Monogamy and infidelity: are we made to live as a couple?

We are talking about one of the favorite topics in the world: the infidelity. Adultery has traditionally been viewed as some kind of mistake against nature, some kind of set of little cracks in the surface of what human behavior should be. Thus, the concept of an “extramarital affair” has been associated with a failure of people to appease their impulses and form a family.

In general, infidelities were considered an exception, which does not represent the human essence. However, one should ask whether this approach is realistic. Have you ever wondered if there is a mechanism in our brain that directs us to the monogamy?

The quick answer to this question is: no, there isn’t. Generally speaking, there is no doubt that humans are not monogamous in the same way that some animals are. First, we must distinguish between sexual monogamy I social monogamy. Sexual monogamy is something strongly determined by genes and consists of the practical impossibility of reproducing with more than one partner. This kind of “fidelity” is something that is far from us, and it is really doubtful that anyone could have much of an interest in living this form of monogamy. For example, some species of flashlight fish: when they reproduce, the male is physically attached to the female, much larger, and he digests his mate until he is completely absorbed.

Infidelity among social monogamists

Sexual monogamy is therefore quite a strange phenomenon in nature, as almost all species that reproduce sexually and take care of reproduction with a specific partner, copulate with others at the slightest change and then continue to engage in family life with the usual partner. . In these cases, we are talking about social monogamy, that is, a pattern of behavior guided by circumstances and not by genetics.

In our case, more or less the same thing happens. The best that can be said is that we are animals that sometimes practice social monogamy, but not sexual monogamy. This is the only type of monogamy we aspire to because we have the opportunity to live loyalty as a pact, Which is reached between two people by own decision, but does not occur spontaneously in members of our species (or at least not in general).

And it is that, although they are frowned upon in some cultures, extramarital affairs are relatively frequent in our species if we compare them to other animals: gibbons, albatrosses, seahorses, etc. Therefore, to regard them as the fruit of the exception would be to deliberately ignore much of reality. In addition, disrespect for genetic monogamy is not the exclusive property of males, as it frequently occurs in both sexes.

If adultery scandalizes us so much, maybe it is because it is a violation of the rules, not because it has no reason to be. It can be argued whether infidelities (understood as severing a relationship with the partner) are somewhat desirable or not, but it is undeniable that they are totally grounded in reality: there are even contact agencies that do infidelity added value in your marketing campaigns.

But then … how and why did the life of a couple originate in our evolutionary history? What does it mean that there is a gap between sexual monogamy and social monogamy? Evolutionary psychology has certain assumptions in this regard.

Evolutionary psychology and its horrible and horrible propositions

In general, when we study human reproductive patterns, we see great variability between cultures, but we do not see a strong genetic predisposition that leads us to have children with one person, as we have seen. However, some evolutionary psychologists believe that in the early stages of our evolution as apes there may have been a propensity for monogamy that natural selection assigned us for its usefulness. What was the main use of having a stable partner, according to them?

The chances of having many sons and daughters survive us. A pretty crude analysis, yes. According to this approach, romantic love, associated with a feeling of obligation towards the couple, is actually born from a kind of selfishness invisible to us. Social monogamy would be, counted and debated, an agreement based on personal interest and in the surrender of a somewhat undeserved trust.

It should be remembered that in itself, adultery should not be a disadvantage from the point of view of natural selection. For example, we have seen that women with children from extramarital affairs may have more reproductive success in certain contexts; that is, they may be more likely to leave their offspring. So it is not even possible for us to say that infidelity is of little use from the point of view of natural selection. But there is another thing to keep in mind if we are to study the covenant of faithfulness: the gender differences.

