Whether chalking squeaks on a board, scraping fingernails over polystyrene, or slipping a fork over the plate, there are sounds that make most people wince and feel an icy chill on their necks. The sound is perceived as unbearable, the hair on the back stand up and goose bumps on the arms. But why are we really scared of such harmless noises? And where does the chill come from?
Goose bumps in response to noise
This reaction is a Relic from prehistoric times, that is innate to most mammals. A loud, high-pitched noise used to mean danger in the past. And in order to protect themselves from this, the body hair automatically set up to make the body seem larger and more threatening and so to beat the attacker to flight.
This reaction is controlled by the limbic system, which is responsible for the processing of emotions in the brain. It is directly connected to the nerves, which in turn are responsible for setting up the hair. Although humans today no longer have fur, the unpleasant noises still create the remaining fine body hair and thus provide goose bumps. This actually leads to the feeling that a cold shower would run down the back.
Reaction to creaking chalk different
In the animal world, this protective mechanism may be vital - but in humans it has become superfluous. Nevertheless, one can do nothing against this reaction.
It is noteworthy, however, that not all people are sensitive to the same sounds. While some wince at the chalk squeal, others make the sound of filing fingernails shudder.
Sequence of individual experiences
Scientists suspect that this is related to the experiences a person has accumulated in the course of his life. So the squeaking of the chalk may be linked to a nasty teacher at school, the scratching of the fork on the plate with the parents' requirement to eat the food.
These unpleasant experiences are stored in the limbic system and connected with the sounds from then on. Therefore, even small children rarely show such reactions to certain sounds, because they have not usually stored so much experience in the limbic system.