Staying Together

Beyond mate acquisition, the task of mate retention becomes crucial. Buss argues that many important benefits arise from maintaining a long-term partner:

“TREMENDOUS BENEFITS FLOW to couples who remain committed. From this unique alliance come efficiencies that include complementary skills, a division of labor, and a sharing of resources, as well as mutual benefits such as a unified front against mutual enemies, a stable home environment for rearing children, and a more extended kin network. To reap these benefits, people must be able to retain the mates they have succeeded in attracting.”

The failure to retain a mate is associated with substantial costs:

“People who fail to stay together incur severe costs. Bonds between extended kin are ripped apart. Essential resources are lost. Children may be exposed to potentially dangerous stepparents. Failure to keep a committed mate can mean wasting all the effort expended in the selection, attraction, courting, and commitment process. Men who fail to prevent the defection of their mate risk losing access to valuable childbearing capabilities and maternal investment. Women who fail to retain their mate risk losing the mate’s resources, protection, and paternal investment. Both sexes incur opportunity costs …”

Relationship dissolution is common:

“Given the high rate of divorce in Western cultures, and the existence of divorce in all cultures, it is obvious that staying together is neither automatic nor inevitable.”

The reasons for relationship dissolution are varied:

“Rivals loom on the periphery, waiting for an opportunity to mate-poach. Existing mates sometimes fail to provide the promised benefits. Some start imposing costs that become too burdensome to bear. Couples are surrounded by people who have agendas at odds with their own and who attempt to loosen or fracture their bond.”

Staying together requires deliberate strategies:

“Staying together can be difficult unless the couple undertakes strategies designed to ensure a successful, committed union.”

Both men and women have a strong interest in maintaining long-term relationships:

“Humans differ from most nonhuman animals in forming long-term and highly committed mateships. Remaining bonded is crucial for women and men alike. Although mate-keeping tactics among insects are performed primarily by males, among humans both men and women use them. Indeed, women are equal to men in the effort they channel toward the adaptive problem of staying together. This equality follows from the evolutionary logic of the value of the reproductive resources that would be lost by a breakup compared with the potential gains an individual could accrue by a breakup. Because men and women who embark on a committed relationship tend to couple with individuals of equivalent desirability, the 8’s with other 8’s and the 6’s with other 6’s, both sexes lose equally, on average, as a result of a breakup.”

The Menace of Mate Poachers

“One reason mate-keeping tactics are crucial is because mate poaching is an ever-present threat. Desirable mates are always in short supply. Glamorous, interesting, attractive, socially skilled people are heavily courted and rapidly removed from the mating pool. Those who succeed in attracting the 9’s and 10’s tend to hold on to them, escalating the effort they allocate to mate guarding.⁷ Transitions between relationships are brief for the beautiful. In modern monogamous societies, for those left on the sidelines of the mating dance, mate shortages get more severe with each passing year.”

When highly attractive individuals are already in long-term relationships, one recurrent solution is mate poaching:

“One unpretty solution to this recurrent quandary is mate poaching. Although many regard efforts to lure someone out of an existing mateship as morally reprehensible, it has a long recorded history.”

Mate poaching is a widespread mating strategy:

“Mate poaching is a common mating strategy. David Schmitt and I discovered that 60 percent of men and 53 percent of women admitted to having attempted to lure someone else’s mate into a committed relationship. Although more than half of these attempts failed, nearly half succeeded. This similarity between the genders in long-term poaching attempts contrasted with poaching efforts targeting brief sexual encounters—60 percent of the men but only 38 percent of the women reported attempting to lure someone else’s mate into a casual sexual encounter. Far higher percentages of both genders said that others had attempted to entice them to leave their own existing relationship—93 percent of the men and 82 percent of the women for long-term love, and 87 percent of the men and 94 percent of the women for a brief sexual encounter.”

