Beauty fades. Personality remains.
Non-Fiction Notes
Non-Fiction Notes
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When you look at YouTube, you find countless pop-psychology or dating-guru explanations about what men desire and what women desire in a partner. But if you truly want to examine these preferences in depth—if you want solid, evidence-based knowledge about them—you could read The Evolution of Desire by David Buss.
Over countless millennia, humans evolved mating preferences that were adaptive in ancestral environments. These preferences nudged us toward certain behaviors and away from others. For example, women evolved tendencies to avoid mating with men who lacked resources or the ability to acquire and provide them. Men evolved preferences for cues of fertility rather than age or infertility. In ancestral environments, such preferences increased reproductive success.
I still vividly remember the first chapters of the book—there were genuinely ingenious quotes and conceptual gems throughout, and the final (short) chapter was almost philosophical in tone. The book confronts the reader with fundamental questions:
Why do men and women have the mate preferences they do?
What can individuals do to attract a partner?
What can they do to retain a desired partner?
What strategies are used to end relationships?
Why do attraction and attractiveness change over time?
How do people respond to their own changes—and to changes in their partners?
Why does sexual frequency often decline in long-term relationships?
Why do roughly 40% of men report, after four years of marriage, that their wives are withholding sex?
Why are break-ups so common?
Why does sexual conflict appear to be so persistent, rather than inter-sexual harmony?
And how do some couples manage to stay together for decades?These are some of the essential questions one encounters while reading the book. It provided considerable food for thought. It sheds light on one’s past relationships or one’s current relationship and on relationships within one’s social environment. It explains why we have inherited certain adaptive preferences and how these preferences evolved.
But it also raises a deeper question: If these preferences evolved because they were adaptive in ancestral environments, are they still adaptive in modern environments? And what does adaptive behavior look like today? Conversely, what does maladaptive behavior look like in modern contexts?
Once you have read this book, enjoyed it, and acquired a solid understanding of human mating—quite unlike the kind of information one might receive from the average dating guru—the next question naturally arises: Where should the journey continue?
Which books should one read next to deepen knowledge in this area and in related fields?
In my case, Robin Hanson comes to mind—particularly his ideas related to social ally theory, a framework that has been elaborated in considerable depth by Jean-Louis Dessalles. Status, in this perspective, is closely linked to the concept of “your value as an ally.” (Geoffrey Miller might phrase it as “your value as a mate.”) The next step, for me, would be to deepen my understanding of social status as a central organizing principle in human behavior.
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~”You shall know a man by the company he keeps.”
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The central question of the book is:
What constituted adaptive behavior in ancestral environments?A related question follows naturally:
What constitutes adaptive behavior in modern environments?I will shortly provide a comprehensive summary of the entire book. I have already shared summaries of all ten chapters.
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I think the final chapter is a thoughtful and fitting conclusion to the book. It reiterates several essential facts and observations developed earlier and, beyond that, expresses a sense of wonder at the uniquely human capacity to form long-term bonds:
“Men and women have always depended on each other for transporting their genes to future generations. Committed mateships are characterized by a complex web of long-term trust and reciprocity that appears to be unparalleled in other species. In this sense, cooperation between the sexes reaches a pinnacle among humans. Our strategies for cooperation in mating define human nature as much as our evolved capacity for language and culture.”
Beyond this paragraph, I will highlight several other key passages from this short concluding chapter.
—–Some adaptive challenges are not sex-specific. Because women and men alike have faced many similar evolutionary pressures, humans share a broad set of solutions to these challenges:
“Both sexes sweat and shiver to regulate body temperature. Both sexes place a tremendous value on intelligence and dependability in a lifetime mate. Both seek long-term mates who are cooperative, trustworthy, and loyal. And both desire mates who will not inflict crushing costs on them. We are all of one species from the same planet. Recognition of our shared psychology and shared biology is one step toward producing harmony between the sexes.”
But in addition to these shared adaptations, each sex has also faced unique adaptive challenges:
“Against the backdrop of these shared adaptations, gender differences stand out in stark relief and demand explanation. Men and women differ in their psychology of mating solely and specifically in the domains where they have faced recurrently different adaptive problems over the long course of evolutionary history.”
In principle, both sexes can exploit the preferences of the other:
“Some of these gender differences may be unpleasant. Many women dislike being treated as sex objects or valued for qualities largely beyond their control, such as youth and beauty, although some exploit these desires for their own ends. Many men dislike being treated as success objects or valued for the size of their investment portfolio and the importance of their status in a competitive world, although they too sometimes exploit these desires for their own ends.”
It is useful not to ignore the differing preferences of the other sex, but to confront them directly:
“and we squarely confront the differing desires and strategies of each.”
Men and women are not fundamentally united with their own sex:
“we must recognize that no man or woman is fundamentally united with his or her own gender, nor fundamentally at odds with members of the other gender.”
We now arrive at the central theme of the chapter: harmony and cooperation between the sexes.
I will conclude this chapter by presenting its most essential paragraphs:
“Men and women have always depended on each other for transporting their genes to future generations. Committed mateships are characterized by a complex web of long-term trust and reciprocity that appears to be unparalleled in other species. In this sense, cooperation between the sexes reaches a pinnacle among humans. Our strategies for cooperation in mating define human nature as much as our evolved capacity for language and culture.”
“Sexual strategies provide us with some of the conditions that facilitate the achievement of lifelong love. Children, the shared vehicles by which genes survive the journey to future generations, align the interests of a man and a woman and foster enduring mating bonds. Parents share in the delights of producing new life and nurturing their children to maturity. They marvel together as the gift of their union partakes of life’s reproductive cycle. But children also create new sources of conflict, from disputes about dividing the child care to reduced opportunities for nighttime sexual harmony. No blessing is unmixed.”
“Fulfilling each other’s evolved desires is one key to harmony between a man and woman. A woman’s happiness increases when the man brings more economic resources to the union and shows kindness, affection, and commitment. A man’s happiness increases when the woman is more physically attractive than he is, and when she shows kindness, affection, and commitment. Those who fulfill each other’s desires have happier relationships, especially if there are no interested others in the mating pool who could fulfill them more completely. Our evolved desires, in short, provide the essential ingredients for solving the mystery of mating harmony.”
“Knowledge of the multiplicity of our desires may be the most powerful tool for promoting harmony. It is a crowning achievement of humankind that two unrelated individuals can bring all of their individual resources into a lifelong alliance characterized by the remarkable emotion of love. This happens because of the tremendous resources that each person brings to the relationship, the bounty of benefits that flow to those who cooperate, and the sophisticated psychological machinery that we have for forming enduringly valuable mateships. Some of these resources tend to be linked to a person’s gender, such as a woman’s reproductive viability or a man’s physical provisioning capacity. But mating resources typically transcend these reproductive essentials to include such capacities as protection from danger, deterrence of enemies, formation of friendships, tutoring of children, loyalty through thin and thick, and nurturance in times of setback. Each of these resources fulfills one of the many special desires that define our human nature.”
“A profound respect for the other gender should come from the knowledge that we have always depended on each other for the resources required for survival and reproduction. We have always depended on each other for the fulfillment of our desires. These facts may be responsible for the unique feeling of completeness that people experience when they become entwined in the intoxicating grip of love. A lifelong alliance of love is a triumphant achievement of human mating strategies.”
