As we learn more about the patterns and structures that have shaped us today, it sometimes seems men are the enemy, the oppressors, or at the very least an alien and incomprehensible species.
—CAROL CASSELL, Swept Away
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?
When I first started exploring the topic of conflict between the sexes, I wanted to survey this potentially expansive terrain. Toward this end, I asked several hundred women and men simply to list all the things that members of the opposite sex did that upset, angered, annoyed, or irritated them.1 People were talkative on the topic. They listed 147 distinct things that someone could do to upset or anger someone of the opposite sex, ranging from condescension, insults, and physical abuse to sexual aggression, sexual withholding, sexism, and sexual infidelity. With this basic list of conflicts in hand, my colleagues and I conducted studies of singles, dating couples, and married couples to identify which sources of conflict occur most often and which produce the greatest distress.
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.
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.
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.
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.
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.
In reading the minds of others, there are two ways to go wrong. You can infer a psychological state that is not there, as when one assumes sexual interest when it is absent. Or you can fail to infer a psychological state that is there, as when one remains oblivious to another’s burning yearnings, sexual or romantic. According to error management theory (EMT), it would be exceedingly unlikely that the cost-benefit consequences of the two types of errors would be identical across their many occurrences.3 We intuitively understand this in the context of smoke alarms, which are typically set to be hypersensitive to any hint of smoke. The costs of occasional false alarms are minor compared to the catastrophic costs of failing to detect a real house fire. EMT extends this logic to cost-benefit consequences in the metric of evolutionary fitness.
According to EMT, asymmetries in the cost-benefit consequences of mind-reading inferences, if they recur over evolutionary time, create selection pressures that produce predictable cognitive biases. Just as smoke alarms are biased to produce more false positives than false negatives, EMT predicts that evolved mind-reading mechanisms will be biased to produce more of one type of inferential error than another. The sexual overperception bias, whereby men possess mind-reading biases designed to minimize the costs of missed sexual opportunities, is a perfect example. EMT provides a cogent explanation for the finding that men appear to falsely infer that women are sexually interested in them when they merely smile, incidentally touch their arm, or are simply friendly.
In one study, 98 men and 102 women watched a ten-minute videotape of a conversation between a male professor and a female student.4 The student visits the professor’s office to ask for a deadline extension for a term paper. The actors in the film are a female drama student and a male drama professor. Neither actor acts flirtatious or provocative, although both have been instructed to behave in a friendly manner. Participants witnessed the tape and then rated the likely intentions of the woman using 7-point scales. Women watching the interaction were more likely to say that the student was trying to be friendly (6.45), not sexy (2.00) or seductive (1.89). Men, while also perceiving friendliness (6.09), were more likely than women to infer seductive (3.38) and sexual (3.84) intentions. Similar results were obtained from a study using photos of a man and women studying together.5 Men rated the photographed women as showing moderate intent to be sexy (4.87) and seductive (4.08), whereas women rating the identical photographs saw considerably less sexual intent (3.11) and less seductive intent (2.61).
Interestingly, men who view themselves as especially high in mate value are especially prone to experience the sexual overperception bias.6 Men who are dispositionally inclined to pursue a short-term mating strategy also exhibit a more pronounced sexual overperception bias—a bias that would facilitate the success of a short-term mating strategy by minimizing lost opportunities.7 A speed-dating study conducted in my lab, led by Carin Perilloux, found that men were especially susceptible to the sexual overperception bias when interacting with physically attractive women—an ironic finding since attractive women are generally very choosy.8 The men were inferring interest in the minds of the women least likely to actually be interested. Nevertheless, as men act on their inferences they do occasionally open up sexual opportunities. If over evolutionary history even a tiny fraction of these sexual misperceptions led to sex, then men would have evolved lower thresholds for inferring women’s sexual or romantic interest. Men’s sexual overperception bias evolved to motivate approach.
Once this male mechanism was in place, it became susceptible to manipulation. Women sometimes use their sexuality as a tactic in such manipulation. In one study of 200 university students, women significantly more than men reported smiling and flirting as a means of eliciting special treatment from members of the opposite sex, even though they had no interest in having sex with those men.9 Women, in short, sometimes exploit men’s sexual overperception bias for their own ends.10 Men’s perception of sexual interest in women combines with women’s intentional exploitation of this psychological adaptation to create a potentially volatile mix. These sexual strategies lead to conflict over the desired level of sexual intimacy, over men’s feeling that women lead them on, and over women’s feeling that men are too pushy in the sexual sphere.
Sexual pushiness sometimes slips over the line into sexual aggressiveness—the vigorous pursuit of sexual access despite a woman’s reluctance or resistance. Sexual aggressiveness is one strategy men use to minimize the costs they incur for sexual access, although this strategy carries its own costs in the possibility of retaliation and damage to their reputation. Acts of sexual aggression include demanding or forcing sexual intimacy, failing to get mutual agreement for sex, and touching a woman’s body without her permission. In one study, my lab asked women to evaluate 147 potentially upsetting actions that a man could perform. Women rated sexual aggression on average to be 6.50, or close to the 7.00 maximum of distress. No other kinds of acts that men could perform, including verbal abuse and nonsexual physical abuse, were judged by women to be as upsetting as sexual aggression. Contrary to a view held by some men, women do not want forced sex. Women sometimes have fantasies that involve forced sex with a man who turns out to be rich and handsome, and sometimes the theme of forced sex occurs in romance novels, but neither of these circumstances means that women actually desire forced or nonconsensual sex.11
Men, in sharp contrast, seem considerably less bothered if a woman is sexually aggressive; they see it as relatively innocuous compared with other sources of discomfort. On the same 7-point scale, for example, men judged the group of sexually aggressive acts to be only 3.02, or only lightly upsetting, when performed by a woman. A few men spontaneously commented that they would find such acts sexually arousing if a woman performed them. Other sources of distress, such as a mate’s infidelity and verbal or physical abuse, were seen by men as far more upsetting—6.04 and 5.55, respectively—than sexual aggression by a woman.
A disturbing difference between the genders is that men consistently underestimate how unacceptable sexual aggression is to women. When asked to judge its negative impact on women, men rated it only 5.80 on the 7-point scale, which is significantly lower than women’s own rating of 6.50. The implication of this alarming source of conflict between the sexes is that some men may be inclined to use aggressive sexual acts because they fail to comprehend how distressing these acts really are to women. In addition to creating conflict, men’s failure to correctly understand the psychological pain that women experience from sexual aggression may be one cause of men’s lack of empathy for rape victims.12 The callous remark by a Texas politician that if a woman cannot escape a rape, she should just lie back and enjoy it, could only have been uttered by someone who fails to understand the magnitude of the trauma experienced by women who are victims of sexual aggression.
