Whether it’s chalk squeaking on a chalkboard, fingernails scraping across Styrofoam, or a fork sliding across a plate, there are sounds that make most people cringe and feel an icy shiver down the back of their neck. The sound is perceived as unbearable, the hairs on your back stand up and goose bumps appear on your arms. But why do we actually get frightened by such harmless noises? And where does the shiver on the back of the neck come from?
Goosebumps as a reaction to noise
This reaction is a relic from prehistoric times that is innate to most mammals. A loud, shrill noise usually meant danger in the past. And to protect themselves from it, body hairs automatically stood up to make the body seem larger and more threatening, putting the attacker to flight.
This reaction is controlled by the limbic system, which is responsible for processing emotions in the brain. It is directly connected to the nerves, which in turn are responsible for the erection of the hair. Although humans no longer have fur today, the remaining fine body hairs still stand up in response to unpleasant noises, thus causing goose bumps. This actually causes the feeling of a cold shiver running down the spine.
Reaction to squeaky chalk varies
In the animal world, this protective mechanism may be essential for survival – but in humans, it has now become superfluous. Nevertheless, there is nothing that can be done about this reaction.
It is noteworthy, however, that not all people are sensitive to the same sounds. While some wince at the squeak of chalk, the sound of filing fingernails makes others cringe.
Sequence of individual experiences
Scientists suspect that this is related to the experiences a person has had over the course of his or her life. For example, the squeak of chalk may be associated with a nasty teacher at school, the scratching of a fork on a plate with a parent’s instruction to finish eating.
These unpleasant experiences are stored in the limbic system and henceforth associated with the sounds. This is why young children rarely show such reactions to certain sounds, because they usually do not yet have so many experiences stored in the limbic system.