“Our ability to control the consequences of our mating behavior is unprecedented in human evolutionary history and matched by no other species on earth. But we confront these modern novelties with an ancient set of mating strategies that worked in ancestral times and in places that are irretrievably lost. Our mating mechanisms are the living fossils that reveal who we are and where we came from.”
The final six paragraphs were probably the most moving passages in the book, and the ending and conclusion left me deeply thoughtful.
A comprehensive review of the book as a whole, covering all ten chapters, will follow shortly. In this summary, I will highlight the statements and themes that impressed me most.
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Summary of the quotes:
The final chapter of The Evolution of Desire serves as a reflective and unifying conclusion, drawing together the book’s central insights while emphasizing a theme that ultimately transcends conflict: harmony and cooperation between the sexes.The chapter begins by reaffirming that men and women share a large set of adaptations shaped by common evolutionary pressures. Many fundamental desires and solutions—such as the need for trustworthy, cooperative long-term partners—are shared across sexes.
At the same time, the chapter stresses that genuine sex differences exist and demand explanation. These differences arise only in domains where men and women faced recurrently distinct adaptive challenges over evolutionary history, particularly in mating. Such differences can lead to discomfort, especially when individuals feel reduced to narrowly valued traits. Yet both sexes are shown to be capable of exploiting the preferences of the other, underscoring that these dynamics are reciprocal rather than one-sided.
Rather than ignoring or denying these differences, the chapter argues for confronting them directly and honestly. Men and women are not fundamentally allied with their own sex nor inherently opposed to the other; individual interests, strategies, and desires cut across gender lines.
The chapter’s core message is that human mating reaches its highest expression not in competition, but in cooperation. Long-term pair bonds, characterized by trust, reciprocity, and shared investment—especially in children—represent a uniquely human achievement. While children align parental interests and deepen bonds, they also introduce new sources of conflict, reminding us that no evolutionary blessing is without cost.
Harmony in relationships is framed as emerging from the mutual fulfillment of evolved desires. When partners satisfy each other’s needs—economic, emotional, physical, and relational—relationships tend to be happier and more stable.
The chapter closes on a reflective note, emphasizing that love and lifelong partnership are among humanity’s most remarkable achievements. Our ancient mating mechanisms, shaped in ancestral environments, persist even as modern conditions change, revealing both who we are and where we come from.
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This chapter explores sex-specific trajectories in mate value and their behavioral consequences.
Changes over Time
An alpha male can lose dominance over time:
“Although there were four adult males in the troop, Yeroen was responsible for nearly 75 percent of all matings when the females came into estrus.As Yeroen grew older, however, things began to change. A younger male, Luit, experienced a sudden growth spurt and started to challenge Yeroen’s status. Luit gradually stopped displaying the submissive greeting to Yeroen, brazenly showing his fearlessness. Once, Luit approached Yeroen and smacked him hard, and another time Luit used his potentially lethal canines to draw blood. Most of the time, however, the battles were more symbolic, with threats and bluffs in the place of bloodshed. Initially, all the females sided with Yeroen, allowing him to maintain his status. One by one they defected to Luit, however, as the tide turned. After two months, the transition was complete. Yeroen was dethroned and began displaying the submissive greeting to Luit. Mating changes followed. While Luit achieved only 25 percent of the matings during Yeroen’s reign of power, his sexual access doubled to 50 percent when he took over. Yeroen’s sexual access to females dropped to zero.”
As in chimpanzees, human status hierarchies are not static:
“With humans as with chimpanzees, nothing in mating remains static over a lifetime. An individual’s value as a mate changes, depending on gender and circumstances. Because many of the changes individuals experience have occurred repeatedly over human evolutionary history, we have evolved psychological adaptations designed to deal with them. A person who steadily ascends a status hierarchy may suddenly be passed by a more talented newcomer. A hunter’s promise may be cut suddenly short by a debilitating injury. An older woman’s son may become the chief of her tribe. An ignored introvert, long regarded as occupying the bottom rungs of desirability as a mate, may achieve renown through a dazzling invention that is useful to the group. A young married couple bursting with health may tragically discover that one of them is infertile. Ignoring change would have been maladaptive, impeding solutions to critical challenges. We have evolved psychological mechanisms designed to alert us to these changes and motivate us to take problem-solving action.”
Changes in a Woman’s Mate Value
“Because a woman’s desirability as a mate is strongly determined by cues to her reproductivity, that value generally diminishes as she gets older. The woman who attracts a highly desirable husband at age twenty will typically attract a less desirable husband at age forty.”
So a woman’s reproductive value generally diminishes as she ages. Accordingly, perceived female attractiveness declines with age.
“The effect of aging on a woman’s mate value shows up in the changing perceptions of attractiveness through life. In one study in Germany, thirty-two photographs were taken of women ranging in age from eighteen to sixty-four. A group of 252 men and women, from sixteen to sixty years of age, then rated each photograph for its attractiveness on a 9-point scale. The age of the subjects of the photographs strongly determined judgments of female attractiveness, regardless of the age or sex of the rater. Young women drew the highest ratings, old women the lowest. These age effects are even more pronounced when men do the ratings. The change in the perceived attractiveness of women as they move through life is not an arbitrary aspect of a particularly sexist culture. Rather, this change in perceptions reflects the universal psychological adaptations in men that equate cues to a woman’s youth with her value as a mate.”
Some mate preferences depend on individual circumstances:
“Consider the real-life case of a highly successful fifty-year-old business executive who had six children with his wife. She developed a debilitating disease and died young. He subsequently married a woman three years older than himself, and his new wife devoted a major share of her effort to raising his children. To this man, a younger woman who had less experience in child rearing and who wanted children of her own would have been less valuable and might have interfered with his goal of raising his own children. A fifty-three-year-old woman may be especially valuable to a man with children and less valuable to a man with no children who wants to start a family. To the individual selecting a mate, averages are less important than particular circumstances.
The same woman can have a different value to a man when his circumstances change. In the case of the business executive, after his children reached college age, he divorced the woman who had helped raised them, married a twenty-three-year-old Japanese woman, and started a second family. His behavior may have been ruthless and not very admirable, but his circumstances had changed. From his individual perspective, the value of his second wife decreased precipitously when his children were grown, and the attractiveness of the younger woman as his third wife increased to accompany his new circumstances.”
As women age, reproductive success becomes less a matter of producing additional offspring and more a matter of nurturing existing children:
“From the wife’s perspective, as her direct reproductive value declines with age, her reproductive success becomes increasingly linked with nurturing her children, the vehicles that transport her genes into the future. From her husband’s perspective, her parenting skills constitute a valuable and virtually irreplaceable resource. Women often continue to provide economic resources, domestic labor, social status, and other resources, many of which decline less dramatically with age than her reproductive capacity and some of which increase. Among the Tiwi tribe, for example, older women can become powerful political allies of their mates, offering access to an extended network of social alliances and even helping their husbands acquire additional wives. But from the perspective of other men on the mating market, an older woman’s desirability as a prospective mate is generally low, not only because her direct reproductive value has declined but also because her efforts may already be monopolized by the care of her existing children and eventually her grandchildren.”
