Why does the skin get gooseflesh?

Goose bumps are one of those phenomena that remind us that the separation between humans and other animals is, deep down, a mirage, something artificial. Our body is constantly traversed by hundreds of physiological processes that regulate the way we react to our environment, in theory to better adapt to its variations.

However... In the case at hand,Why does the skin get gooseflesh And how does this relate to our emotions? Let's see.

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What is goose bumps?

A summary definition of what is goosebumps is the following: it is a condition of the skin in which the body hair remains bristly, so that as this hair is very fine and short in human beings, it seems that tiny "mountains" appear on the surface of is. The hairs stand on end, but we usually pay more attention to the part of the skin that forms the basis of these.

The straightening of skin hair, known as piloerection in more formal or scientific contexts, is carried out by small muscle fibers linked to the base of each of the hairs.

In addition, this phenomenon does not usually occur in isolation, but is related to changes in states of consciousness and, specifically, in emotional states. In this way, goose bumps have a physiological dimension and another psychological dimension related to emotions. Below we will explore in a little more detail what we know about each of these two facets of having the creeps.

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The physiological mechanisms of piloerection

It is known that the phenomenon of goosebumps, also known as horrifying, is a vestigial reflex that usually has an adaptive function in mammals in general, since this group of animals are characterized by having hair.

The mechanism by which these bumps appear on the skin for a short period of time is as follows.

1. Activation of the sympathetic nervous system

This part of the nervous system is the circuit of nerve cells that intervenes when certain environmental stimuli make us react to the environment in a more intense state of activation than normal. For example, it is the type of contexts in which they are usually activated attack or flight behavior patterns.

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2. Stimulation of the piloerector muscles

These tiny muscle fibers are connected to the sympathetic nervous system and act as a bridge between the latter and the hair follicle, where they are attached. Upon receiving a signal from one of the nerves, these smooth muscle fibers contract pulling the hair upward.

3. Hair shaft change

In the normal state, by default, the body hair is arranged obliquely. That is, falling on one side, instead of being perpendicular to the skin. When it is tightened by the piloerector muscle, the trajectory of the hair shaft begins to straighten, so that instead of being almost close to the skin, it is pointed. The tension that is generated between the skin that surrounds the base of the hair, on the one hand, and the fibers Muscle muscles, on the other hand, cause a bump to appear on the part of the skin where it protrudes each hair.

Why We Get Goosebumps: Evolutionary Functions

As we have seen, goose bumps are something related to the vestigial reflections that come to us through a line ancestors who did not belong to our species and who probably had body hair much more developed than U.S. Thus, the piloerection could be the difference between having more or less offspring, or between surviving or not. Specifically, it has been an advantage for the following reasons

1. Helps to insulate from the cold

Piloerection appears among other situations when the body is exposed to cold, so makes body hair fluffier and creates a wider insulating layer between the skin and the environment. In this way, body heat is better conserved.

2. It is associated with situations of danger and reproduction

Another use of goose bumps, at least in our ancestors and in the rest of mammals characterized by having hair denser and thicker body, is to facilitate the body a way to appear larger, which is useful in case they are around close other potentially dangerous animals that may become doubtful about whether to attack or not.

At a level of social adaptation, furthermore, bristling hair is a quick way to make others notice that there is a danger nearby as it affects the whole body and as long as you look in that direction it is easy to watch.

On the other hand, sexual arousal is also capable of producing bristling hair, which can be associated with the need to communicate interest or to signal a certain status. The latter is something that in mammals is closely linked to reproduction, especially in the case of males.

The case of the human being

In the case of humans, the range of sensations that we can have is more varied than that of most mammals, since our mental processes are very enriched from contextual information articulated from abstract thought.

For this reason, goose bumps can appear in many situations in which a very intense emotion invades us, such as listening to music, being touched by a person, or even listening to a speech or reading a book. In this case, the evolutionary utility loses its relevance: the bristling hair does not have a specific function, it simply exists as a consequence of a process of natural evolution that has led to us (in the case of our line evolutionary).