The kiss, that act of pressing one’s lips against the surface of another’s as a sign of affection, affection or desire, is a very widespread expression in modern society. If we reflect on this emotional demonstration beyond its psychological meaning, we find ourselves faced with a custom that can be counterintuitively harmful, as we will see in later lines.
The act of kissing can contain around 80 million bacteria that are transmitted to the recipient, and not all of them necessarily have to be good. Any pathogen found in saliva can be transmitted by this affection mechanism, whether it is a virus, bacteria, fungus or other small enough parasite.
It is for this reason that, if we apply common sense, we have to ask ourselves: What is the evolution of kisses? What evolutionary meaning does a behavior have that can endanger the survival of the person who performs it? How did the kisses come about?
As you can see, an act apparently so simple and devoid of biological meaning (although loaded with emotional meaning) contains a series of unknowns to be resolved. Immerse yourself with us in the world of kisses, not from a romantic but a biological point of view, because the reflections that arise will surprise you.
The evolution of kisses: from the biological to the romantic
The first answer necessary to chain the rest of the relevant questions is, indeed, to discover the origin of the kiss. The first record of a kiss-like behavior that we know today is found in the Vedas, ancient texts of Indian literature that laid the foundations of the Vedic religion (prior to Hinduism). Thus, this first evidence dates back 3,500 years.
Furthermore, civilizations as ancient as the Sumerians already created poems in which the presence of the kiss was evident as an act of affection and romanticism. We are not going to continue citing historical examples, since the concept we want to convey is clear: the kiss has accompanied humans for many, many years.
What does draw more attention (and is certainly more difficult to explain) is trying to answer this question: why did the kiss arise? There are different theories that explore a possible answer and we show them to you below.
Do we learn to kiss or is it part of our genetic code?
The first consideration to take into account in this area is to know if the kiss is a learned act or based on the most primary instinct of the human being. Unfortunately, we don’t have a clear answer, but there has certainly been speculation about it.
In favor of the theory that maintains that This display of affection is instinctive, we find different evidence: For example, behaviors similar to kissing are widespread in the animal kingdom, whether through the rubbing of beaks in birds, licking in dogs or contact between antennae in insects. Anyway, we also found an animal that kisses exactly like us: the bonobo.
Bonobos exchange saliva in multiple situations, as they use kissing to calm tension after fights over hierarchy, to comfort each other, in order to strengthen relationships in the group or, simply, for no apparent reason. This is not entirely surprising, since we share 98.7% of our DNA with these primates, which certainly explains why certain behaviors are so similar between both species.
In any case, the evolutionary concept of the “kiss” is something that is often mistakenly attributed beyond the group of primates (or birds, perhaps). Can we conceive antennal play between insects as an act of affection? Unfortunately, there is not enough evidence to attribute such meaning to it. Yes, it can be used for recognition between conspecifics and to provide certain information from the male to the female before reproduction, but from there to affection or affection… there is a long way to go.
On the other hand, there are some arguments that weaken the theory that the act of kissing is an inherited behavior. 90% of cultures kiss (although not all of them romantically, as we will see below), but the remaining percentage does not How can we explain that these individuals do not kiss if it is something genetic and ingrained in our entire species?
We kiss out of passion, romanticism, affection, affection, etc. All these psychological impulses are more than described, but we are not referring to that. Why do we kiss like animals? What primitive evolutionary explanation does this behavior have? Again, there are various theories in this regard and none have been completely confirmed.
According to various researchers, the act of kissing may have evolved in humans due to previous behavior of regurgitating food mouth to mouth from mothers to children, a form of parental care relatively widespread in the animal world (especially mammals and birds). Since we do not want to make any reader nauseous, we will limit ourselves to saying that the most passionate kiss (French) and the regurgitation behavior share quite similar mechanisms.
On the other hand, it has been postulated that the kiss responds to a clear mechanism of sexual selection From a biological point of view, when we approach the face of another human being, we obtain a very valuable amount of information (even if it is subconscious). For example, studies have discovered that certain sample groups of women feel more biologically attracted to men with pheromones that show that their genetic profile is distant: let’s explain.
From an evolutionary point of view, reproduction between relatives is deleterious for any species, as it reduces the genetic variability of the population and therefore makes it more vulnerable to possible environmental changes. Pheromones can inform the two components of a couple (to a certain extent) how genetically related they are, in order to avoid reproducing if they are related and give rise to offspring with less variability. Of course, these assumptions must be taken with a grain of salt, since the experiments are carried out in laboratory environments and the social component is not taken into account.
In addition to a concept as abstract as pheromones, there are other much more obvious mechanisms. For example, Bad breath is usually a sign of an underlying disease or pathology Getting close to the face of a potential partner allows us to suspect their state of health, and therefore, the quality of their genes.
Until recently, it has been repeatedly repeated in the media that the kiss is present in 90% of cultures. This is half true and half false, since a study published in 2015 showed that Kissing as a romantic act is only present in 46% of the cultures sampled
Yes, the majority of individuals on the planet kiss (for example a mother with a child), but less than half of us do it with sexual intention. This, of course, calls into question once again the theory that kissing as we know it from the West is a behavior engrained in the human genome.
Other considerations
In addition to providing biological evidence of the individual we kiss, not everything is based on a set of genetic benefits. Kissing also promotes the release of oxytocin, dopamine and endorphins essential neurotransmitters in the feeling of pleasure and well-being.
Furthermore, it has been shown that in relationships, an increase in the frequency of kisses reduces stress levels, strengthens the bond and even translates into a reduction in blood cholesterol levels. Therefore, in addition to its subjective emotional component, kissing has a clear physiological benefit: improving the well-being of the individual.
Summary
As we have seen, the evolution of kisses is a topic that moves between gray scales and never in absolute statements. The evolutionary origin of kisses itself is in a field of constant speculation, since We are not even clear if kissing is a behavior engrained in the genome of our species or if it is a trait acquired through learning.
In any case, one thing is clear: despite the diseases that can be transmitted through it, the kiss provides much more positive than negative. Illnesses come and go quickly, while maternal affection, the building of an emotional bond, affection and love are much more permanent concepts over time.