Changes in Sexual Desire
“One of the most prominent changes within marriage over time occurs in the realm of sex. Among newlywed couples, with each passing year men increasingly complain that their wives withhold sex. Although only 14 percent of men complain that their newlywed brides have refused to have sex during the first year of marriage, 43 percent express this feeling four years later. Women’s complaints that their husbands refuse to have sex with them increase from 4 percent in the first year to 18 percent in the fifth year. Both men and women increasingly charge their partner with refusing sex, although more than twice as many men as women voice this complaint.”
The transition to parenthood alters sexual frequency:
“The arrival of a baby depressed the frequency of sex even more: after the birth, the rate of intercourse averaged about one-third of what it had been during the first month of marriage. Although more extensive studies over longer time periods are needed to confirm this finding, it suggests that the birth of a baby has a long-lasting effect on marital sex, as mating effort shifts to parental effort.”
Changes in Commitment
Marital commitment is often experienced as declining over time, as reflected in reduced affection and attentiveness.:
“Women and men become increasingly distressed by their partner’s failure to show affection and attention, which suggests a lowered commitment to the relationship. Women are more distressed than men by declining affection. Whereas only 8 percent of newlywed women complain about their partner’s failure to express love, 18 percent of women voice this complaint by the time they are four years into the marriage.13 In comparison, only 4 percent of newlywed men are upset about their wives’ failure to express love, which doubles to 8 percent by the fourth year of marriage. Whereas 64 percent of newlywed women complain that their husbands sometimes fail to pay attention when they speak, 80 percent of women are disturbed by this behavior by the fourth and fifth years of marriage. Fewer husbands overall show distress about their partners’ inattentiveness, but the increase in this complaint over time parallels that of their wives, rising from 18 percent to 34 percent during the first four years of marriage.”
In addition, increasing inattention to a partner’s feelings is observed over time:
“Another indication of the withdrawal of commitment over time is one spouse ignoring the other’s feelings. Among newlywed women, 35 percent express distress about having their feelings ignored, whereas four years later this figure has jumped to 57 percent. The comparable figures for complaints by men are 12 percent in the first year and 32 percent in the fourth. These changes signify a gradual diminution of commitment to a spouse over time, which occurs for both sexes but is more upsetting to women than to men.”
Another source of tension over time is the increase in perceived demands for attention and commitment:
“While women are more disturbed about men’s increasing failure to show commitment through affection and attention, men are more distressed by their wives’ growing demands for commitment. Whereas 22 percent of newlywed men complain that their wives demand too much of their time, 36 percent of husbands express upset about this demand by the fourth year of marriage. The comparable figures for women are only 2 percent and 7 percent. Similarly, 16 percent of newlywed men express distress over their wives’ demands for attention, whereas 29 percent voice this complaint in the fourth marital year. The comparable figures for women are only 3 percent and 8 percent. Thus, although both genders show increasing distress about their partners’ demands for commitment, more men than women are troubled by these changes.”
In the context of jealousy, men intensify mate-guarding toward younger wives, whereas women’s mate-guarding is largely unrelated to their partner’s age:
“Husbands of younger women were more likely to glare at other men who paid attention to their wives and sometimes threatened them with bodily harm. In contrast, wives’ efforts to keep older husbands were just as frequent as their efforts devoted to keeping younger husbands. Regardless of the husband’s age, there was no difference in women’s vigilance, monopolization of time, and appearance enhancement tactics. The intensity of women’s efforts to guard their mates is unrelated to the age of the man, showing a marked contrast to men’s reliance on a woman’s age to calibrate the intensity of their guarding.”
Changes in Men’s Mate Value
“While women’s desirability as mates declines predictably with age, the same does not apply to men’s. The reason is that many of the key qualities that contribute to a man’s value are not as closely or as predictably linked with age. These components include a man’s intelligence, cooperativeness, parenting proclivities, political alliances, kin networks, coalitions, and, importantly, ability and willingness to provide resources to a woman and her children.”
Male and female mate value follow markedly different age-related trajectories:
“Men’s value in supplying resources, indicated by cues such as income and social status, shows markedly different changes with age than women’s reproductive value. There are two important differences: men’s resources and social status typically peak much later in life than women’s reproductive value, and men differ more markedly from one another in the resources and social status they accrue. Men’s resources and status sometimes plummet, sometimes remain constant, and sometimes skyrocket with increasing age, whereas women’s reproductive value declines steadily and inexorably with age.”
Male social status is typically acquired later in life rather than in youth:
“In no known culture do teenage boys enjoy the highest status. Among the Tiwi tribe, men are typically at least thirty years old—and often middle-aged—before they are in a position of sufficient status to acquire a wife or two. Young Tiwi men lack the political alliances to garner much status.”
This pattern is also evident in Western societies:
“In the decade between the ages of twenty-five and thirty-four, men’s income attains only two-thirds of its eventual peak. Not until the decades from ages thirty-five to fifty-four does men’s income in the United States achieve its peak. From age fifty-five on, men’s income declines, undoubtedly because some men retire, become incapacitated, or lose the ability to command their previous salaries. These income averages conceal great variability, because some men’s resources continue to increase throughout their old age, whereas other men remain poor throughout their lives.”
Men and women of similar age tend to differ in mate desirability:
“Because older men tend to have more status and resources than younger men, men and women of the same age differ on average in their value as mates. In the same decade between the ages of sixteen and twenty-five when women peak in fertility and reproductive value, men’s income and status are typically the lowest that they will be in their adult lives. When most women between the ages of thirty-five and forty-four are rapidly approaching the end of their reproductive years, most men in the same decade are just approaching the peak of their earning capacity. To the extent that the central ingredients of desirability are a woman’s reproductive value and a man’s resource capacity, men and women of comparable age are not typically comparable in desirability.”
Earlier Death of Men
Low mate desirability in men is associated with increased risk-taking behavior:
“In short, men low in desirability, as indicated by being unemployed, unmarried, and young, seem especially prone to risk taking, which sometimes becomes lethal. The point is not that killing per se is necessarily an adaptation but rather that men’s evolved sexual psychologies are designed to respond to dire mating conditions by increasing the amount of risk they are willing to take.”
A Mating Crisis—Especially for Educated Women
Skewed sex ratios have consequences that extend beyond mate choice. Changes in the balance between men and women across the lifespan alter mating strategies, intensify competition, and can increase the risk of coercive behavior among men with low mate value:
“The existence of large numbers of men who are unable to attract a mate may also increase sexual aggression and rape. Violence often becomes the strategy of people who lack resources that would otherwise elicit voluntary compliance with their wishes. Rape is sometimes perpetrated by marginal men who lack the status and resources that women seek in long-term mates. Furthermore, the likelihood of war is apparently higher in societies with a high ratio of males than in societies with a low ratio of males, supporting the theory that competition among males intensifies at times of a surplus of males.Changes in the ratio of men to women throughout life cause corresponding shifts in mating strategies. Adolescent men often live in a world where available women are in scarce supply, because women prefer mature men with position and affluence. Young men’s strategies reflect these local conditions of female scarcity, because they engage in highly risky competition strategies, committing the vast majority of violent crimes of sexual coercion, robbery, battery, and murder. In one study, for example, 71 percent of the men arrested for rape were between the ages of fifteen and twenty-nine. These are crimes of coercion against women whom men cannot attract or control through positive incentives.