A mother knows that all the efforts she can make to conceive and raise offspring goes hand in hand with the perpetuation of her genes. Compared to the male, a female is certain that the sacrifices she can make to ensure that her offspring survive will not be in vain. Males do not have this security (there is more reason to doubt whether the semen they are protecting is theirs or not) but, on the other hand, they do not become more vulnerable during the gestation period. Precisely because of this, according to the logic of the natural selection, A male is less valuable than a female as a breeding pair, because the latter in addition to being fertilized takes care of the offspring for a long time. If half the population of a species invest much more time and effort in rearing offspring, evolutionary psychologists will tell us, the individuals that make up that half of the population will become a resource and the other half of the individuals will be in fierce competition. In addition, if the survival of the young is compromised by their fragility, it may be preferable for the male to always be nearby to provide resources and ensure safety. For this reason, an emotional state similar to romantic love, relatively lasting over time and involving the exclusivity of a couple, can be useful.

Monogamy explained by jealousy and the death of children

One of the most scathing conclusions about the origin of social monogamy centers on the important role of something like jealousy. According to a study published in the journal Science, monogamy tends to appear in populations of mammals when the females are very distant from each other and their density in the territory is low, which would make it difficult for males of all monitor them and prevent intruders from impregnating them. So if this is true, the care of the young by the males would be a necessary kind of prejudice.

There is another study, published in PNAS, in which it is suggested that monogamy may have arisen to prevent infanticide in men. This could have been the case because in many polygamous mammals it is common for each dominant male to change the offspring of the previous dominant male this morning so that the females become sexually receptive again. This is all horrible, isn’t it? If you want, you can rethink the monogamous habits of the lanternfish. Let’s see if you recover this way.

You may have noticed that all of the above are painfully reasonable if we think of the human being as a animal guided by certain impulses. In the vast majority of vertebrates, the young already have the ability to move around on their own within hours of birth, and some are completely independent. In comparison, our babies are born nearsighted, unable to coordinate their arms and legs, and even have trouble keeping their heads off the ground. They need all the attention they can get and may not get it enough with the help of one agency.

However, many psychologists and anthropologists believe that it is cultural dynamics, not genetics, that explain the assignment of parenting tasks. This is why we are so unpredictable, according to them. Today there are many people who, despite the experience of romantic love and the need to be attached to a person, do not even consider having babies. Others do not, but they do not believe that this form of affection exists. This may be true because the great brains born of this process of “mating” would have made possible the emergence of a type of thought abstract enough to diversify the forms of love: love of community, love. friends, etc.

All of these bonds are characterized by allowing the creation of close groups of people who can help raise sons and daughters. And the fact is that although the couple formed by the biological parents is not always the one responsible for raising the little ones, there is almost always a protective social circle around the baby, and in certain contexts, this modality may even occur. ‘breeding is more beneficial, as Skinner proposed in his novel Walden Dos. In these situations, love can be seen as the glue that holds together this circle of people engaged in the reproduction and substitution of one another. After all, the roles of “protector figures”, like any other role, are interchangeable.


One of the problems with evolutionary psychology is that it provides explanations for human behavior that most people dislike and which, moreover, are insufficient on their own. By this current of psychology, much of the behavior is explained as being a result adaptation to the environment (In other words, to ensure that our genes are passed on to the next generation). For example, male-female relationships are seen as a game in which one seeks to use the opposite sex to make it more likely that one’s own genes, or genes that most closely resemble our own, are perpetuated. In addition, it should be borne in mind that the object of study of this discipline is something that cannot be experienced: the evolutionary history of species.

In some ways, evolutionary psychology provides possible explanations for certain patterns of behavior, but does not identify or fully explain them. We humans are characterized by our acculturation, and learning explains much of our psychological aspects.

However, if evolution does not determine our behavior, it can explain some very general trends, and it can also help formulate experimental hypotheses about the species to which we currently belong: Homo sapiens.

It is true that the inclination or love we feel for people who are not our children could also be understood as part of a evolutionary strategy to ensure the transmission of our genes. However, he could also understand it as a phenomenon that escapes explanations based on biology. However, if we want to descend from such an idealistic conception of love and plunge ourselves into the swamp of crude scientific explanations, we have to admit that there is nothing in nature or in our genetics that seems to go against occasional infidelities. It is even possible that natural evolution sees these stages with good eyes.

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