Women, in contrast, overestimated how upsetting sexual aggression by a woman is to a man, judging it to be 5.13, or moderately upsetting, in contrast to men’s rating of only 3.02.13 Men and women both err in cross-sex mind-reading. These cognitive biases may result from false beliefs about the other gender, mistakenly extrapolating from their own projected reactions. Men seem to think that women are more like them than they really are, and women seem to think that men are more like them than they really are. Acquiring knowledge about gender differences in perceptions of sexual aggression might be one step toward reducing sexual conflict.
The flip side of the coin of sexual aggression is sexual withholding. Men consistently complain about women’s sexual withholding, defined by such acts as sexual teasing, saying no to having sex, and leading a man on and then turning him away. On the same 7-point scale of magnitude of upset, men judged sexual withholding to be 5.03, whereas women judged it to be 4.29. Both genders are bothered by sexual withholding, but men significantly more so than women.
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.
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.14
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.
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.15 Conflict over commitment resides at the core of complaints about men’s emotional constrictedness.
Concealment of sexual strategies is not the only force driving men to remain stoic, nor are men necessarily inept at expressing emotions under different circumstances. Similarly, women sometimes conceal their emotions for strategic reasons. In the mating arena, however, discerning the long-term intentions of a potential partner is less critical for men than for women. Women in ancestral times who erred in their assessment suffered severe costs by granting sexual access to men who failed to commit to them. Getting a man to express himself emotionally represents one tactic that women use to gain access to the important information they need to discern a man’s degree of commitment. Perhaps that’s why singer Madonna exhorts women to put love to the test by getting men to express themselves; only then will they know if his love is real.
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.16
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 also functions as an assessment device to test the strength of the bond.17 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.
Neither the functions of moodiness nor the functions of emotional reserve require conscious thought to be strategically enacted. Women need not be aware that they are attempting to test the strength of the man’s commitment. Men need not be aware that they are trying to minimize their commitment to preserve some for efforts outside the couple. The functions of adaptations for dealing with sexual conflict over emotional expression remain largely hidden from view.
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.18
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 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.19
The flip side of the coin of neglect is dependency and possessiveness. Conflict develops when one mate absorbs so much energy that the partner’s freedom is restricted. A common grievance of married men, far more than of married women, is that their spouse takes up too much of their time and energy. Thirty-six percent of married men, in contrast with only 7 percent of married women, express irritation that their spouse demands too much of their time. Twenty-nine percent of married men, but only 8 percent of married women, complain that their mates demand too much attention.20
These gender differences in demands on time and attention reflect a continuing conflict about investment. Women try to sequester their mate’s investment. Some men resist monopolization, striving to channel a portion of their effort toward other adaptive problems such as raising their status or acquiring additional mates. More than three times as many men as women voice possessiveness complaints. For men, historically, there was a large and direct reproductive payoff to preserving some investment for acquiring status and additional mates. For women, the benefits were smaller, less direct, and often more costly because they risked the loss of the existing mate’s investment of time and resources. Wives may be possessive and demanding because they do not want their husband’s limited investment to be diverted away from them.
Another manifestation of investment conflict centers on grievances about a partner’s selfishness. Among married couples, 38 percent of men and 39 percent of women complain that their partner acts selfishly. Similarly, 37 percent of married women and 31 percent of married men lament their partner’s self-centeredness. The core of selfishness centers on allocating resources to oneself at the expense of others, such as a spouse or children. Complaints about self-centeredness rise dramatically during the course of marriage. During the first year of marriage, only 13 percent of women and 15 percent of men complain that their partner is self-centered. By the fourth year of marriage, the numbers more than double.21
To understand these dramatic changes, consider the critical signals of investment during the courting stage. Effective courting communicates a willingness to put a mate’s interests before your own, or at least on par with your own. These cues are powerful tactics for attracting a mate and are displayed most floridly while courting. After the mateship is reasonably secure, the tactics signaling selflessness subside because their initial function of attracting a mate recedes. Each gender becomes freer to indulge the self and to channel less effort toward the partner. This is what long-term couples mean when they grumble that their partner takes them for granted.
The picture is not a very pretty one, but humans were not designed by natural selection to coexist in mating bliss. They were designed for individual survival and genetic reproduction. The psychological mechanisms fashioned by these ruthless evolutionary criteria are sometimes selfish.
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.22 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.23
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.
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.24 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.
Deception
Conflicts between the sexes over sexual access, emotional commitment, and investment of resources reach more dramatic proportions when we add deception to the mix. Deception flourishes in the plant and animal world. Some orchids, for example, have brilliantly colored petals and centers that mimic the colors, shapes, and scents of female wasps of the species Scolia ciliata.25 Male wasps, powerfully attracted by these scents and colors, land on the orchids the way they would land on a female’s back. This event is followed by a pseudo-copulation, in which the male moves rapidly over the rigid hairs of the upper surface of the flower, which mimic the hairs on a female wasp’s abdomen. He probes the orchid in an apparent search for complementary female genital structures, incidentally picking up the plant’s pollen. Failing to find the exact structures needed for ejaculation, however, the male moves on to another pseudo-female. Orchids deceive the male wasp for the function of cross-pollination.
Humans also engage in sexual deception. A colleague used to go to upscale hotel bars and pick up men who would take her out to dinner. During dinner, she was friendly, flirtatious, sexy, and engaging. Toward the end of dinner, she would excuse herself to go to the women’s room, then slip out the back door and disappear into the night. Sometimes she did this alone, sometimes with a girlfriend. Her targets were often businessmen from out of town, whom she would be unlikely to encounter again. Although she spoke no lies, she was a sexual deceiver. She used sexual cues to elicit resources and then left sneakily without following through with sex. One can’t feel too sorry for the guys, though, since many were married and pursuing their own forms of deception.
Although this tactic may be unusual, its underlying theme occurs repeatedly in ordinary behavior in various guises. Women are apparently aware of the sexual effects they have on men. When 104 college women were asked how often they flirted with a man to get something they wanted, such as a favor or special treatment, knowing that they did not want to have sex with him, they gave this action on average a frequency of 3 on a 4-point scale, where 3 signified “sometimes” and 4 signified “often.” The comparable figure for men was 2. Women gave similar responses to questions about using sexual hints to gain favors and attention, yet admitted that they had no intention of having sex with the targets of these hints.26 Some women acknowledge being sexual deceivers as one tactic in their strategic arsenal.
