Question

Why do we laugh when we get tickled?Give a valid reason.

Answer 1

Science’s greatest mind like Charles Darwin, Galileo, Francis Bacon even Plato found this mystery very challenging. But there is one thing for sure: It’s NOT because we find it funny. There are many people who find tickling unpleasant and there are some who won’t feel a thing. So what’s the science behind it?

There are two kinds of tickling phenomena:
Gargalesis: It is the heavy tickling that produces laughter, especially when targeted at sensitive areas like armpits and stomach.
Knismesis: This is caused by light movements and tends to elicit an itching sensation rather than a laughter.

When we are touched, the nerve endings under the top layer of our skin called epidermis, sends electrical signals to the brain. The effect of being touched resulting in a tickling sensation is the result of of the analysis of two regions of the brain. The somatosensory cortex is responsible for analyzing touch. The signal sent from the skin's sensory receptors also passes through the anterior cingulated cortex, which is involved in creating pleasurable feelings.

Evolutionary biologists and neuroscientists say that we laugh when tickled because the part of the brain that tells us to laugh when we experience a light touch, the hypothalamus, is also the same part that tells us to expect a painful sensation. Laughing when tickled in our sensitive spots (under our arms, near the throat and under our feet) could be a defensive mechanism. Research suggests that we have evolved to send this signal out to show our submission to an aggressor, to dispel a tense situation and prevent us from getting hurt. You also can’t tickle yourself because your brain knows it’s coming.

Fun Fact: Gorillas and rats laugh like us when tickled.