There are various types of kisses, friendly, romantic, informal, etc., and the kiss is one of the human behaviors that do not seem to have scientific explanations simple. Perhaps the reason is that a kiss means so many things, love, sweetheart, farewell (for example, kissing the air when a person), among many others.
And is that a kiss is more than a kiss. According to the filematologistas, the scientists who study this matter of kissing, it is not clear why humans began to piece together their lips with those of another person in the first place. The most accepted theory is that this comes from the primates, as when, for example, the mother ape would chew the food for the ape small that still have no teeth, and passes the food to your mouth directly. The contact of the lips may be part of evolution and not necessarily a way to survive, because in general it is considered that kissing generates social bonds and expressions of love.
Today it is thought that kissing helps transfer critical information. Kisses are associated with the courtship romantic that can help us to choose a good mate, send chemical signals and building in any way long-term relationships. All of this seems to be part of the ultimate goal of evolution, procreation successful.
Kissing allows you to get closer to the couple in order to “measure” (probably not consciously), the essential features on the same. Part of the exchange of information seems to be facilitated by pheromones, chemical signals that are passed between animals to help send messages. We know for a fact that animals use pheromones to alert their relatives about the presence of other animals, sources of food and danger, and the researchers make hypotheses about the role they can play these pheromones in behavior between humans.
There are studies that indicate that chemical signals play a role in attraction among humans. A study conducted by Claud Wedekind about 10 years ago, concludes this. In this study, women smell the shirts of men and indicated which ones they smelled better. By comparing the DNA of the man and woman, the researchers found that women do not choose the masculine essence of haphazardly. Is known as you prefer the smell of a man that is more suitable to the complex histocompatible (MHC) -a series of genes involved with the immune system. Have a MHC different is less likely to be healthy and have a normal life. Kissing can be a subtle way for women to measure this support immune of the couple before you invest too much time and energy in the same. Maybe a bad kiss means a lot more than we think, it could mean what is commonly called “no chemistry”.
Behavioral research supports this reasoning biological. In 2007, researchers at the University of Albania study of 1041 students and found significant differences in how men and women perceive kissing. Although this behavior is common in the courtship loving, women put more importance on kissing, and the majority said not to have sex without before not having kissed your partner. Men, on the other hand, they could have without more ado sex without kissing before and even do not have difficulties in having sexual intercourse with a partner who simply does not know how to kiss properly. But as women -in many species – are the ones who choose the partner, this behavior makes sense.
It should be noted that it is more frequent that the men kissed more in the French style, and the researchers believe that this is because saliva contains testosterone, which increases libido. The researchers also think that men might be able to choose to women with certain levels of estrogen, which is a predictor of fertility.
But since then the kissing, beyond these investigations, it is something that makes us feel good. This makes the kissing is releasing some chemicals that reduce stress and increase social ties. The researcher Wendy Hill, and her colleagues in the College of Lafayette measured the levels of oxytocin, which involves the link between couples, as well as the level of cortisol, a hormone associated with stress, which changes when the people kiss. Using a small sample of couples in college who were already in a long-term relationship, the cortisol levels dropped after kissing. The longer a relationship has the couple, the more it decreases the level of cortisol. We can say that the levels of cortisol also decrementaron in the control group, where the couples, simply by holding hands, they achieved this effect indiciando that the social bond can generate lower levels of stress, which not only succeeds in kissing.
With regard to oxytocin, the researchers found that it increases only in men, contradicting the initial assumption that this was the case with both sexes. It was concluded that it could be that women had more need of kissing to stimulate the nexus and the emotional bonds with your partner. Another possibility that were indicated by the researchers is that the sterile environment of the research laboratory was not conducive to creating a feeling of unity among people.
So, then, kissing is not only jea a role in the find and/or select couple, but it is useful to create links. At a meeting of the Association for the Advancement of Science, on the topic of the science of kissing, Helen Fischer, a biologist, evolutionist, gave their reasons to explain why we bring together the lips with other people. She thinks that the kiss imvolucra three main types of attraction among humans: the topic of sexual relations, which is governed basically by testosterone; romantic love, which seems to be regulated by dopamine to a greater degree; and the affective bonding, which involves elements such as oxytocin. Kissing, since it postulates the biologist, for help on all three fronts. The saliva that is exchanged in the romantic kisses, has testosterone. The chemicals are distributed when we kiss, that helps to fuel the romance. And the kiss finally allows you to release chemicals that produce emotional bonds, which can lead to the involvement of the couples in the longer term.
It is interesting to know that not all mammals share a kiss. Some mammals have close contact with their faces to each other, but licking each other, rubbing and their sense of smell, which also conveyed information. And although moms chimpanzees can pass on to their babies, the food mouth-to-mouth, this doesn’t seem to mean anything more. For example, bonobos are a species notoriously promiscuous which seems to be yes kiss really. And even though 90% of the human population kisses, there is a 10% that does not. So, not everything is solved by science in this sense.
It has also been studied as the people you kisses. There are societies in where they give two kisses, one on each cheek, for example, while in other societies it is a single kiss. In a study published in 2003 in the journal Nature, found that the double of the adults against the same number of women, turn the head to the right when kissing. This behavior asymmetric seeks to be explained from the last weeks of pregnancy or in childhood. Perhaps, not what the study says, is simply a learned behavior.
But the best part of kissing is to not think in any of this of what we talked about. Just close your eyes, kiss him and let Nature take its course.