Although women are more likely to be sexual deceivers, men are more likely to be commitment deceivers. Consider what a thirty-three-year-old man had to say about the commitment implied by declarations of love:
You would think saying “I love you” to a woman to thrill and entice her isn’t necessary anymore. But that’s not so. These three words have a toniclike effect. I blurt out a declaration of love whenever I’m in the heat of passion. I’m not always believed, but it adds to the occasion for both of us. It’s not exactly a deception on my part, I have to feel something for her. And, what the hell, it usually seems like the right thing to say at the time.27
When my lab asked 112 college men whether they had ever exaggerated the depth of their feelings for a woman in order to have sex with her, 71 percent admitted to having done so, compared with only 39 percent of the women who were asked a parallel question. When the women were asked whether a man had ever deceived them by his exaggeration of the depth of his feelings in order to have sex with her, 97 percent admitted that they had experienced this tactic at the hands of men; in contrast, only 59 percent of the men had experienced this tactic at the hands of women.28
Among married couples, deception continues in the form of sexual infidelity. The motivations for male infidelity are clear, since ancestral men who had extramarital affairs might sire additional children and thereby gain a reproductive advantage over their more loyal rivals. Women get extremely upset by male infidelity because it signals that the man is diverting resources to other women and might even defect from their relationship. Women stand to lose the entire investment secured through the marriage, and replacing a husband is not always easy, especially if a woman has children. Consequently, evolutionists have predicted that women will be far more upset by an affair that contains emotional involvement than about one that does not, because emotional involvement typically signals outright defection rather than the less costly siphoning off of a fraction of resources. Women turn out to be more forgiving and less upset if no emotional involvement accompanies their husband’s fling.29 Men seem to know this. When caught having an affair, men often plead that the other woman “means nothing.”
In the human mating dance, the costs of being deceived about a potential mate’s resources and commitment are carried more heavily by women. An ancestral man who made a poor choice in sex partners risked losing only a small portion of time, energy, and resources, although he may also have evoked the rage of a jealous boyfriend or protective father. An ancestral woman who made a poor choice of a casual mate, allowing herself to be deceived about the man’s long-term intentions, risked enduring pregnancy, childbirth, and child care unaided and being less able to attract an alternative mate, since existing children are seen as costs by potential mates on the mating market.
Because the deceived can suffer large losses, selection favored the evolution of psychological vigilance to detect cues to deception and to prevent its occurrence. Humans today are experiencing one more cycle in the endless spiral of an evolutionary arms race between deception by one gender and detection by the other. As the deceptive tactics get more subtle, the ability to detect deception becomes more sensitive.
Women guard against deception. When they are seeking a committed relationship, an important first-line defense is imposing courtship costs by requiring extended time, energy, and costly signals before consenting to sex. More time buys more assessment. It allows a woman greater opportunity to evaluate a man, to assess how committed he is to her, and to detect whether he is burdened by prior commitments to other women and children. Men who seek to deceive women about their ultimate intentions typically tire of extended courtship. They go elsewhere for sex partners who are more readily available.
Although women have developed strategies for penetrating men’s deception, men clearly cannot ignore deception at the hands of women. This is especially true when men seek spouses. Accurate assessments of women’s reproductive value, resources, alliances, and fidelity become paramount. This is vividly illustrated in a scene from Tennessee Williams’s play A Streetcar Named Desire. Mitch is on a date with Blanche DuBois, a former high school teacher to whom he is engaged to be married but who has deceived him about her sexual past with other men, including a sexual relationship with a student that caused her expulsion from the school. A friend has just alerted Mitch to Blanche’s past, so he aggressively tells her that he has always seen her only at night under a dim light, never in a well-lit room. He turns on a bright light, from which Blanche recoils, but he sees that she is older than she had led him to believe. He confronts her with what he has heard about her flamboyant sexual past. She plaintively asks Mitch whether he will still marry her. He says, “No, I don’t think I’ll marry you now,” as he nevertheless approaches her menacingly for sex.30
Given the importance that men attach to looks and sexual exclusivity in a potential mate, they are especially sensitive to deception about a woman’s age and sexual history. Men are keenly attuned to information about women’s sexual reputations. Vigilance guards them against deception about two of the most reproductively important considerations for a man seeking a long-term mate—her reproductive value and the likelihood that her value will be channeled exclusively to him.
Unfortunately, conflict between the sexes does not end with battles about sexual access, commitment, or deception. Sometimes it takes more violent forms.
Intimate Partner Violence
Violence takes several forms. One is psychological abuse, which causes a wife to feel less valuable in the relationship, to lower her sense of desirability and make her feel lucky to have secured the husband, and to diminish her perceived prospects on the mating market if she is contemplating abandoning the mateship.31
Two functional tactics of psychological abuse are condescension and contempt. Condescension manifests through two methods. In one, a man places more value on his opinions simply because he is a man. In another, a man treats his mate as if she were stupid or inferior. Newlywed men condescend roughly twice as often as their wives do. These acts have the effect of lowering the wife’s sense of her own desirability.32 Condescension, one form of which is “mansplaining,” may function to increase the victim’s investment and commitment to the relationship and to bend the victim’s energies toward the goals of the abuser.33 Victims often feel that, because their mating alternatives are not rosy, they must strive valiantly to placate the current mate. They also appease the partner to avoid incurring his further wrath.
Psychological abuse sometimes escalates from verbal abuse to physical violence. Men’s motives for battering women center heavily on coercive control. One researcher attended the trials of 100 Canadian couples engaged in litigation over the husband’s violence toward the wife. The researcher concluded that at the core of nearly all the cases was the husband’s frustration about his inability to control his wife, whom he frequently accused of being a whore or of having sex with other men.34 A study of thirty-one battered American women found that jealousy was the main topic of spousal arguments. Jealousy led to physical abuse in 52 percent of the cases, with 94 percent listing jealousy as a frequent cause of the history of battering in the relationship.35 In yet another study, for 95 percent of sixty battered wives who had sought the assistance of a clinic in North Carolina, “morbid jealousy,” such as jealousy if the wife left the house for any reason or if she maintained friendships with other men or women, had evoked violent reactions from their husbands.36 The coercive constraint of women, particularly in sexual matters, underlies most cases of physical abuse.
