protect the vulnerable areas of the body. When you feel someone is about to put their finger to the side of your body, as a defense mechanism you draw your arm in to shield that area. (source:Clark) 

The involuntary laughter from tickling is a way of not being harmful to the tickler, the aggressor, in a playful manner. That is, until the tickler goes too far with the unwanted tickling, is where negative reaction can occur. Tickling can stimulate nerve fibers that causes pain so, over tickling or tickling too hard can be painful. (source:nye) Playful tickling can be a great fun way for individuals to interact, from parents bonding with their children, from friends that is likely to be more in a torturous manner as well as with lovers but, will likely lead to something else.

A little unwanted tickling is fine with me, it's all fun and games. If you decide to proceed further with it though, just take note that my arms, elbows and legs will be flailing around frantically out of control laughing hysterically. It's not always safe for all you ticklers.