What are caresses for?

Numerous studies have highlighted the power of touch and its importance in human development and its psychological implications. In 1997, Mary Carslon and her husband, Felton Earls, published the results of a study revealing the developmental implications of the lack of physical contact they saw. Romanian children growing up in orphanage exposed: social withdrawal, lack of social expressions, lack of speech, and high levels of cortisol (known as the hormone of the stress).

Among some of the psychological consequences of the recent COVID-19 crisis, a condition has been described with the name of "skin hunger", which refers to the neurological manifestations in our body derived from the lack of touch due to the absence of physical contact during the pandemic, an intrinsic and natural need of all Humans.

The physical contact that is manifested through hugs, caresses or friction, is essential for our development and our socialization. In this article we will focus on the functions of caresses; its neural bases and its role in the field of health and in social bonds.

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How do caresses work?

Touch is the first of the senses that we develop when we are babies, and although perhaps if they made us choose it would be the The first one we would give up, this remains from an emotional point of view the most important during our entire life. life. Until recently, however, very little was known about how the sensory system worked.

The sensory system of the skin is unique, as it gives rise to different sensations, such as pain, itching, heat, vibrations, light pressure and light touch. Until a few years ago, we did not know how this system worked. A study conducted by Columbia University found that Merkel cells are the receptors for "soft" touch.

Merkel cells are responsible for fine motor skills, without them we would not be able to send an email or tie our shoes. Also, they help us detect the textures of objects, as well as a light hand pressure or a gentle caress.

But since Merkel cells are skin cells, not neurons, it was not clear how they could communicate with the nervous system. Thanks an experiment with mice norepinephrine was identified as the neurotransmitter responsible for transmitting the message; the neurons capture the neurotransmitters with beta-adrenergic receptors, which causes the neurons to send electrical signals to the brain and thus we can feel the touch.

If we think about it, touch is capable of detecting very small variations in the environment, we can know if a material is hot, cold, or warm. Apparently, some receptors would be specific to caresses, the tactile-C receptors. And by activating a specific part of the brain, a different sensation is created.

As we can see, although we are closer to understanding how the sensory system works, we are still far from knowing the complete path followed by caresses. how pleasurable information from touch is encoded and transmitted is still unknown.

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The importance of caresses in human beings.

But even if we don't understand the underlying mechanisms, what science has been able to show are the consequences of touch deprivation on development and social behavior. Highlighting its importance for the human being.

Stroking is necessary for development

Merkel cells may also play an important role in our cognitive development. Some studies have shown that newborns who are deprived of touch may have cognitive deficits that persist into adulthood. As information is not transmitted during the first years of life to the limbic system, responsible for the emotional response, and by not properly stimulating the brain during the first years of life, it will not develop in a healthy way.

The sensors begin to transmit information from the womb, therefore, a malfunction of the system during the development of the neurons can significantly affect what we know as the social brain, which refers to the ability that human beings have to relate to the rest of the world. people.

In addition, this malfunction also affects the development of the sense of self and independence, our sense of knowing who we are and what makes us different from the rest. This condition is typical of people with autism spectrum disorders. People with autism spectrum disorders have a deficiency in processing information that comes from emotional touch.

Babies do not have spoken language, the caress also plays a role as a primary form of communication and provides tranquility and well-being during the first months of life.

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Caresses and their relationship with stress

Apparently there is a type of excitatory neurons that would be involved in the sensation of pleasure that we feel when caressing or being caressed by other people. A study conducted at the University of Washington investigated the role of these neurons in suppress the expression of one of its receptors, specifically prokinectin receptor 2 (PROKR2).

The results showed that mice that had been genetically knocked out of prokinectin receptor 2 expression did not feel pleasure and did not respond to gentle stroking. However, these mice did feel other sensations related to touch, such as itching and pain.

In addition to not feeling pleasure, mice without the receptor showed poor responses to stress and asocial behaviors.

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Caresses allow us to express emotions

Researchers at the University of Berkeley, California, have shown that through touch you can transmit and recognize different sensations, highlighting their importance within the interactions social.

To prove their hypothesis, they did an experimental test where one subject stroked and another was stroked on the arm, the touch lasting only one second. Through the caress, the person in charge of playing had to try to transmit an emotion, within a wide range, it could be compassion, fear, anger, love, gratitude, etc. The person who received the caress had to try to guess which emotion from the list, it had been tried to transmit.

The results were quite surprising, as many subjects thought that they would not be able to recognize emotions through touch. However, more than 60% of the participants were able to discern when they had been caressed compassionate and more than half guessed when the other emotions were intended to be communicated: love, fear, anger or gratitude. Therefore, the study allowed us to establish that emotions can be transmitted through touch in a much more effective way than we think.

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Caresses strengthen bonds and community

A 2015 study asked its participants about the perceived sensation of stroking other people's skin, this one put It shows that people always think and feel the skin of others as softer, regardless of reality.

It also showed that caresses help strengthen social ties between people, since the more pleasure is perceived when being touched, the greater the affinity and affection felt for the person caresses

This kind of sensory falsity, in what we suppose the skin of the other, softer and warmer than it is, is common to all human beings and could be explained as a mechanism that fosters the relationship between human beings, and implies the creation of bonds of empathy and care between people, having as immediate consequences the sensation of well-being and security, to, in the long run, reinforce the union and the community.

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Caresses create a positive image of ourselves

Affective caresses are normally slow movements (between 1 cm and 10 cm per second) that occur between very close people (mothers and children, couples or the closest friends). These movements help with proprioception, which is the property that allows us to know at a precise moment where each body is. part of our body, but also with interoception, which are the signals that allow us to know our internal state.

This capacity of caresses was demonstrated thanks to the rubber hand experiment, where a person was able to detect the stimulation received in a hand holding a rubber hand over. This result revealed the ability of caresses to build an image that relates the psychological self and the corporeal self, producing a positive image of both, since the basis of caresses is affection and acceptance by others.

Stroking helps the immune system

The caresses not only have benefits on psychological health, numerous studies have shown the importance of touch: to help the system immune to fighting pain or favoring the overcoming of certain diseases, would also affect sleep, improving it and reducing pressure in the blood.

A 2020 study conducted by the American Psychiatric Association showed the relationship between caresses and oxytocin. Oxytocin is also known as the love hormone, which is released, among other times, massively during childbirth, and is closely related to loving behaviors between parents and children and between friends and couples. A group of researchers has recently revealed that this hormone would also be released when looking at our dogs or cats, enhancing the union with them.

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Other benefits of caresses

Apart from the benefits already mentioned, caresses would also have a role in other processes, including:

• Improved lung function
• Reduce the stress of childbirth in newborns
• Control of blood pressure and cardiovascular problems