Spouse abuse is obviously a dangerous game to play. The abuser may be seeking increased commitment and investment, but the tactic may backfire and produce a desire to leave instead. Alternatively, this form of abuse may represent a last-ditch attempt to hold on to a mate who is on the brink of leaving. In this sense, the abuser treads on thin ice. He risks triggering the decision that the relationship is too costly to endure. Perhaps this is why abusers are often profusely apologetic after the abuse, crying, pleading, and promising that they will never do it again.37
Partner abuse is not a Western invention; it occurs cross-culturally. Among the Yanomamö, for example, husbands regularly strike their wives with sticks for offenses as slight as serving tea too slowly.38 Interestingly, Yanomamö wives often regard physical abuse as a sign of the depth of their husband’s love for them—an interpretation probably not shared by their modern American counterparts. Whatever the interpretation, these beatings have the effect of subordinating Yanomamö women to their husbands.
Men sometimes abuse their partner by insulting her physical appearance. Although only 5 percent of newlywed men do so, the percentage triples by the fourth year of marriage. In marked contrast, only 1 percent of newlywed women insult their husband’s appearance, and only 5 percent of longer-married women do so. Given that a woman’s physical appearance is typically a key component of her mate value, women find these derogations especially distressing. Men may insult their appearance to lower women’s perception of their own desirability, thereby securing a more favorable power balance within the relationship.
As with other destructive tendencies, the fact that abuse has an adaptive logic behind it does not mean that people should accept it, desire it, or be lax about curtailing it. On the contrary, greater understanding of the logic behind abusive tactics and the contexts in which they occur should lead to more effective means of curtailing them. Men who have certain personality dispositions, such as being emotionally unstable, are four times as likely to abuse their wives as emotionally stable men.39 Discrepancies in the desirability of the two partners, a long distance between the couple’s residence and that of the woman’s kin, and the absence of legal penalties for abuse are contexts that put women at increased risk.
Sexual Harassment
Although abuse and other forms of conflict are common within couples, sexual conflict is also common outside of mating relationships. For instance, disagreements over sexual access sometimes occur in the workplace, where people often seek casual and romantic mates. The search may cross a line and become sexual harassment, which can be defined as “unwanted and unsolicited sexual attention from other individuals in the workplace.”40 It includes mild forms such as unwanted staring at a woman’s breasts and body, what one woman described as the “up-down” as a man scans her physique from head to toe. It includes sexual comments, such as “nice ass” or “beautiful body.” And it includes physical violations, such as the touching of breasts, buttocks, or thighs. Sexual harassment clearly produces conflict between the sexes.
Evolutionary psychology offers insight into the psychology that motivates sexual harassment and the circumstances that trigger it. Sexual harassment is typically motivated by the desire for short-term sexual access, although it is sometimes motivated by power or by a search for a lasting romantic relationship. Evolved sexual strategies shed light on sexual harassment through the profiles of typical victims, including such features as their age, marital status, and physical attractiveness; their reactions to unwanted sexual advances; and the conditions under which they were harassed.
Victims of sexual harassment are not random. In one study of complaints filed with the Illinois Department of Human Rights over a two-year period, seventy-six complaints were filed by women and only five by men.41 Another study of 10,644 federal government employees found that 42 percent of the women, but only 15 percent of the men, had experienced sexual harassment at some point in their career.42 Among complaints filed in Canada under human rights legislation, ninety-three cases were filed by women and only two by men. In both cases filed by men, the harassers were men rather than women.43 Women are generally the victims and men the perpetrators. Nonetheless, because women experience greater distress than do men in response to acts of sexual aggressiveness, women might be more likely to file official complaints than men when harassed.
The victims of sexual harassment are disproportionately young, physically attractive, single women. Women over forty-five are less likely to be victims.44 One study found that women between the ages of twenty and thirty-five filed 72 percent of the complaints of harassment, whereas they represented only 43 percent of the workforce at the time. Women over forty-five, who represented 28 percent of the workforce, filed only 5 percent of the complaints.45 The victims of sexual harassment are women whose relative youth evokes male sexual interest in general.
Single and divorced women are subjected to more sexual harassment than married women. In one study, single women represented only 25 percent of the workforce but filed 43 percent of complaints; married women, comprising 55 percent of the workforce, filed only 31 percent of the complaints.46 There may be several reasons for these differences. Husbands sometimes function as “bodyguards,” deterring would-be harassers. Moreover, men perceive single women to be more receptive to sexual advances or more easily sexually exploitable.
Reactions to sexual harassment also follow evolutionary psychological logic. When men and women were asked how they would feel if a coworker of the opposite sex asked them to have sex, 63 percent of the women said that they would be insulted, while only 17 percent said that they would feel flattered.47 Men’s reactions were just the opposite—only 15 percent would be insulted, and 67 percent would feel flattered. These reactions fit with the evolutionary psychology of human mating—men generally have more positive emotional reactions to the prospect of casual sex. Women react more negatively to being treated as mere sex objects.
The degree of anguish women experience from unwanted sexual advances, however, depends in part on the status of the harasser. My lab asked 109 college women how upset they would feel if a man they did not know, whose occupational status varied from low to high, persisted in asking them out on a date despite repeated refusals, a relatively modest form of harassment. On a 7-point scale, women said that they would be most upset by advances from construction workers (4.04), garbage collectors (4.32), cleaning men (4.19), and gas station attendants (4.13), and least upset by persistent advances from premedical students (2.65), graduate students (2.80), and successful rock stars (2.71).48 Women’s distress in response to the same acts of harassment varies depending on men’s status.
Women’s reactions to sexual harassment also depend heavily on whether the motivation of the harasser is perceived to be sexual or romantic. Sexual bribery, attaching job promotions to sex, and other cues that the person is interested only in casual sex are more likely to be labeled as harassment than are signals of potential interest that may transcend the purely sexual, such as nonsexual touching, complimentary looks, or flirting.49 When 110 college women used a 7-point scale to rate how sexually harassing a series of acts by their coworkers would be, acts such as putting his hand on a woman’s genital area (6.81) or trying to corner a woman when no one else was around (6.03) were seen as extremely harassing. In contrast, acts such as telling a woman that he sincerely liked her and would like to have coffee with her after work was judged to be only 1.50 (1.00 signifying no harassment at all).50 Clearly, short-term sexual and coercive intentions are more harassing than sincere romantic intentions.
These findings about the profiles of sexual harassment victims, the sex differences in emotional reactions, and the importance of the status of the harasser all follow from the evolutionary psychology of human mating strategies. Men have evolved lower thresholds for seeking casual sex, and their sexual overperception bias leads them to infer sexual interest where none exists. These sexual adaptations become activated in the workplace perhaps no less than in any other social context.