As meAs women get older, men loosen the grip of guarding, and a higher and higher proportion of women pursue extramarital affairs, reaching a maximum as women approach the end of their reproductive years. Whereas for men affairs are often motivated by the desire for sexual variety, for women affairs are motivated more by emotional goals and may represent an effort to switch mates while they are still reproductively vibrant. Women seem to know that their desirability on the mating market will be higher if they leave their husbands sooner rather than later. After menopause, women shift their effort toward parenting and grandparenting, aiding the survival and reproduction of their descendants rather than continuing to reproduce directly. Women pay for their reproductive strategy of early and rapid reproduction in the currency of a shorter period of fertility.”
Late reproductive years are associated with an increased likelihood of mate switching among women.
“Given all the changes that befall men and women over their lifetimes, it is remarkable that in fact 50 percent of them manage to remain together through thick and thin. The lifelong convergence of interests between two genetically unrelated individuals may be the most extraordinary feat in the evolutionary story of human mating. Just as we have evolved mechanisms that draw us into conflict, we have adaptations that enable us to live harmoniously with the other sex. My lab’s massive cross-cultural study, for example, found that as men and women age they place less value on physical appearance in a mate and more value on enduring qualities such as dependability and having a pleasing disposition—qualities important for long-term mating success. The adaptations that promote this strategic harmony between the sexes, just as much as the mechanisms that produce strife, stem from the adaptive logic of human mating.”
That in some cases relative harmony between the sexes is achieved and long-term cooperation is sustained is a remarkable achievement.
This leads directly to the next and final chapter of The Evolution of Human Desire, “Harmony Between the Sexes.”
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Short Summary:
Human mating dynamics are fundamentally dynamic across the lifespan, shaped by changing status, reproductive capacity, resources, and individual circumstances. Neither dominance nor desirability is fixed: as illustrated in chimpanzees and humans alike, shifts in age, health, status, and opportunity can rapidly alter mating success. Evolution has therefore favored psychological mechanisms that monitor such changes and motivate adaptive responses.For women, mate value is closely tied to reproductive capacity, which declines predictably with age. This decline is reflected in consistent cross-cultural patterns of perceived attractiveness, largely driven by evolved male preferences for cues to fertility and youth. As direct reproduction becomes less viable, women’s reproductive success increasingly depends on parental and grandparental investment, as well as social, economic, and political contributions—resources that may retain or even increase their value within an established family but reduce desirability on the broader mating market.
Male mate value follows a very different trajectory. Because it is linked more strongly to status, resources, alliances, and competence—qualities that often peak later in life—men’s desirability varies widely and less predictably with age. Social status is rarely attained in youth and typically accumulates through adulthood, a pattern observed in both small-scale societies and modern Western economies. As a result, men and women of the same age are often not comparable in mate desirability, with women peaking earlier in reproductive value and men later in resource capacity.
These shifting asymmetries influence sexual behavior, commitment, jealousy, and conflict within long-term relationships. Over time, sexual frequency tends to decline, particularly after the transition to parenthood, as mating effort gives way to parental effort. Partners increasingly report reduced affection, attentiveness, and emotional responsiveness, alongside growing tension over perceived demands for commitment. Men tend to be more distressed by increasing demands, whereas women are more distressed by declining affection.
Sex differences also emerge in jealousy and mate guarding. Men calibrate guarding intensity strongly to a woman’s age, intensifying efforts toward younger wives, whereas women’s mate-guarding behavior is largely independent of a man’s age. In contexts of low mate value—especially among young, unemployed, unmarried men—risk-taking increases, sometimes lethally, reflecting evolved responses to poor mating prospects rather than violence as an adaptation per se.
At the population level, skewed sex ratios and mating inequalities can intensify competition, coercion, and social instability. At the individual level, changing circumstances can radically alter mate preferences, leading to mate switching, particularly among women approaching the end of their reproductive years. After menopause, women typically redirect effort toward kin investment rather than further reproduction.
Despite these pervasive sources of conflict, divergence, and instability, a striking fact remains: a substantial proportion of men and women sustain long-term pair bonds. With age, both sexes increasingly prioritize traits such as dependability, emotional stability, and cooperativeness—qualities that support enduring partnerships. The ability of two genetically unrelated individuals to achieve relative harmony and long-term cooperation stands as one of the most remarkable outcomes of human mating psychology.
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After reviewing the final chapter, I will turn to an overall review of the book, highlighting what caught my attention most. -
Breaking Up
“Divorce and remarriage are so common in the United States that nearly 50 percent of all children do not live with both of their genetic parents. Stepfamilies are rapidly becoming the norm, not the exception.”
Why do individuals choose to leave long-term committed relationships?
“People end committed relationships for many reasons. A spouse may start imposing new or larger costs, for example, or a better opportunity for a mate may come along. Staying in a bad relationship can be costly—lost resources, missed mating opportunities, physical abuse, inadequate care for children, and emotional abuse. These costs all interfere with successful solutions to the critical adaptive problems of survival and reproduction. New mating opportunities, superior resources, better child care, and better allies are some of the benefits that may flow to people who leave bad relationships.”
Adaptive Problems Leading to Breakups
“Many mates in ancestral times became injured and died before old age. Men, for example, sustained wounds or were killed in combat between warring tribes. The paleontological record reveals fascinating evidence of aggression between men. Pieces of spears and knives have been found lodged in the remains of human rib cages. Injuries to skulls and ribs are found more frequently on male than on female skeletons, revealing that physical combat was primarily a male activity. Intriguingly, more injuries are located on the left sides of skulls and rib cages, suggesting a greater prevalence of right-handed attackers. The earliest known homicide victim in the paleontological record is a Neanderthal man who was stabbed in the chest by a right-hander roughly 50,000 years ago. These highly patterned injuries cannot be explained as accidents. They demonstrate that injury and death at the hands of other people have been recurrent hazards in human evolutionary history.”
In ancestral times, besides disease, homicide was a major cause of death.
“Injury, disease, or the death of a mate were not the only hazards to force ancestral mates to look elsewhere. A woman’s husband could lose status within the group, be ostracized, become dominated by a rival male, prove to be a bad father, prove to be infertile, fail as a hunter, start abusing her, initiate affairs, direct resources to other women, or turn out to be sexually impotent. A man’s wife could fail at gathering food, mishandle family resources, prove to be a bad mother, prove to be infertile, decline his sexual advances, cheat on him, or get pregnant by another man. Either sex could contract debilitating diseases or become riddled with parasites. Life events sometimes take a terrible toll on a mate full of vitality when initially chosen. Once a selected spouse decreases in value, alternatives become attractive.”
