I still remember I used to do this a lot to my younger brother during our childhood whenever I had to make him laugh and he used to burst into laughter like anything. However, I never gave a thought to the question.... Why does it happen when someone touches our sensitive parts like neck, tummy, armpits, soles. etc? Interestingly, many people do not like tickling but they do laugh when it’s done. So, what is it that makes us laugh?
According to scientists, we laugh when the aforementioned parts are tickled due to our body’s defensive mechanism. According to researchers, we get signals like yielding an attacker during tickling. By doing so, this mechanism reduces the state of stress and saves us from getting hurt.
The reason for this is our brain’s back part, which is called cerebellum. It tells us that we are going to tickle ourselves; therefore the brain does not send signals when such efforts are made. Evolutionary Biologist and Neuroscientists concur, on tickling, the same part of the brain (hypothalamus) forces us to laugh, which is active before painful sensations.