Sexual Assault
Rape may be defined as the use of force, or the threat to use force, to obtain sex. Estimates of the number of women who have been raped vary, depending on how inclusive a definition the researcher uses. Some researchers use broad definitions that include instances in which a woman did not perceive that she was raped at the time but admitted later that she did not really want to have intercourse or regretted doing so. Other researchers use stricter definitions that delimit rape to clear cases of forced intercourse against the woman’s will. One large-scale study of 2,016 university women, for example, found that 6 percent had been raped.51 Another study found, however, that almost 15 percent of 380 college women had been involved in sexual intercourse against their will.52 Given the large social stigma attached to victims and the well-known underreporting of rape, these figures probably underestimate the actual numbers of women who have been raped.
The issue of rape has a bearing on human mating strategies, in part because many rapes occur within the context of mating relationships. Dating is a common context for rape. One study found that almost 15 percent of college women had experienced unwanted sexual intercourse in a dating encounter.53 Another study found that, for 63 percent of 347 women, all instances of sexual victimization were perpetrated by dates, lovers, husbands, or de facto partners.54 The most extensive study of rape in marriage found that of nearly 1,000 married women, 14 percent had been raped by their husband.55 Rape in the modern world often does not fit the stereotype of a menacing stranger jumping out of a dark alley.
Men are almost invariably the perpetrators of rape, and most victims are women, although victims also include children and men. It is a matter of controversy within the scientific community whether rape represents an evolved sexual strategy of men or is better understood as a horrifying side effect of men’s general sexual strategy of seeking low-cost casual sex.56 Among scorpionflies, however, the evidence for rape as an evolved strategy is strong. The males have a special anatomical clamp that functions solely in the context of raping a female and not in consensual mating, for which a male offers a nuptial gift.57 Experiments that seal the clamp with wax prevent the male from achieving a forced copulation. Scorpionflies have rape adaptations, but what about humans?
Have Men Evolved Adaptations to Rape?
Controversy about the possibility that men have evolved adaptations to rape erupted in the year 2000 when the biologist Randy Thornhill and the anthropologist Craig Palmer published a book called A Natural History of Rape: Biological Bases of Sexual Coercion.58 Although evolutionary theories of human rape had been published for two decades preceding its publication, their book proved to be a flash point. The authors outline two competing theories of rape, one endorsed by each author. Thornhill proposes the theory that men have evolved rape adaptations—specialized psychological mechanisms for forcing sex on unwilling women as a reproductive strategy. Palmer proposes instead that rape is a by-product of other evolved mechanisms, such as the male desire for sexual variety, a desire for low-cost consensual sex, a psychological sensitivity to sexual opportunities, and the general capacity of men to use physical aggression to achieve a wide variety of goals.
The rape-as-adaptation theory proposes six specialized adaptations that may have evolved in the male mind:
• Assessment of the vulnerability of potential rape victims (for example, in the context of warfare or a non-warfare situation in which a woman lacks the protection of a husband or kin)
• A context-sensitive switch that motivates rape by men who lack sexual access to consenting partners (such as low-status males who cannot obtain mates through regular channels of courtship)
• A preference for maximally fertile rape victims
• An increase in sperm counts of rape ejaculates compared with those occurring in consensual sex
• Male sexual arousal specifically to the use of force or to signs of female resistance to consensual sex
• Context-specific marital rape when sperm competition might exist, such as when there is evidence or suspicion of female infidelity
Evidence supporting these hypothesized adaptations is either absent or ambiguous. Rape is common in war, clearly a context where women are often vulnerable, but so is theft, looting, and property damage. Are there specialized adaptations for all these behaviors, or are they instead either by-products of other psychological mechanisms or merely the output of more general cost-benefit evaluation mechanisms? Decisive studies have not yet been conducted.
Although there is no conclusive evidence supporting the rape-as-adaptation theory, psychological and physiological experiments have revealed some disturbing findings. Laboratory studies that expose men to audio and visual depictions of rape versus mutually consenting sexual encounters find that men display sexual arousal, assessed both by self-report and by penile tumescence, to both consenting and nonconsenting situations. Men apparently are sexually aroused when exposed to sexual scenes, whether or not consent is involved. Nonetheless, other conditions, such as the presence of violence, evidence that the victim experiences pain, and a disgust reaction from the victim, inhibit the sexual arousal of most men.59
These findings cannot differentiate between the two explanatory alternatives: that men have only a general tendency to be sexually aroused in response to witnessing sexual encounters and hence have no distinct adaptations to forced sex, or that men have evolved a distinct rape psychology. Consider a food analogy. Humans, like dogs, salivate when they smell appetizing food, especially if they have not eaten for a while. Suppose that a scientist hypothesizes that humans have a specific adaptation to take food forcibly from others. The scientist then conducts studies in which people are deprived of food for twenty-four hours and thereafter exposed visually to one of two scenes: appetizing food that is given willingly by one person to another person, or equally appetizing food that is forcibly taken from one person by another.60 If this hypothetical experiment finds that people salivate an equal volume to both food scenes, we cannot conclude that people have a distinct food adaptation to “take food forcibly.” All we can conclude is that, when hungry, people seem to salivate when exposed to scenes of food, regardless of the circumstances surrounding the method of procurement. This hypothetical example is analogous to the findings that indicate sexual arousal in men in response to sexual scenes, regardless of whether those scenes depict mutually consenting sex or forced sex. The data do not constitute evidence that rape is a distinct evolved strategy of men.
Another possible piece of evidence for rape adaptation theory is that convicted rapists come disproportionately from lower socioeconomic groups, supporting the mate deprivation hypothesis.61 Some interviews with rapists support this view. One serial rapist, for example, reported that “I felt that my social station would make her reject me. And I didn’t feel that I would be able to make this person. I didn’t know how to go about meeting her. . . . I took advantage of her fright and raped her.”62 For men who lack the status, money, or other resources to attract women, coercion may represent a desperate alternative. Men scorned by women because they lack the qualities for attracting desirable mates may develop hostility toward women, an attitude that short-circuits the normal empathic response and so promotes coercive sexual behavior.
But this finding could also be caused by lower rates of reporting when rape is committed by men from higher social groups, or from the greater ability of privileged men to evade arrest and conviction because they can afford to hire expensive lawyers. Or perhaps women raped by high-status men are less likely to press charges, given the lower odds of being believed and obtaining justice.
