Women's Long-Term Mating Strategies PDF

ChaPter 4 Women’s Long-Term Mating Strategies Learning Objectives Afer studying this chapter, the reader will be able to: ■ Explain the two major components of sexual selection theory. ■ Explain parental investment theory and analyze how parental investment infuences the components of sexual sel...

ChaPter 4 Women’s Long-Term Mating Strategies Learning Objectives Afer studying this chapter, the reader will be able to: ■ Explain the two major components of sexual selection theory. ■ Explain parental investment theory and analyze how parental investment infuences the components of sexual selection. ■ analyze the multiple adaptive problems potentially solved by women’s preferences for men with resources. ■ Evaluate why women have an evolved mate preference for cues to athletic ability. ■ summarize the evidence for the efects of women’s personal resources on their mate preferences. ■ Explain “mate copying” and provide one example from real life. ■ identify four fndings that illustrate how women’s mate preferences infuence actual mating behavior. Nowhere do people have an equal desire for all potential mates. Everywhere, some potential mates are preferred, others shunned. Imagine living as our ancestors did long ago—struggling to keep warm by the fre; hunting meat for our kin; gathering nuts, berries, and herbs; and avoiding dangerous animals and hostile humans. If we were to select a mate who failed to deliver the resources promised, who had afairs, who was lazy, who lacked hunting skills, or who heaped physical abuse on us, our survival would be tenuous, our reproduction at risk. In contrast, a mate who provided abundant resources, who protected us and our children, and who devoted time, energy, and efort to our family would be a great asset. As a result of the powerful survival and reproductive advantages reaped by those of our ancestors who chose mates wisely, many specifc desires evolved. As descendants of those winners in the evolutionary lottery, modern humans have inherited a specifc set of mate preferences. Scientists have documented evolved mate preferences in many non-human species. The African village weaverbird provides a vivid illustration (Collias & Collias, 1970). When a female weaverbird arrives in the vicinity of a male, he displays his recently built nest by suspending himself upside down from the bottom and vigorously fapping his wings. If the male impresses the female, she approaches the nest, enters it, and examines the nest materials, poking and pulling them for as long as 10 minutes. During this inspection, the male sings to her from nearby. At any point in this sequence, she may decide that the nest does not meet her standards and depart to inspect another male’s nest. A male whose nest is rejected by several females will often break it down and rebuild another from scratch. By exerting a preference for males capable of building superior nests, the female weaverbird addresses the problems of protecting and provisioning her chicks. Her preferences have evolved because they bestowed a reproductive advantage over other weaverbirds who had no preferences and who mated with any male who happened to come along. Women, like weaverbirds, also prefer males with “nests” of various kinds. Consider one of the problems that women in evolutionary history had to face: selecting a man who would be willing to commit to a long-term relationship. A woman in our evolutionary past who chose to ChALLENGES OF SEx AND MATiNG 102 mate with a man who was fighty, impulsive, philandering, or unable to sustain a relationship found herself raising her children alone and without beneft of the resources, aid, and protection that a more dependable mate might have ofered. A woman who preferred to mate with a reliable man who was willing to commit to her would have had children who survived, thrived, and multiplied. Over thousands of generations, a preference for men who showed signs of being willing and able to commit evolved in women, just as preferences for mates with adequate nests evolved in weaverbirds. Theoretical Background for the Evolution of Mate Preferences This section reviews two important theoretical issues that are key to understanding the evolution of mate preferences. The frst deals with the defnition of the two distinct types that exist in sexually reproducing species—males and females—and the related issue of the infuence of parental investment on the nature of mating. The second topic pertains to mate preferences as evolved psychological mechanisms. Parental Investment and Sexual Selection It is a remarkable fact that what defnes biological sex is simply the size of the sex cells. Mature reproductive cells are called gametes. Each gamete has the potential to fuse with another gamete of the opposite sex to form a zygote, which is defned as a fertilized gamete. Males are the sex with the small gametes, females the large gametes. The female gametes remain reasonably stationary and come loaded with nutrients; the male gametes are endowed with greater mobility. Along with diferences in size and mobility comes a diference in quantity. Men produce millions of sperm, which are replenished at a rate of roughly 12 million per hour. Women, on the other hand, produce a fxed and unreplenishable lifetime supply of eggs, of which perhaps a few hundred will