Some tactics are specific to mate poaching:

“Schmitt and I found that many of the tactics used to attract mates in other contexts—enhancing appearance, displaying resources, showing kindness, presenting a sense of humor, revealing empathy, and so on—are also effective for the purpose of poaching. Two tactics, however, are specially tailored to enticing mates away from others. The first is temporal invasion, which includes acts such as changing one’s schedule in order to be around the target more often than the target’s current partner, or dropping by when the current partner is off at work or out of town. The second is driving a wedge—infiltrating the existing mateship and actively promoting a breakup. One way to drive a wedge is to boost the target’s self-esteem, conveying messages that enhance their self-perceptions of their own desirability. At the same time, the poacher might communicate that the target is not appreciated by the regular partner: “He doesn’t treat you well,” or “You deserve better,” or “You’re too good for him.” The boost in self-esteem combined with the feeling of being underappreciated is sometimes enough to widen a small crack in a relationship. Through this double-pronged strategy, the mate poacher frees up an already taken mate and sits waiting in the wings when it happens.

Although not terribly admirable, there is good evidence that mate poaching can be an effective mating strategy. Indeed, those who pursue a mate poaching strategy have a larger number of lifetime sex partners and dating partners.”

Counter-tactics against mate poaching have also evolved:

“Humans have evolved their own special strategies for defending against mate poachers and retaining a mate. Women in relationships are especially vigilant about rival women, whereas men tend to be more vigilant about monitoring their own partner. One of the most important mate retention strategies involves continuing to fulfill the desires of one’s mate—the desires that led to the mate selection to begin with. But merely fulfilling these desires may not be enough if rivals are attempting the same thing. Ancestral humans needed a psychological mechanism specifically designed to alert them to potential threats from the outside, an adaptation that would regulate when to deploy mate-guarding strategies. That mechanism was sexual jealousy.”

Women tend to be more concerned with their partner’s emotional involvement with another woman, whereas men tend to be more concerned with sexual involvement with another man:

“Sex differences in the causes of jealousy are not limited to Americans. In one study of jealous men and women in central Europe, 80 percent of the men expressed fears of a sexual nature, such as worrying about their mate’s having intercourse with another man or worrying about their own sexual adequacy. Only 22 percent of the jealous women expressed sexual concerns, the majority focusing instead on the emotional relationship, such as the degree of closeness between their mate and another woman. Men in Hungary, Ireland, Mexico, the Netherlands, the Soviet Union, the United States, and Croatia all showed more intense jealousy than women in response to their partner’s having sexual fantasies about another person. These gender differences in the triggers of jealousy appear to characterize the entire human species.”

Mate Retention Through Fulfilling a Partner’s DesiresMale sexual jealousy can also underlie homicides committed by women:

“Many of the homicides perpetrated by women also appear to have male sexual jealousy at their root. Women who kill men frequently do so to defend themselves against an enraged, threatening, and abusive husband from whom they fear bodily harm.”

Jealousy serves adaptive functions by helping to prevent infidelity and, in men, by increasing confidence in paternity.

Nevertheless, the adaptive functions of jealousy—preventing infidelity and ensuring paternity—are hard to reconcile with the seemingly maladaptive act of killing one’s wife, which undermines reproductive success by destroying a key reproductive resource.

There are also evolutionary explanations for extreme acts of jealousy, including the killing of an unfaithful wife:

“killings that stem from jealousy represent extreme but nonetheless evolved manifestations of the adaptation. Killing one’s wife would not necessarily have been reproductively damaging under all conditions during human evolutionary history. In the first place, if a wife is going to abandon her husband, not only will he lose her reproductive resources anyway, but he also may suffer the additional cost of finding that those resources are channeled to a competitor, which is a double blow to relative reproductive success.

Men who allow themselves to be cuckolded are subject to ridicule and damage to their reputation, especially if they take no retaliatory action.”