There is also direct evidence against the mate deprivation hypothesis of rape. In a study of 156 heterosexual men, average age of twenty, the evolutionary psychologist Martin Lalumiere and his colleagues measured the use of sexual coercion with items such as: “Have you ever had sexual intercourse with a woman even though she didn’t really want to because you used some degree of physical force?”63 Separately, they measured mating success. Men who scored high on mating success also scored high on sexual aggression. Men who had had a lot of sexual partners were more likely to report using force. Furthermore, men who evaluated their future earning potential as high reported using more, not less, physical coercion in their mating tactics. Although additional studies are needed, we can tentatively conclude that a simple version of the mate deprivation theory of rape is unlikely to be correct.
These results, however, do not rule out a more complex hypothesis—perhaps men have evolved two kinds of context-specific rape adaptations, one contingent on when they experience mating failure and one when the costs are so low that they can get away with it, as might occur among the upper socioeconomic stratum of society.64 There is no current evidence for or against this modified hypothesis.
Rape victims tend to be disproportionately concentrated among young, reproductive-age women. Despite the fact that some women of all ages are raped, the victims of rape are heavily concentrated among young women. In one study of 10,315 rape victims, women between the ages of sixteen and thirty-five were far more likely to be raped than women in any other age category.65 Eighty-five percent of all rape victims are less than thirty-six years old. By way of comparison, victims of other crimes, such as aggravated assault and murder, show a markedly different age distribution. Women between forty and forty-nine, for example, are just as likely to suffer an aggravated assault as women between twenty and twenty-nine, but the older women are far less likely to be raped. Indeed, the age distribution of rape victims corresponds quite closely to the age distribution of women’s reproductive value, in marked contrast to the age distribution of victims of other violent crimes. This evidence strongly suggests that rape is not independent of men’s broader evolved sexual psychology.
That rapists disproportionately victimize young fertile women, however, is not decisive evidence for or against the competing theories of rape. This finding can be attributed to men’s evolved attraction to cues to fertile women in regular mating contexts rather than a rape-specific adaptation. That is, although there is abundant evidence that men are attracted to young fertile women across mating contexts, there is no evidence that this attraction is a rape-specific adaptation.
One source of evidence that many scientists believe to be relevant to theories of rape is the pregnancy rate that follows from rape. If rape evolved as a reproductive strategy, it must historically have resulted in reproduction some of the time. Modern rape-pregnancy rates, of course, are not necessarily relevant to whether rape resulted in pregnancy in the past; modern routine contraceptives may reduce current rape-pregnancy rates below those that occurred in ancestral times. Thus, it is all the more startling that one study discovered that pregnancy rates resulting from penile-vaginal rape among reproductive-age women are extraordinarily high—6.42 percent—compared to a consensual per-incident rate of only 3.1 percent.66 This finding can be partially explained by selection bias in the victims whom rapists target—young fertile women. Nonetheless, even controlling for age, the study’s authors find a rape-pregnancy rate that is roughly 2 percent higher than the consensual-sex pregnancy rate. This counterintuitive finding, if it turns out to be replicable, cries out for some kind of explanation.
Jonathan and Tiffani Gottschall offer a hypothesis anchored in the premise that men who court women using normal mating strategies are “at the mercy of discriminating females,” whereas rapists are not. Rapists, although constrained by opportunity and the defense mechanisms of women, nonetheless can and do choose victims who would otherwise refuse to mate with them. Rapists might choose women who, in addition to being young, are especially physically attractive. Since attractive women are more fertile on average (see Chapter 3), this may partially explain the unusually high rape-pregnancy rate.
The rape-pregnancy findings, however, do not directly support the rape-as-adaptation hypothesis. We already know that men are attracted to features that correlate with fertility, such as cues to youth and health, in consensual mating contexts, and so no specialized rape adaptation is required to explain these results. The rape-pregnancy findings do, however, contradict the so-called argument from inconceivable conception, according to which some opponents of the rape-as-adaptation theory claim that rape cannot possibly have evolved because it so rarely leads to conception.67
Individual men differ in their proclivity toward rape. In one study, men were asked to imagine that they had the possibility of forcing sex on someone else against her will with no chance of getting caught, no chance that anyone would find out, no risk of disease, and no possibility of damage to their reputation. Thirty-five percent indicated that there was some likelihood they would force sex on the woman under these conditions, although in most cases the likelihood was slight.68 In another study that used a similar method, 27 percent of the men indicated that there was some likelihood they would force sex on a woman if there was no chance of getting caught.69 Although these percentages are alarmingly high, if taken at face value they also indicate that most men are not potential rapists.
Men who do use coercion to get sex exhibit a distinct set of characteristics. They tend to be hostile toward women, to endorse the myth that women secretly want to be raped, and to show a personality profile marked by impulsiveness, hostility, low agreeableness, low empathy, and hypermasculinity, combined with a high degree of sexual promiscuity.70
Marital rapes are more likely when the husband is concerned about a potential sexual infidelity, as well as during or immediately following a breakup.71 This finding suggests the possibility of rape as a sperm competition adaptation. Nonetheless, the direction of causality is unclear—perhaps women are more likely to break up with partners who tend to force them into unwanted sex. In short, a conclusion reached by Donald Symons in 1979 appears to be apt today: “I do not believe that available data are even close to sufficient to warrant the conclusion that rape itself is a facultative adaptation in the human male.”72
I speculate that scientific progress will advance when theorists distinguish different types of rape, rather than viewing sexual assault as a singular crime. Consider date rape, stranger rape, warfare rape, rape by husbands, homosexual rape, and rape of stepdaughters by stepfathers. The causes of one type of rape may differ substantially from the causes of others. Date rape, for example, may be partly a by-product of the modern conditions of living, where young women live in social circumstances devoid of the close protection of extended kin—a known deterrent to violence against women. Serial stranger rapists often manage to avoid detection owing to the unusual modern conditions of high geographic mobility and anonymous urban living. The limited geographical mobility and small-group living of our ancestors would have rendered certain kinds of stranger rape virtually impossible. Rape in the context of warfare, in contrast, appears to have a cross-cultural prevalence and historical depth that may have favored selection for rape. Some kinds of rape may be caused by pathology or dysfunction of evolved mechanisms; others may be by-products; still others may be caused by specific rape adaptations. Lumping all instances of forced sex under a single label “rape” may impede progress in discovering the unique underlying causal conditions that lead to each distinct type of crime.
Do Women Have Evolved Sexual Assault Defenses?
The feminist author Susan Griffin has written: “I have never been free of the fear of rape. From a very early age, I, like most women, have thought of rape as part of my natural environment—something to be feared and prayed against like fire or lightning. I never asked why men raped; I simply thought it one of the many mysteries of human nature.”73
Although the controversy over the scientific study of rape has focused primarily on what motivates men to force sex on women, almost lost in the furor is attention to the psychology of rape victims. There is one point about victim psychology, however, on which all sides of the debate agree: rape is an abhorrent atrocity that typically inflicts heavy costs on victims. We need no formal theory to arrive at this insight. Nonetheless, it is important to determine why rape is experienced as extraordinarily traumatic.
