Tickling is bad for you in some cases, especially when it's overdone as it can also lead to negative physical effects and psychological effects and can overwhelm your nervous system and make you feel helpless and even trigger your fight or flight response.
In some cases of tickling it could be a form of abuse and could cause physical harm.
Tickling is also bad for babies who cannot consent to the tickle.
Tickling also stimulates pain receptors even when the person is laughing and for some people, especially in children, the excessive tickling can cause difficulties in breathing or exacerbate asthma symptoms.
And forceful or repeated tickling of someone in sensitive areas can cause pain and even trauma, and extreme or relentless tickling can be a form of torture and has been a form of torture and can cause hypoxia which is a lack of oxygen to the brain.
Tickling someone can also lead to uncontrollable laughter and a loss of physical control, which can also be distressing and or humiliating for some people.
Tickling is both mental and physical although being ticklish is mainly a physical reaction to touch.
Although how you perceive and react to the tickling is also influenced by your mental state and your past experiences.
The ticklishness is triggered by nerve receptors in your skin which are sensitive to light and touch.
And the hypothalamus which is a part of the brain involved in emotions and the fight or flight response is activated when you're being tickled.
The tickling sensations are processed by the brain as a combination of touch and pleasure and involves the somatosensory cortex and the anterior cingulate cortex.
The somatosensory cortex is what processes the physical sensation of touch and the anterior cingulate cortex is what interprets it as being a potentially playful and positive experience.
The cerebellum also plays a role in predicting and even potentially inhibiting or preventing the tickling sensation, which is why we cannot tickle ourselves.
The reason why you cannot always tickle yourself is because your brain knows to expect the tickle and so it doesn't allow you to feel the tickle when you've done so yourself.
Basically when you move your own hand to tickle yourself, your cerebellum anticipates the touch of the tickle and the resulting sensation.
The part of the brain that does not allow you to tickle yourself is your cerebellum.
The cerebellum is located at the back of your brain and is the primary brain region which is responsible for preventing you from tickling yourself.
The cerebellum monitors your movements and predicts any sensory consequences of your actions.
And by doing so it cancels out the tickle sensation when you initiate the tickle yourself.
Your brain knows to expect the tickle and so it doesn't allow you to feel the tickle when you've done so yourself.
Basically when you move your own hand to tickle yourself, your cerebellum anticipates the touch of the tickle and the resulting sensation.
The prediction of the tickle allows your brain to suppress the tickle response which makes the tickle sensation less intense or even absence.
Your cerebellum distinguishes between external touch such as when someone else tickles you and the self generated touch is prevented when tickling yourself.
Also the somatosensory cortex that processes touch and other sensory information, is also involved in the tickle response although it's activity is reduced when the cerebellum predicts a touch that is self generated.
The ticklishness is also influenced by factors such as context and mood, with situations of fear or anxiety being able to suppressing the tickle response.