The Fragile Union

“It is a remarkable human achievement that a man and a woman who have no genes in common can stay together in a union of solidarity over years, decades, or a lifetime. Because of the many forces that pull couples apart, however, staying together is a fragile proposition that poses a unique set of adaptive problems. Successful solutions typically incorporate several ingredients. First, the mate is supplied with the adaptively relevant resources needed to prevent defection. Second, competitors are kept at bay, for example, by public signals of possession or through concealing the mate from others. Third, mate guarders use emotional manipulation, for example, by provoking jealousy to increase perceptions of desirability, submitting or abasing oneself to the mate, or convincing the mate that alternatives are undesirable. Fourth, cost-inflicting measures come into play, such as punishing a mate for signals of defection or physically assaulting a rival.

These diverse tactics for retaining mates succeed by exploiting the psychological adaptations of mates and rivals. The beneficial tactics, such as giving love and resources, work for a man because they fulfill the psychological desires that led the woman to choose him to begin with. For a woman, enhancing her physical appearance and providing sexual resources succeeds because they match men’s psychology of desire. Indeed, our study of married couples found that men intensify their mate retention efforts when they perceive their partner to be attractive, just as women ramp up their mate retention efforts with partners who are higher in status and income.

Unfortunately, the tactics of threats and violence, which inflict costs on mates and rivals, also work by exploiting the psychological adaptations of others. Just as physical pain leads people to avoid the environmental hazards that can harm them, psychological fear causes people to avoid the wrath of an angry mate. Aggression sometimes pays.”

The next chapter examines the roots and causes of sexual conflict within intimate relationships.

“Once jealousy has become activated by threats to the security of one’s mateship, it can motivate tactics directed at the mate, at the rival, or at oneself. Men and women use an astonishing variety of tactics to keep a mate. A partner’s original mate preferences form the basis for one major strategy: fulfilling the partner’s preferences—that is, providing the sorts of resources he or she initially sought—should be a highly effective method of preserving the relationship.”

Emotional Manipulation

“When tactics such as providing resources, love, and kindness fail, people sometimes resort to desperate emotional tactics to retain their mates, particularly if they are lower in mate value. Examples are crying when the partner indicates interest in others, making the partner feel guilty about such interest, and telling the partner that they are hopelessly dependent on him or her.”

Counterintuitively, submission tactics are used more often by men than by women:

“Submission or self-abasement is another tactic of emotional manipulation. For example, people may go along with everything their mate says, let that person have his or her way, and promise to change—a desperation tactic if there ever was one. In spite of the common stereotype that women are more submissive than men, the mate retention studies show the opposite in mate retention tactics. Men submit to, and abase themselves before, their mates roughly 25 percent more than women do. This gender difference shows up among college dating couples, among newlywed couples, and even among couples after several years of marriage. The gender difference in self-abasement cannot be attributed to a male reporting bias, because their spouses corroborate those reports.”

Provoking sexual jealousy is another mate-retention tactic:

“Another emotional manipulation is intentionally trying to provoke sexual jealousy with the goal of keeping a mate. This tactic includes actions such as dating others to make a mate jealous, talking with people of the opposite sex at parties to incite jealousy, and showing an interest in people of the opposite sex to make a mate angry. People perceive these tactics to be nearly twice as effective for women as for men. A woman who flirts with other men in order to elicit jealousy and thereby hold on to a mate, however, is walking a fine line: eliciting jealousy injudiciously might provoke either violence or abandonment if her mate perceives her as promiscuous.”

Cost-Inflicting Mate Retention Tactics

“Another mate retention tactic is to inflict costs on competitors or on mates through derogation, threats, and violence. These contrast sharply with benefit-conferring tactics such as providing resources or bestowing love and kindness.”

A Dangerous and Deadly Passion

“Men’s sexual jealousy is neither a trivial nor a peripheral emotion in human life. … A wife’s infidelity is sometimes viewed as so extreme a provocation that a “reasonable man” may legally respond with lethal violence. In Texas until 1974, for example, it was legal for a husband to kill his wife and her lover if he did so while the adulterers were engaging in the act of intercourse; their murder was considered a reasonable response to a powerful provocation. Male sexual jealousy is the single most frequent cause of all types of violence directed at wives, including physical abuse and actual murder.”