From an evolutionary perspective, the costs of rape begin with the fact that it circumvents female choice, a core component of women’s sexual strategy. A raped woman risks untimely pregnancy with a man she has not chosen—a man who imposes himself against her will, a man who is unlikely to invest in her children, and a man who may have genes inferior to those she would otherwise have chosen. A raped woman risks being blamed, punished, or abandoned by her regular mate, who may suspect that her experience was consensual or that she somehow brought it on herself. The costs of being raped are dramatically illustrated in a case in Pakistan:
Zafran Bibi, a 26-year-old devout Muslim residing in Pakistan, was sentenced to death by stoning. Her crime was adultery, punishable by death according to Islamic law. The evidence: A child born more than a year after her husband had abandoned her, but had not yet divorced her. This was no ordinary adultery. Zafran Bibi had been raped by her brother-in-law, she testified. That did not matter. The birth of the illegitimate child proved adultery, according to the judge. Her accusation that her brother-in-law had raped her was tantamount to a criminal confession.74
Raped women suffer psychologically. They experience fear, humiliation, embarrassment, anxiety, depression, rage, and fury. They feel guilty, used, violated, and polluted. Women view forced sex as more upsetting to them than any of at least 147 other things that a man can do to hurt a woman, more upsetting even than savage nonsexual beatings at the hands of a man.75 Raped women also suffer in the aftermath. Some victims fear leaving their houses, avoid contact with men, isolate themselves socially, and live in a psychological prison with no apparent reprieve.
On top of the psychological torment, raped women suffer socially. As the case of Zafran Bibi illustrates, victims are sometimes held responsible for the crime perpetrated on them. They experience damage to their reputations. They suffer a loss in perceived desirability on the mating market. Their kin may reject or ostracize them for bringing shame on their family. They sometimes become socially shunned. Whatever the causes of rape, no one except the clueless and callused doubts the appalling damage it inflicts on the victim.
Given these often catastrophic costs, if rape has occurred throughout human history, it would defy evolutionary logic if selection had not fashioned defenses in women to prevent its occurrence. This is a separate issue from that of whether men have evolved adaptations to rape. Women could have evolved anti-rape adaptations, in principle, even if rape has been entirely a by-product of non-rape mechanisms. We can never determine with absolute certainty whether rape was frequent enough historically to have forged a female anti-rape psychology. But we can assemble available historical and cross-cultural evidence to make an educated guess. Written history dating back to the Bible brims with episodes of rape, and even specifications by religious leaders about the conditions under which men can sexually assault women. For example, the Sages of the Talmud, codified by Maimonides, provide this injunction:
A soldier in the invading army may, if overpowered by passion, cohabit with a captive woman . . . [but] he is forbidden to cohabit a second time before he marries her. . . . Coition with her is permitted only at the time when she is taken captive . . . he must not force her in the open field of battle . . . that is, he shall take her to a private place and cohabit with her.76
Although no systematic studies have been conducted on the occurrence and frequency of rape among traditional societies across cultures, an informal review of published ethnographies reveals that rape is reported in many of them—from the Amazonian jungle of Brazil to the more peaceful !Kung San of Botswana. The Semai of central Malaysia were frequently victimized by Malay raiders, who would ambush them, kill the men, and take the women by force.77 The Amazonian peoples studied by Thomas Gregor have special words for both rape (antapai) and gang rape (aintyawakakinapai).78 Rapes in war occurred as far back as there are written records, as amply documented by Susan Brownmiller in her classic treatise Against Our Will.79 Genghis Khan, more than 800 years ago, talked with relish about the gratification received through rape: “The greatest pleasure in life is to vanquish your enemies and chase them before you, to rob them of their wealth and see those dear to them bathed in tears, to ride their horses and clasp to your bosom their wives and daughters.”80 The evolutionary anthropologist Barbara Smuts summarizes the cross-cultural evidence in this way: “Although the prevalence of male violence against women varies from place to place, cross cultural surveys indicate that societies in which men rarely attack or rape women are the exception, not the norm.”81
A number of evolutionary scientists have been at the forefront in articulating potential evolved defenses against rape. Hypothesized anti-rape adaptations include:
• Psychological pain upon rape that motivates avoiding rape in the future
• Formation of alliances with males as “special friends” for protection
• Formation of female-female coalitions for protection
• Specialized fears that motivate women to avoid situations in which they might be in danger of rape
• The shunning of risky activities during ovulation to decrease the odds of sexual assault when conception is most likely
The first clue to the possibility that women have evolved adaptations to prevent being raped comes from two studies that analyzed the distribution of rapes across the female menstrual cycle. In one study of 785 rape victims, proportionately fewer women were raped during midcycle, defined as days 10 to 22 (an unfortunately wide and hence imprecise interval).82 Another study found that ovulating women were less often victims of sexual assault.83 To explore these patterns, Tara Chavanne and Gordon Gallup studied risk-taking among 300 undergraduate women.84 Women indicated whether they had engaged in each of eighteen activities that varied in their risk of making someone vulnerable to sexual assault. Going to church and watching television were examples of low-risk activities. Going to a bar and walking in a dimly lit area were examples of high-risk activities.
For women taking birth control pills, Chavanne and Gallup find no effect of menstrual cycle on risk-taking.85 Among women not taking the pill, however, ovulating women showed a decrease in risk-taking activities. Contending that risk avoidance is a candidate for an anti-rape adaptation, these authors successfully rule out several alternative explanations for the reduction in risk taking. For example, this reduction in risk taking is not a reflection of diminished sexual receptivity at ovulation; in fact, women usually peak in sexual motivation and receptivity at midcycle when they are with a consensual partner. Midcycle risk avoidance also cannot be attributed to a decrease in women’s general activity level, since pedometer-recorded activity level in women tends to increase during ovulation.86 In short, ovulating women appear to avoid behaviors that put them at increased risk of rape, suggesting the possibility of specialized risk avoidance as an anti-rape adaptation.