Beyond mortality and mate-value decline, additional forces favored the dissolution of long-term pair bonds:
“A mate’s decline in value and potential death represented only two of the conditions that might have diverted a person’s attention to alternatives. Another critical condition is an increase in one’s own desirability, which opens up an array of alternatives that were previously unobtainable. A man, for example, could sometimes dramatically elevate his status by performing an unusually brave deed, such as killing a large animal, defeating another man in combat, or saving someone’s child from harm. Sudden increases in a man’s status opened up new mating possibilities with younger, more attractive mates or multiple mates, who could make a current mate pale by comparison. Mating options mushroomed for men who managed to boost their status. Because a woman’s value as a mate was closely tied with her reproductive value, she usually could not elevate her desirability to the same extent that men could. Nevertheless, women could improve their mate value by acquiring status or power, showing unusual adeptness at dealing with crises, displaying exceptional wisdom, or having sons, daughters, or other kin who achieved elevated positions within the group. These possibilities for changes in mating value are still with us today.”
Thus, in ancestral environments, three primary reasons could lead to the voluntary disruption of a pair bond.
“In sum, three major general circumstances could have led an ancestral person to leave a long-term mate: when a current mate became less desirable because of a decrease in abilities or resources or a failure to provide the reproductively relevant resources expected in the initial selection; when the person experienced an increase in his or her own resources or reputation that opened up previously unobtainable mating possibilities; and when compelling alternatives became available. Because these three conditions are likely to have regularly recurred among our ancestors, it is reasonable to expect that humans evolved psychological mechanisms to evaluate the costs and benefits of existing relationships in comparison with the perceived alternatives. These adaptations would have been attuned to changes in the value of a mate, continued to identify and gauge mating alternatives, and led to the pursuit of backup mates or potential replacement mates.”
Adaptations for Breaking Up
“Ancestral conditions that favored breakups posed recurrent adaptive challenges over human evolutionary history. People who were oblivious to a decrease in their mate’s value, who were totally unprepared to find a new mate in the event of their mate’s death, or who failed to trade up to a higher-quality mate when offered the opportunity would have been at a tremendous reproductive disadvantage compared with those who perceived and acted on these conditions.”
To elaborate further,
“It may be disconcerting to acknowledge it, but most people continue to assess outside options while in a committed relationship. Men’s banter, when it does not center on sports or work, often revolves around the appearance and sexual availability of women in their social circles. Married women talk as well about which men are attractive, available, and high in status. These discussions accomplish the critical goals of exchanging information and assessing the mating terrain. It pays to monitor alternatives with an eye toward mating opportunities. Those who stick it out with an undesirable mate through thick and thin may receive our admiration, but their kind would not have reproduced as successfully in ancestral times and are not well represented among us today. Men and women evaluate alternative mating possibilities even if they have no immediate intention to act on them. It pays to plan ahead.”
Mate preferences persist within marriage:
“Mate preferences continue to operate during marriage, being directed not just at comparing the array of potential mates but at comparing those alternatives with the current mate. Men’s preference for young, attractive women does not disappear once they make a long-term commitment to a mate; nor does women’s attention to the status and prestige of other men. Indeed, one’s mate provides a handy standard for repeated comparisons. Research from my lab, spearheaded by Dan Conroy-Beam, discovered that happiness in a mateship is partly determined by the discrepancies between one’s partner’s mate value and the value of alternative mates in the local environment. People assess how well their mates stack up to the competition and become unhappy if their mates suffer by these comparisons. A decision to keep or get rid of one’s mate depends on the outcome of these calculations, which may not be made consciously.”
Mate evaluation processes operate without conscious awareness:
“A man whose increased status opens up better mating alternatives does not think to himself, Well, if I leave my current wife, I can increase my reproductive success by mating with younger, more reproductively valuable women. He simply finds other women increasingly attractive and his current relationship less satisfactory. A woman whose mate abuses her does not think to herself, My reproductive success and that of my children will increase if I leave this cost-inflicting mate. She thinks instead that she had better get herself and her children to safety. Our mateship dissolution adaptations operate without our awareness of the adaptive problems they solve.”
How are mates effectively rejected?
“One effective tactic for expelling a mate, in evolutionary psychological terms, would be to violate the mate’s expectations, so that the mate no longer desired to maintain the relationship. That is, rather than leaving themselves, some people try to drive their partner to take that step. Ancestral men could withhold resources or give signals that investments were being channeled to other women. Women could decrease a man’s certainty of paternity by engaging in infidelities or simply withholding sex from him. Cruel, unkind, inconsiderate, malevolent, harmful, or caustic acts would be effective tactics for expelling a mate for both women and men because such acts violate the universal preferences held by both of them for mates who are kind and empathic. These tactics have in common the exploitation of existing psychological mechanisms in the other sex—adaptations that alert people to the possibility that they have chosen a mate unwisely, or that their mate has changed in unwanted ways, and that perhaps they should cut their losses.”
Infidelity
“The most powerful indicator of a man’s failure to retain access to a woman’s reproductive capacity is her infidelity. The most powerful cue to a woman’s failure to retain access to a man’s resources is his infidelity. Among the forty-three causes of conjugal dissolution, ranging from the absence of male children to sexual neglect, adultery is the single most pervasive cause, being cited in eighty-eight societies.”
Infidelity as a tactic for mate dissolution:
“Knowing that infidelity causes conjugal dissolution, some people may use it intentionally to get out of a bad marriage. In a study of the breakup of mates, we asked one hundred men and women which tactics they would use to get out of a bad relationship. Subsequently, a different group of fifty-four individuals evaluated each tactic for its effectiveness in accomplishing the goal. One common method for getting rid of an unwanted mate was to start an affair, perhaps by sleeping around in an obvious manner or arranging to be seen with a member of the other gender in some other questionable situation.
Sometimes an actual affair is not carried out but is merely alluded to or implied. People use the tactics of flirting with others or telling a partner that they are in love with someone else so that the mate will end the relationship. A related tactic is to express a wish to date other people in order to be sure that the two of them are truly right for each other, a means of gracefully exiting from the relationship through a gradual transition out of commitment.”
Infertility
“Infertility is exceeded only by infidelity as the most frequently cited cause of divorce across societies.”
Infertility and infidelity are the leading causes of divorce worldwide:
“In evolutionary terms, it makes perfect sense that infertility and infidelity are the most prevalent causes of divorce worldwide. Both represent the strongest and most direct failures to deliver the reproductive resources that provide the evolutionary raison d’être for long-term mating. People do not consciously calculate that their fitness suffers from these events. Rather, infidelity and infertility are adaptive problems that exerted selection pressure on human ancestors for a psychology attuned to reproductive failures. Just as having sex tends to lead to the production of babies even though the people involved may have no awareness of the reproductive logic involved, so anger leads a person to leave an unfaithful or infertile mate, with no conscious articulation of the underlying adaptive logic being required. The fact that couples who are childless by choice are nonetheless devastated by infidelity shows that our psychological mechanisms continue to operate in modern contexts, even those far removed from the selection pressures that gave rise to them.”
Sexual Withdrawal
“A wife who refuses to have sex with her husband is effectively depriving him of access to her reproductive value, although neither mate necessarily thinks about it in these terms. Since sex throughout human evolutionary history has been necessary for reproduction, depriving a man of sex may eliminate the reproductive dividends on the investment that he has expended in obtaining his wife. It may also signal that she is allocating her sexuality to another man. Men have evolved psychological adaptations that alert them to this form of interference with their sexual strategies.”