Male sexual jealousy can also underlie homicides committed by women:

“Many of the homicides perpetrated by women also appear to have male sexual jealousy at their root. Women who kill men frequently do so to defend themselves against an enraged, threatening, and abusive husband from whom they fear bodily harm.”

Jealousy serves adaptive functions by helping to prevent infidelity and, in men, by increasing confidence in paternity.

Nevertheless, the adaptive functions of jealousy—preventing infidelity and ensuring paternity—are hard to reconcile with the seemingly maladaptive act of killing one’s wife, which undermines reproductive success by destroying a key reproductive resource.

There are also evolutionary explanations for extreme acts of jealousy, including the killing of an unfaithful wife:

“killings that stem from jealousy represent extreme but nonetheless evolved manifestations of the adaptation. Killing one’s wife would not necessarily have been reproductively damaging under all conditions during human evolutionary history. In the first place, if a wife is going to abandon her husband, not only will he lose her reproductive resources anyway, but he also may suffer the additional cost of finding that those resources are channeled to a competitor, which is a double blow to relative reproductive success.

Men who allow themselves to be cuckolded are subject to ridicule and damage to their reputation, especially if they take no retaliatory action.”

The Fragile Union

“It is a remarkable human achievement that a man and a woman who have no genes in common can stay together in a union of solidarity over years, decades, or a lifetime. Because of the many forces that pull couples apart, however, staying together is a fragile proposition that poses a unique set of adaptive problems. Successful solutions typically incorporate several ingredients. First, the mate is supplied with the adaptively relevant resources needed to prevent defection. Second, competitors are kept at bay, for example, by public signals of possession or through concealing the mate from others. Third, mate guarders use emotional manipulation, for example, by provoking jealousy to increase perceptions of desirability, submitting or abasing oneself to the mate, or convincing the mate that alternatives are undesirable. Fourth, cost-inflicting measures come into play, such as punishing a mate for signals of defection or physically assaulting a rival.

These diverse tactics for retaining mates succeed by exploiting the psychological adaptations of mates and rivals. The beneficial tactics, such as giving love and resources, work for a man because they fulfill the psychological desires that led the woman to choose him to begin with. For a woman, enhancing her physical appearance and providing sexual resources succeeds because they match men’s psychology of desire. Indeed, our study of married couples found that men intensify their mate retention efforts when they perceive their partner to be attractive, just as women ramp up their mate retention efforts with partners who are higher in status and income.

Unfortunately, the tactics of threats and violence, which inflict costs on mates and rivals, also work by exploiting the psychological adaptations of others. Just as physical pain leads people to avoid the environmental hazards that can harm them, psychological fear causes people to avoid the wrath of an angry mate. Aggression sometimes pays.“

Long-term relationships confer substantial evolutionary benefits for both sexes, including shared resources, coordinated labor, protection against rivals, and stable conditions for childrearing, but they are fragile and costly to lose. Relationship dissolution is common because mates may fail to deliver promised benefits, impose excessive costs, or be targeted by rivals engaging in mate poaching, a widespread and often effective strategy used by both men and women. As a result, humans have evolved a broad repertoire of mate-retention strategies, ranging from benefit-conferring behaviors (love, resources, fulfilling partner preferences) to emotional manipulation, vigilance, jealousy, and, in extreme cases, threats and violence. Sexual jealousy functions as an evolved alarm system designed to prevent infidelity and protect reproductive interests—manifesting differently in men and women—but its activation can sometimes lead to destructive outcomes that appear maladaptive at the individual level, even if they reflect extreme expressions of underlying evolutionary mechanisms. Overall, staying together is not automatic but requires continuous strategic effort in the face of persistent internal and external threats.

The next chapter examines the roots and causes of sexual conflict within intimate relationships.