Why does the skin wrinkle in the water?

The reasons why skin wrinkles in water remain unknown to science. Currently, there are several theories and the most recent one may be very revolutionary.

Last update: August 26, 2021

We have all seen skin wrinkle in water after a few minutes of being in contact with the liquid. However, this does not occur in the whole body, but only on the palms and fingers, and on the soles of the feet. Why does this happen?

As we will see later, several theories have been put forward in this regard. In the first instance, the idea has been postulated that the outermost part of the skin swells when it absorbs water. The result is that the skin is wrinkled.

According to the traditional explanation, the skin wrinkles because this is a mechanism to compensate for the increase in area. In this way, the skin absorbs water, swells, the area grows and wrinkles balance the increase in volume. However, in the face of this there are great debates due to different findings.

What was believed before?

Why skin wrinkles in water is a mystery to science.

The reasons why skin wrinkles in water are a mystery that does not finish deciphering. The question is old, and although this reaction has no relevant implications, the truth is that it has raised interesting controversies.

The traditional thesis speaks of the absorption of water through the outermost layer of the skin, or epidermis. The function of this is to prevent the water from evaporating from the body and to protect the innermost layers from possible damage.. The outermost layer of the epidermis is called the stratum corneum.

In the stratum corneum there are keratin cells that would be the ones that absorb water and cause swelling. But since the epidermis is attached very firmly, wrinkles occur to compensate for that excess volume in the area.

The question arises: why does this only occur in some areas of the body and not in others? The answer would be that hands and the feet have a thicker layer of keratin cells. Therefore, only in these areas does the skin wrinkle in the water.

What do you think today about why skin wrinkles in water?

For a long time the above explanation was accepted. However, everything began to change in the 1930s. Scientists discovered that whether people had nerve damage to the fingers, then the effect did not occur of wrinkles.

This led to the theory that if the skin wrinkles in water it is due to an involuntary reaction of the autonomic nervous system. It is believed that contact with the liquid activates the sympathetic nerve. This, in turn, causes the blood vessels they contract. The result is that folds or wrinkles are formed.

These explanations took a new turn thanks to the intervention of neurobiologist Mark Changizi from the artificial intelligence research institute 2AI Labs. In 2011 he proposed a new theory that has been gaining strength.

Changizi argues that the skin wrinkles in the water as an effect of an evolutionary adaptation. The function of these wrinkles would be to improve the grip of wet or submerged objects. On the soles of the feet, they would also protect from slipping on wet surfaces.



How has this theory been proven?

The wrinkles in the skin would be an adaptation to be able to catch elements without them slipping, although the theory has not been 100% proven.

Mark Changizi's theory indicates that wrinkles work as a drainage system. This was corroborated with the analysis of photographs of 28 human fingers. In them you can see an area of ​​bulging skin, separated by channels that are not connected to each other.

In Changizi's opinion, such channels have the function of expelling water and improving grip. He also found that the skin wrinkles in the water only after five minutes of contact with the liquid. And that this happens much faster in fresh water than in salt water.

To corroborate the theory, a study was carried out in which a group of volunteers were asked to take different types of small objects with smooth and wrinkled hands. The results showed that the grip was stronger when the skin is wrinkled in the water.

However, another study published in 2014 in Plos One came to the opposite conclusion. Experts from a 2020 investigation, not yet certified by peers, comes to the same results as Mark Changizi. Definitely, there is evidence for the thesis, but it is not conclusive.



So why does the skin wrinkle in the water?

Mark Changizi thinks that the difference in the results of the studies is due to the fact that this evolutionary adaptation did not occur just because, but because the skin wrinkles in the water to support the support of the own body weight, not to hold small objects in your hands.

Therefore, this function should be tested in situations such as handling heavy objects or grasping trees. In the laboratory and with the observation of the manipulation of small objects it is difficult to prove the thesis. The debate is still open.