Women have been found to employ the following breakup tactics:
“Women described their tactics for breaking up variously as refusing to have physical contact with their mate, becoming cold and distant sexually, refusing to let her mate touch her body, and declining sexual requests. These tactics were employed almost exclusively by women.”
This tactic appears to be effective, as illustrated by the following case:
“The success of this tactic is illustrated by one woman’s account in the study on the breakup of mates. She complained to a friend that her repeated attempts to break off with her husband had failed. She wanted advice. Further discussion revealed that, although she seriously wanted to get rid of her husband, she never had refused his sexual advances. Her friend suggested that she try it. A week later she reported that her husband had become enraged at her sexual refusal and, after two days, had packed his bags and left. They were divorced shortly thereafter. If women give sex to get love and men give love to get sex, then depriving a man of sex may be a reliable way to stop his love and hasten his departure.”
Lack of Economic Support
“A man’s ability and willingness to provide a woman with resources are central to his mate value, central to her selection of him as a partner, central to the tactics that men use to attract mates, and central to the tactics that men use to retain mates. In evolutionary terms, a man’s failure to provide resources to his wife and her children should therefore have been a major gender-linked cause of breakups. Men who are unable or unwilling to supply these resources fail to fulfill a key criterion on which women initially select them.”
Cruelty and Unkindness
“Worldwide, one of the most highly valued characteristics in a committed mate is kindness. It signals a willingness to engage in a cooperative alliance, an essential ingredient for success in long-term mating. Disagreeable people make poor mates. Mates who are irritable, violent, abusive, derogatory, beat children, destroy possessions, neglect chores, and alienate friends impose severe costs psychologically, socially, and physically.Given these costs, cruelty, maltreatment, and ruthlessness rank among the most frequent causes of marital breakup in the cross-cultural study on conjugal dissolution, cited in fifty-four societies. In all cultures these traits are exceeded only by adultery and infertility as causes for splitting up. According to one study of marital dissolution, 63 percent of divorced women reported that their husbands abused them emotionally, and 29 percent reported that their husbands abused them physically.
Unkindness and psychological cruelty may in some cases be related to events that occur during the course of a marriage, particularly adultery and infertility. Infertility, for example, often sparks harsh words between mates in tribal India. One Indian husband said: “We went to each other for seven years till we were weary, and still there was no child; every time my wife’s period began she abused me saying, ‘Are you a man? Haven’t you any strength?’ And I used to feel miserable and ashamed.” Eventually, the couple divorced.
Adultery also provokes cruelty and unkindness. When a Quiche woman commits adultery, her husband is likely to nag, insult, scold, abuse, and even starve her. Worldwide, adulterous wives are beaten, raped, scorned, verbally abused, and injured by enraged husbands. Thus, some forms of unkindness are evoked by reproductively damaging events that occur within the marriage. Cruelty and unkindness, in other words, may in part be symptoms of other underlying causes of divorce. Psychological adaptations and behavioral strategies become activated to solve these costly problems.In other cases, unkindness is a personality characteristic of one spouse that is stable over time. In my lab’s study of newlywed couples, we examined the links between the personality characteristics of one spouse and the problems they caused their mates. The wives of disagreeable husbands expressed distress because their husbands were condescending, physically abusive, verbally abusive, unfaithful, inconsiderate, moody, insulting, and self-centered. The wives of disagreeable men complain that their husbands treat them as inferiors, demand too much time and attention, and ignore their wives’ feelings. They slap their wives, hit them, and call them nasty names. They have sex with other women. They fail to help with the household chores. They abuse alcohol and insult their wives’ appearance. Not surprisingly, spouses of disagreeable people tend to be miserable with the marriage, and by the fourth year of marriage many seek separation and divorce.“
Role of unkind behavior in inducing relationship dissolution:
“Given the premium that people place on kindness in a mate, it is not surprising that one of the most effective tactics for getting rid of a bad mate is to act mean, cruel, caustic, and quarrelsome. Men and women say that effective tactics for getting mates to leave include treating them badly, insulting them to others publicly, intentionally hurting their feelings, creating a fight, yelling without explanation, and escalating a trivial disagreement into a fight.
Cruelty and unkindness are used worldwide as a tactic for expelling a mate.”
Tactics for Coping with Breakups
“Breaking up a romantic relationship is among the most traumatic life events people experience. In studies of stressful life events, it always ranks in the top five. Only experiences such as the death of a child or the death of a spouse are seen as more stressful. Friendship networks can become strained, and plunging into the mating market anew can be frightening. Breakups can threaten one’s social status since our mates are often seen by others as key contributors to the esteem in which we are held. Moreover, breakups often end the flow of benefits to which we have become accustomed, be they economic, sexual, or social.”Implications for a Lasting Relationship
“To maximize the chances of preserving a long-term bond, couples would do well to remain faithful; produce children together; secure ample economic resources; act kind, generous, and understanding; and attend to their mate’s sexual and emotional desires. These actions do not guarantee a successful relationship, but they increase the odds substantially.”
The next chapter is titled “Changes Over Time.” -
Sexual Conflict
“NOVELS, SONGS, SOAP operas, and tabloids tell us about battles between men and women and the pain they inflict on each other. Wives bemoan their husbands’ neglect; husbands are bewildered by their wives’ moodiness. “Men are emotionally constricted,” say women. “Women are emotional powder kegs,” say men. Men want sex too soon, too fast; women impose frustrating delays. Are these just stereotypes?”
Drama is commonly perceived as an essential element of life and of relationships between the sexes.
“Conflict between the sexes is best understood in the broader context of social conflict. Social conflict occurs whenever one person interferes with the achievement of the goal of another person. Interference can take various forms. Among men, for example, conflict occurs when they compete for precisely the same resources, such as position in a status hierarchy or access to a desirable sex partner. Because young, attractive women are in scarcer supply than men who seek them, some men get shut out. One man’s gain becomes other men’s loss. Similarly, two women who desire the same responsible, kind, or high-achieving man come into conflict; if one woman gets what she wants, the other woman does without.”
Having outlined conflict within the sexes, the analysis now turns to conflict between the sexes:
“Conflict also erupts between men and women whenever one sex interferes with the goals and desires of the other sex. In the sexual arena, for example, a man who seeks sex without investing in his partner short-circuits a mating goal of many women, who want greater emotional commitment and higher investment. The interference runs both ways. A woman who requires a long courtship and heavy investment interferes with a man’s short-term sexual strategy.Conflict per se serves no evolutionary purpose, and it is generally not adaptive at all for individuals to get into struggles with the other sex. On the contrary, conflict is typically costly. Sexual conflict is an undesirable outcome of the fact that people’s sexual strategies interfere with each other. We have inherited from our ancestors, however, psychological solutions to problems of conflict management.”
How do people respond when another party interferes with their mating goals?
“The emotions of anger, distress, and upset are key psychological solutions that have evolved in part to alert people to interference with their mating goals. These emotions serve several related functions. They draw our attention to the problematic events, focusing attention on them and momentarily screening out less relevant events. They mark those events for storage in memory and easy retrieval from memory. Emotions also lead to action, causing people to strive to eliminate the source of the problem or to head off future battles.
