Tickles

Tickles are a sensation caused by light touching or stroking of the skin. This sensation typically elicits involuntary laughter or other physical reactions. There are two main types of tickling: knismesis and gargalesis. Knismesis is a light, feathery touch that may cause a tickling sensation but rarely results in laughter. Gargalesis is a more vigorous tickling that typically provokes laughter and a squirming reaction.

The exact neurological basis of tickling is not fully understood, but it is thought to involve the activation of specific nerve endings in the skin. These nerve endings send signals to the brain, which interprets them as a tickle. The brain's response to tickling is complex and involves areas associated with pleasure, pain, and social interaction. While tickling is often associated with play and affection, it can also be used as a form of mild torture. The sensation can be amplified when the tickled area is particularly sensitive.

Humans are not the only species that experience tickling. Some primates, such as chimpanzees and gorillas, also exhibit tickling behaviors and vocalizations. Research suggests that tickling may play a role in social bonding and the development of communication skills, particularly in young individuals. The individual's expectation of being tickled can also influence their reaction, with unexpected tickles often eliciting a stronger response. The sensitivity to tickling can vary greatly from person to person.