The Science Of Jealousy And Betrayal
Take the weight off your shoulders: crises in relationships may be the fault of evolution
Think of the person you love or love. Now, answer which of these two possibilities for betrayal would be the most painful: finding out that your partner had incredible nights of extramarital sex or that you were emotionally involved with another? Men tend to find the first option a knife in the chest. Women often say that the second alternative sounds worse. Although both care about both aspects of infidelity – sexual and emotional – the motivation for jealousy may be different.
For years the evolutionary psychologist David Buss of the University of Texas has found evidence to confirm this difference. In one study, with 234 volunteers, 76% of men and only 32% of women chose the hypothesis of purely sexual involvement as worse than purely emotional. Japanese neuroscientist Hidehiko Takahashi also found evidence in favor of the thesis with 22 people who were in a long relationship (on average, 14.8 months for men and 18.5 months for women).
Monitoring each one with MRI equipment, the researcher asked them to read phrases that suggested situations involving the partner, such as “in a double bed with the ex” and “writing a love letter to another” . The group was then instructed to reread the scenes and assign grades from 0 to 6 according to the degree of jealousy they awakened. Men and women also scored on issues of sexual infidelity, averaging 4.6. For situations that suggested emotional involvement, they scored 4.3 and they scored 4.5 – very close numbers. The surprise came with the result of MRIs.
In them, the amygdala and the hypothalamus, linked to aggression and sexual impulses, had a much greater activity. In them, the loudest structure was the posterior superior temporal groove, which helps in interpreting the intention of others. For scientists, it is as if the feelings of anger, rejection, and fear that accompany betrayal are linked, for men, to the sharing of the partner with another and, for women, the possibility of being left behind. This phenomenon may be the fruit of the evolution of our species.
It is possible that jealousy was born as a strategy of preservation of genetic heritage, probably after two factors completely changed the dynamics of human relations. One of them came when our ancestors started walking on two legs. The mothers began to carry the small children in their arms instead of clinging to their backs, as do the great primates.
With a baby to hold, speed and agility are compromised. Reconciling the search for food with the recent maternity, if it was difficult, was practically impossible. So the men’s responsibility to hunt and keep the danger away to ensure their children’s survival at that stage increased.
The other was the growth of the cranial cavity in hominids. The standard of the australopithecines, our oldest ancestors, was 500 cc. The skull of Homo sapiens is on average 1,300 cm³. Gather a fetus with a larger head and a biped mother with the narrowest pelvis, and you will understand the birth that is the birth of a human. In order not to die all, the wise nature selected the “premature” babies, that is, those that did not develop completely inside the uterus. Us, me and you. The rest of the growth would happen outside.
Therefore, the human brain needs more time to mature: up to seven years. In no other species of primates does the breed take so long to stop demanding permanent care from the parents. Researchers believe that, in the face of so much effort to pass their own genes forward, the man of the past needed to find ways to know that it would not favor the genes of another.
That is, he wanted to be sure of paternity, removing the risk of a rival having sex with his wife. She would not exactly have to make sure the guy did not spread sperm out there, but rather that he did not waste energy and resources on another instead of investing in the survival of the couple’s children. Male emotional involvement with a “competitor” would put the family at risk.
For both of them, at the slightest sign that one of them was finding the neighbor’s grotto more cozy, jealousy would come on the scene and try to motivate “the victim” to take action. Not that all jealous think of children. Much less that husbands say “You can fall in love with another – but not sex,” and women determine that “Sex is released as long as you do not get involved.” This is an instinct. Different challenges of adaptation led to distinct motivations for monopolization of the other.
But why jealousy survives DNA testing to prove paternity and female independence, which has freed women to make their living, decide if and when they want to have children and make choices? Because human emotions are much more complex than a simple cause-and-effect relationship.
Who moved my mozão?
Possessiveness. For your instincts, the other is a conquest of you, not a free soul to wiggle around like you do not own it. Even more so if the free soul in question is based only on the fact that sperm are cheap and ovules are expensive.
Let’s do it by steps. Our species did not spend its life in harems. Nor in eternal bonds of complicity. More likely, we have evolved into a system of serial monogamy, with couples joining together for the time needed to procreate and care for their children until they could walk with their own legs. There are clues to this.
In the primate world, if there is a large difference in size and weight between males and females, it is a sign that a single monkey fecundates the monkeys of the pack and uses truculence to drive competitors away. If the disparity is small or does not exist, the apes tend to mate in pairs.
Male gorillas get twice the height and weight of females. They live like sultans. Small gibbons, similar in body mass, form faithful couples. Men are, on average, only 8% larger and 20% heavier than women, so there is a tendency to join in pairs.
Okay, but monkeys have nothing to do with us … Actually, they have. “Until about 2 million years ago, the difference in size between females and human males was very large, just as with great primates. This suggests a monkey-like social organization in which males had to compete fiercely for access to females, and the sexes did not cooperate with each other either for sustenance or to care for the offspring, “said the American paleoanthropologist Richard Klein of Stanford University.
“About 2 million years ago there was a sharp reduction in the gender difference in size, which is generally interpreted as the beginning of the characteristically human social organization, in which there is a connection between male and female long enough to create a son. They also came to support each other economically. “Klein explains that the most egalitarian proportion of size was mainly because females grew much larger than males. “Perhaps to allow them to expand participation in the search for food with reduced risk.”
This anatomical advance may indicate that when the offspring gains a certain autonomy, females would also be released to seek other partners. A global study by the United Nations has shown that the number of divorces increases after the third year of marriage and peaks in the seventh. Precisely the period necessary to procreate and accompany a child until he gains some autonomy. Female independence has overthrown the figure of the jealous woman staying at home and the traitor husband who works until later. Today, both are subject to jealous attacks and opportunities to find other beds.
The causes of jealousy and betrayal are not just evolutionary. Socio-cultural issues weigh heavily. “There is an overvaluation of beauty and female status. And women began to feel jealous of others who, in their view, have a good appearance or have achieved a better position in the labor market and, therefore, would arouse the desire of the partner, “says psychotherapist Ana Gabriela Andriani. For men, they tend to see as menacing those who seem to be more capable of satisfying women, or who appear more masculine or have power.
“Jealousy is afraid of losing, it is insecurity. Those who are not well resolved can develop feelings of ownership and dependence on each other and want to monitor it, even more with all the technology that facilitates control, “says Ana.
The limit? “At higher levels, the picture becomes pathological. The cause of jealousy ceases to be someone specific and happens to be in anything that arouses the interest of the partner. The recurring thought is ‘He (or she) can not be happy without me.’ “
Whether a couple stays together for weeks, years or forever and whether or not betrays depends on many factors. In the middle enter the feelings, the reason, the beliefs, the values. What is certain is that when a relationship ends, it hurts even in the soul.