Because men and women have different sexual strategies, they differ in which events activate negative emotions. Men who seek casual sex without commitment or involvement, for example, often upset women, whereas women who lead men to invest for a period of time and then withhold sex that was enticingly implied will cause men to get angry.”
Sexual Accessibility and Conflict over Perceived Mate Value
“Disagreements about sexual access or availability may be the most common sources of conflict between men and women. When 121 college students kept daily diaries of their dating activities for four weeks, 47 percent reported having one or more disagreements about the desired level of sexual intimacy.2 Men sometimes seek sex with a minimum of investment. Men guard their resources and are extraordinarily choosy about whom they invest in. They are “resource coy” in order to preserve their investments for a long-term mate or for multiple casual sex partners, sometimes serially and sometimes in rotation. Because women’s long-term sexual strategies loom large in their repertoire, they often seek signals of investment before agreeing to sex. The investment that women covet is precisely the investment that men most selectively allocate. The sexual access that men seek is precisely the resource that women are so selective about apportioning.”
In addition, conflict can arise from disagreements over perceived desirability:
“Conflict over perceived desirability, where one person feels resentment because the other ignores him or her as a potential mate, is often where the first battle line is drawn in the mating market. People with higher desirability have more resources to offer and so can attract a mate with a higher value. Those with a low value must settle for less. Sometimes, however, a person may feel worthy of consideration and yet the other person disagrees.”
Some women do not welcome romantic attention from men they perceive as having lower mate value.
“This point is illustrated by a female colleague who frequents country-and-western bars. She reports that she is sometimes approached by a beer-drinking, T-shirted, baseball-capped, stubble-faced blue-collar worker who asks her to dance. When she declines, men like this sometimes get verbally abusive, saying, for example, “What’s the matter, bitch, I’m not good enough for you?” Although she simply turns her back, that is precisely what she thinks: they are not good enough for her. Her unspoken message is that she can obtain someone better, and this message angers rebuffed men. The rock star Jim Morrison of The Doors once noted that women seem wicked when one is unwanted. Differences between people’s perceptions of mate value cause conflict.”
Cognitive Biases in Sexual Mind Reading
“Humans live in an uncertain mating world. We must make inferences about others’ intentions and emotional states. How attracted is he to her? How committed is she to him? Does that smile signal sexual interest or mere friendliness? Some psychological states, such as smoldering passion for another person, are intentionally concealed, rendering uncertainty greater and speculation more tortuous. We are forced to make inferences about hidden intentions and concealed deeds using a collage of cues that are only probabilistically related to their actual existence. An unexplained scent on one’s romantic partner, for example, could signal sexual betrayal, or it could be an innocuous aroma acquired during a casual conversation or a walk through a shopping mall.”
Why might women employ sexual withholding as a mating strategy?
“For women, sexual withholding fulfills several possible functions. One is to preserve their ability to choose men of high mate value—those who are willing to commit emotionally, to invest materially, or to contribute high-quality genes, or ideally all three. Women withhold sex from certain men and selectively allocate it to others of their own choosing. Moreover, by withholding sex, women increase its value and render it a scarce resource. Scarcity ratchets up the price that men are willing to pay for it. If the only way men can gain sexual access is by heavy investment, then they will make that investment. Under conditions of sexual scarcity, men who fail to invest fail to mate. This creates another conflict between a man and a woman, since her withholding interferes with his strategy of gaining sex sooner and with fewer emotional strings attached.Another function of sexual withholding is to manipulate a man’s perception of a woman’s value as a mate. Because highly desirable women are less sexually accessible to the average man by definition, a woman may influence a man’s perception of her desirability by withholding sexual access. Highly desirable women are, in fact, hard to get, so men interpret the difficulty of gaining sexual access to a woman as a cue to her mate value. Finally, sexual withholding, at least initially, may encourage a man to evaluate a woman as a long-term mate rather than a sexual fling. Granting sexual access early often causes a man to see a woman as a casual mate.
By withholding sex, women create challenges for men. They circumvent the component of men’s mating strategy that involves seeking low-cost sex. Certainly, women have a right to choose when, where, and with whom they want to have sex. But the exercise of that choice interferes with one of men’s deep-seated sexual strategies and is therefore experienced by men as bothersome or upsetting; hence, it is one of the key sources of conflict between the sexes.”
Emotional Commitment
“In the most abstract sense, people solve adaptive problems by one of two means—by their own labor or by securing the labor of others. In principle, people who can successfully obtain the effort of others with a minimal investment can be more successful in solving life’s adaptive problems. It is often in a woman’s best interest, for example, to have a man so devoted to her that all of his energies are channeled to her and her children. It is often in a man’s best interest, however, to allocate only a portion of his resources to one woman, reserving the rest for additional adaptive problems, such as seeking additional mating opportunities or achieving higher social status. Hence, individual women and men are often at odds over each other’s commitments.”
Is men’s emotional restraint a source of conflict in long-term relationships?
“A key sign of conflict over commitment centers on the irritation women express about men’s tendency not to express their feelings openly. One of the most frequent complaints women have about men is that they are emotionally constricted. Among newlyweds, for example, 45 percent of women, in contrast to only 24 percent of men, complain that their mates fail to express their true feelings. During the dating phase, roughly 25 percent of women complain that their partners ignore their feelings; this increases to 30 percent in the first year of marriage. By the fourth year of marriage, 59 percent of women complain that their husbands ignore their feelings. In contrast, only 12 percent of newlywed men and 32 percent of men in their fourth year of marriage make this complaint.”
Why is emotional expressiveness in a mate particularly important from a woman’s perspective?
“From a woman’s vantage point, what are the benefits she gains by getting a man to express his emotions, and what are the costs she incurs if he fails to express them? From a man’s vantage point, are there benefits to withholding the expression of emotions and costs to expressing them? One source of this gender difference stems from the fact that men’s reproductive resources are more easily divided than women’s. Within any one-year period, for example, a woman can only get pregnant by one man, and so the bulk of her reproductive resources cannot be easily partitioned. Within that same year, a man can divide his resources by investing in two or more women.”
In addition, men’s emotional restraint can be understood as a strategic form of information concealment.
“One reason men fail to express their emotions is that investing less emotionally in a relationship frees up resources that can be channeled toward other women or other goals. As in many negotiable exchanges, it is often in a man’s best interest not to reveal how strong his desires are or how intensely he is willing to commit. Turkish rug dealers wear dark glasses to conceal their interest. Gamblers strive for a poker face to disguise telltale emotions that give away their hands. Emotions often betray the degree of investment. If emotions are concealed, one’s sexual strategies remain concealed as well. The lack of information causes women to agonize, to sift through the available signs trying to discern where men really stand. College women, far more than college men, report spending time recalling and dissecting with friends conversations and activities they experienced with the people they are dating. They try to analyze their partner’s “real” inner states, intentions, emotions, and motivations. Conflict over commitment resides at the core of complaints about men’s emotional constrictedness.“
If women criticize men for emotional constriction, men often voice the opposite complaint—excessive emotionality:
“While women complain that men are emotionally constricted, men commonly complain that women are too moody and emotional. Roughly 30 percent of dating men, in contrast to 19 percent of dating women, complain about their partner’s moodiness. These figures increase to 34 percent of men during the first year of marriage and jump to 49 percent of men by the fourth year of marriage, in contrast with married women, of whom only 25 percent make these complaints.”