Many women routinely engage in risk-avoidance maneuvers to avoid putting themselves in harm’s way.87 In one study of urban women, 41 percent reported “isolation tactics,” such as not going out on the street at night, and 71 percent reported using “street-savvy tactics,” such as wearing shoes that would enable them to run away should they be attacked. In a study in Seattle, 67 percent of women said that they avoided certain dangerous locations of the city, 42 percent reported not going out unaccompanied, and 27 percent sometimes refused to answer their door. A study of Greek women reported that 71 percent avoided venturing out alone at night and 78 percent shunned dangerous locations within the city. Women also show wariness around men who talk about sex a lot, men who are sexually aggressive, and men who have a reputation for sleeping with a lot of women. Women report choosing public places for dates with men they do not know well. They intentionally avoid giving mixed sexual signals to certain men. They sometimes carry pepper spray, mace, whistles, or weapons. And they sometimes limit their drinking around men they do not know well.88
These risk avoidance strategies may be learned prudence measures, much like installing a burglar alarm after reading about a rash of burglaries in the neighborhood. Alternatively, risk avoidance may be motivated, in part, by a specialized fear of rape—a second potential anti-rape adaptation that induces women to avoid contexts conducive to sexual assault. Evidence for this specialized fear comes from a strong positive association between women’s reports of rape-fear and their reports of how many different behavioral precautions they take to avoid rape.89 Women who are fearful of rape, more than women who are less fearful, avoid being alone with men they do not know well, decline rides from men, leave when a man comes on too strong sexually, avoid outdoor activities when alone, and exercise caution in their drinking. One New Zealand study found that young women experience more fear of sexual assault than older women; older women’s fears were more likely to center on being robbed or burgled than on being raped.90 Women residing in neighborhoods with a high incidence of rape report more fear than those living in safer neighborhoods. These studies, of course, cannot determine whether women have evolved a specialized fear of rape contingent on their age and vulnerability, or whether these fears are expressions of more general mechanisms such as a rational appraisal of danger combined with fear mechanisms possessed by all people.
The psychologists Susan Hickman and Charlene Muehlenhard found that women were more fearful of being raped by strangers than by acquaintances. This difference occurred despite the fact that stranger rape is rare, accounting for only 10 to 20 percent of all rapes, compared with acquaintance rape, which is far more common, roughly 80 to 90 percent.91 Hickman and Muehlenhard conclude that women’s fears do not match the realities of rape. An alternative interpretation is that women’s apprehensions are actually effective: stranger fear motivates precautionary behaviors, lowering the real incidence of stranger rape below what it would have been without these functional fears. According to this view, women’s stranger fears function to prevent rape. Alternatively, women’s fear of stranger rape could have evolved in ancestral environments in warfare contexts in which rapists were, in fact, mostly strangers—very much unlike the modern environment. These hypotheses could both be partially true, and both remain to be empirically tested.
Sarah Mesnick and Margo Wilson have explored a third potential anti-rape adaptation, which they call the bodyguard hypothesis. According to this hypothesis, women form heterosexual pair-bonds with men in part to reduce their risk of sexual aggression from other men.92 According to the bodyguard hypothesis, women should be especially attracted to physically large and socially dominant men in contexts in which they are at risk of sexual aggression. To test the bodyguard hypothesis, Wilson and Mesnick studied 12,252 women, each interviewed over the phone by trained female interviewers. Questions about sexual assault began with: “Has a male stranger ever forced you or attempted to force you into any sexual activity by threatening you, holding you down or hurting you in some way?” Subsequent questions dealt with unwanted sexual touching: “[Apart from this incident you have just told me about], has a male stranger ever touched you against your will in any sexual way, such as unwanted touching, grabbing, kissing, or fondling?”93 The statistical analyses focused on sexual victimizations that had occurred within the twelve months prior to the interview and excluded sexual assaults by husbands or boyfriends.
A total of 410 unmarried and 258 married women reported experiencing one or more of these sexual violations. Marital status proved to have a dramatic effect on sexual victimization. Among women in the youngest age bracket of eighteen to twenty-four, eighteen out of one hundred unmarried women reported sexual victimization by a stranger, whereas only seven out of every one hundred married women reported sexual victimization. Messick and Wilson conclude that their results support the bodyguard hypothesis, although they acknowledge that they have not identified the causal mechanism by which married women are less likely to be raped than comparably aged single women. The lower rape rates among married than single women might reflect lifestyle differences—single women might spend more time in public places, such as bars and parties where alcohol is consumed, rather than at home, making them more vulnerable to predatory rapists. It might reflect individual differences in mating strategies, whereby single women might be more likely to pursue short-term matings that place them in contexts where they are exposed to greater danger of sexual coercion. Or it might reflect the deterrent effects of husbands on potential rapists, as the bodyguard hypothesis suggests. The bodyguard hypothesis requires more direct tests: Are women especially likely to choose large, physically imposing men when living in social circumstances that indicate a relatively higher risk of rape? Are women with such men for partners less likely to be raped than women with less formidable partners? Although one study found that women put in crime-prone areas of a city ramp up their preferences for physically formidable mates, this shift appears to reflect a general anticrime protective reaction rather than a rape-specific defense.94
A fourth hypothesized anti-rape adaptation is specialized psychological pain, articulated in Thornhill and Palmer’s A Natural History of Rape.95 According to this hypothesis, the psychological trauma that women experience from rape motivates them to avoid similar recurrences in the future. Evidence for this hypothesis comes from a study that purports to show that the women who experience the most intense pain and psychological trauma from rape are (a) young and fertile women rather than prepubescent girls or postmenopausal women, (b) married rather than single women, and (c) victims who were vaginally raped rather than orally or anally raped. Furthermore, (d) women who experience the most visible signs of physical violence during rape experience the least psychological pain, presumably because they would be less likely to be blamed for or suspected of complicity in the rape. An advocate of the psychological pain hypothesis might have added an additional prediction—(e) that women raped by men low in mate value (for example, men who are unattractive and of low socioeconomic status) will experience more psychological trauma than women raped by men higher in mate value (more attractive and higher-status men).
Regardless of these points of theoretical and empirical contention, one thing is quite clear—sound scientific evidence is lacking on the specifics of women’s defenses against rape. Research is urgently needed on women’s anti-rape strategies and their relative effectiveness, whether or not such strategies ultimately turn out to be specialized evolved adaptations or products of more general cognitive and emotional mechanisms.
The Evolutionary Arms Race
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, to sexual harassment in the workplace, date rape, and warfare rape. Even taking into account the many scientific questions that still remain about how best to explain rape, 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.
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.
These battles create spiraling arms races over evolutionary time. For every incremental gain in men’s ability to deceive women, women evolve comparable incremental gains in their ability to detect deception. Better abilities to detect deception, in turn, create the evolutionary conditions for the other sex to develop increasingly subtle forms of deception. 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.
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.