Why do men tend to dislike moodiness in their partners?
“Moody partners absorb time and psychological energy. Appeasing responses, such as efforts to get the partner out of the bad mood and putting one’s own plans aside temporarily, take up energy at the expense of other goals. Women impose these costs on men as a tactic for eliciting commitment. A moody woman may be saying: “You had better increase your commitment to me, or else I will burdon you with my emotional volatility.” It is one tactic in women’s repertoire for eliciting male commitment. Men dislike it because it requires that they expend effort that could be allocated to solving other adaptive challenges.“
Moodiness can also function as a test of relationship strength:
“Moodiness also functions as an assessment device to test the strength of the bond. Women use moodiness to impose small costs on their mates and then use men’s reactions to the costs as a gauge of their degree of commitment. If a man is unwilling to tolerate these costs, it is a cue that his commitment is low. Men’s willingness to tolerate the costs and to be responsive to the increasing demands for investment signals a greater level of commitment. Either way, the woman gains valuable information about the strength of the bond.“
Resource Investment
“In addition to emotional commitment, couples also skirmish over the investment of time, energy, and resources. Neglect and unreliability are manifestations of commitment conflicts. More than one-third of all dating and married women complain that their partners neglect them, reject them, and subject them to unreliable treatment. Among their common complaints are that men do not spend enough time with them, fail to call when they say they will, show up late, and cancel arrangements at the last minute. Roughly twice as many women as men complain about these events. Approximately 38 percent of dating women, for example—but only 12 percent of dating men—complain that their partners sometimes fail to call them when they say they will.”Why are neglect and unreliability interpreted as serious relational threats by women?
“Upset over neglect and unreliability reflects a conflict over investment of time and effort. It takes effort to be on time. Reliability requires relinquishing time and resources that could be channeled toward other goals. Neglect signals a low investment, indicating that the man lacks the depth of commitment necessary to perform acts that require even minimal cost for the woman’s benefit.”
Marriage does not resolve conflicts over investment.
“Marriage does not extinguish conflict over investments. Indeed, as the marriage progresses from the newlywed year to the fourth year, women’s complaints about neglect and unreliability increase. Roughly 41 percent of newlywed women and 45 percent of women married for four years express irritation that their partners do not spend enough time with them. The analogous figures for men are only 4 percent during the newlywed year and 12 percent during the fourth year of marriage.”
Conflicts over investment frequently center on financial resources:
“Conflicts over investment often center on money. A study of American couples found that money is one of the most frequent sources of conflict. Seventy-two percent of married couples fight about money at least once a year, with 15 percent fighting more than once a month. Interestingly, couples fight more about how the money they have is to be allocated than about how much money they have in their joint pool of resources.American men, far more often than women, complain that their spouse spends too much money on clothes. The percentage of men who express this grievance starts at 12 percent during the newlywed year and increases to 26 percent by the fourth year of marriage. In contrast, among women, only 5 percent during the newlywed year and 7 percent during the fifth year of marriage are bothered by their husband’s spending on clothes. Both, however, complain equally that their spouse spends too much money in general. Nearly one-third of men and women by the fourth year of marriage complain about their spouse’s overexpenditure of mutual resources.“
Women are particularly likely to complain about insufficient financial investment or resource acquisition:
“More women than men complain that their spouse fails to channel the money they do earn to them, especially noting their failure to buy them gifts. By the fifth year of marriage, roughly one-third of married women voice this complaint; in contrast, only 10 percent of husbands express similar complaints. Conflict between the sexes corresponds remarkably well with the initial gender-linked preferences in a mate. Women select mates in part for their economic resources and, once married, complain more than men that those resources are not forthcoming or abundant enough.”
Concluding Remarks
“Conflicts between men and women pervade their interactions on the mating market, in the workplace, and within relationships. These range from conflicts over sexual access in dating couples to fights over commitment and investment among married couples … most sexual conflicts have their origins in men’s and women’s evolved mating strategies. The strategies pursued by members of one sex often interfere with those of the other sex as each tries to influence the other toward gender-linked mating goals.”
Under what conditions do men and women experience anger?
“Both genders have psychological adaptations, such as anger, sadness, and jealousy, that alert them to interference with their mating strategies. A woman’s anger is evoked most intensely in the specific contexts in which a man interferes with her mating strategies—for example, if he acts in condescending, abusive, controlling, or sexually coercive ways toward her, constricting her personal power or freedom of choice. A man’s anger is most intensely evoked when a woman interferes with his mating strategies, for example, by spurning his advances, refusing to have sex with him, or hooking up with another man.”
This dynamic gives rise to an evolutionary arms race between the sexes:
“For each escalating test that women impose on men to gauge the depth of their commitment, men develop increasingly more elaborate strategies to mimic or minimize commitment. This development in turn favors more refined and subtle tests by women to weed out the pretenders. And for every form of abuse inflicted by one sex on the other, the other evolves methods for circumventing the manipulations. As women evolve better and more sophisticated strategies to achieve their mating goals, men evolve increasingly sophisticated strategies to achieve theirs. Because the mating goals of the sexes interfere with each other within evolutionarily delimited domains, there is no evolutionary end to the spiral.”
When the costs imposed by a partner become too high, adaptive emotions can lead to relationship dissolution:
“Adaptive emotions such as anger and psychological pain, however, help women and men reduce the costs they incur when someone attempts to interfere with their mating strategies. In the context of dating or marriage, these emotions sometimes lead to the end of the relationship.”
Some extended sections of this chapter—specifically those addressing deception, sexual assault, and rape—were not reviewed here. Consistent with the concluding argument of the previous section, the following chapter turns to relationship dissolution and examines when leaving a relationship becomes adaptive. -
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. -
I have read the first five chapters of The Evolution of Desire, which roughly cover the first half of the book. What is in it for the reader? Human mating is a realm filled with clichés, and the world is saturated with loud and often false information on this topic. For that reason, it is essential to gain a realistic understanding of the true character of human mating.
Probably the first five chapters contain the most essential information in the book. They provide honest descriptions of what traits women desire in a mate and how these desires emerged in ancestral environments. Likewise, they explain what traits men desire in women and how these preferences also developed under ancestral conditions. The reader learns that the other sex is shaped in its mate-choice mechanisms and inner experience to desire certain types of partners and particular experiences with them.
In addition, the book shows that both sexes are designed to engage in affairs under certain circumstances. It explains why short-term mating strategies exist at all and shows that men and women approach these strategies differently and seek different outcomes when applying them.
Finally, Chapter 5 takes a deeper look at how men and women compete for desirable mates of the opposite sex. This competition occurs through signaling the possession of desired traits and through the denigration of rivals. Here again, different traits are signaled and different traits are targeted for effective derogation.
Cutting through the noise and going straight to the reality of human mating, this book can be very helpful for anyone who wants to take a serious look at the science of human mating. The remaining chapters will be reviewed in a second review, followed by a final review on this blog.
Non-Fiction Notes 