be ovulated during the lifetime. Women’s greater initial investment per gamete does not end with the egg. Fertilization and gestation, key components of human parental investment, occur internally in women. One act of sexual intercourse that requires minimal male investment can produce an obligatory and energyconsuming 9-month investment by the woman. In addition, women alone engage in the activity of lactation (breastfeeding), which lasts as long as 4 years in some societies (Shostak, 1981). No biological law of the animal world dictates that females must invest more than males. Indeed, in some species such as the Mormon cricket, pipefsh seahorse, and Panamanian poison arrow frog, males in fact invest more (Trivers, 1985). The male Mormon cricket produces a large spermatophore that is loaded with nutrients. Females compete with each other for access to the high-investing males holding the largest spermatophores. Among these so-called sex-rolereversed species, males are more discriminating than females about mating. In particular, the females chosen by the males for depositing their spermatophore contain 60 percent more eggs than females who are rejected (Trivers, 1985). Among all 5,000 species of mammals and the 300 species of primates, however, the females—not the males—undergo internal fertilization and gestation. The great initial parental investment of females makes them a valuable reproductive resource (Trivers, 1972). Gestating, bearing, lactating, nurturing, protecting, and feeding a child are exceptionally valuable reproductive resources. Those who hold valuable resources do not give them away haphazardly. Because women in our evolutionary past risked investing enormously as a consequence of having sex, evolution favored women who were highly selective about their mates. Ancestral women sufered severe costs if they were indiscriminate: They experienced lower reproductive success, and fewer of their children survived to reproductive age. 4 WOMEN’S LONG-TERM MATiNG STRATEGiES In summary, Trivers’s (1972) theory of parental investment and sexual selection makes two profound predictions: (1) The sex that invests more in ofspring (typically, but not always, the female) will be more discriminating or selective about mating; and (2) the sex that invests less in ofspring will be more competitive for sexual access to the high-investing sex. In the case of humans, it is clear that women have greater obligatory parental investment. For longterm mating or marriage, however, both men and women typically invest heavily in children, and so the theory of parental investment predicts that both sexes should be very choosy and discriminating. Mate Preferences as Evolved Psychological Mechanisms Consider the case of an ancestral woman trying to decide between two men, one of whom shows great generosity to her with his resources and the other of whom is stingy. All else being equal, the generous man is more valuable to her than the stingy man. The generous man may share his meat from the hunt, aiding her survival. He may sacrifce his time, energy, and resources for the beneft of the children, aiding the woman’s reproductive success. In these respects, the generous man has higher value than the stingy man as a mate. If, over evolutionary time, generosity in men provided these benefts repeatedly and the cues to a man’s generosity were observable and reliable, selection could favor the evolution of a preference for generosity in a mate, especially if that generosity got directed specifcally to the woman doing the mate selection. Now consider a more complicated and realistic scenario in which men vary not just in their generosity but also in a bewildering variety of ways that are signifcant in the choice of a mate. Men difer in their physical prowess, athletic skill, ambition, industriousness, kindness, empathy, emotional stability, intelligence, social skills, sense of humor, kin network, and position in the status hierarchy. Men also difer in the costs they carry into a mating relationship: some come with children, a bad temper, a selfsh disposition, and promiscuous proclivities. In addition, men difer in hundreds of ways that may be irrelevant to women. From among the thousands of ways in which men difer, selection over hundreds of thousands of years focused women’s preferences, laser-like, on the most adaptively valuable characteristics. Women lacking specifc adaptively relevant preferences are not our ancestors; they were out-reproduced by choosier women. The qualities people prefer, however, are not static. Because preferences change over time, mate seekers must gauge the future potential of a prospective partner. A man might lack resources now but, as a medical student, might have excellent future promise. Gauging a man’s mate value requires looking beyond his current position and evaluating his future potential. In short, evolution has favored women who prefer men possessing attributes that confer benefts and who dislike men possessing attributes that impose costs. Each separate attribute constitutes one component of a man’s value to a woman as a mate. Each of her preferences tracks one critical component. Preferences that give priority to particular components, however, do not completely solve the problem of choosing a mate. In selecting a mate, a woman must deal with the problem of identifying and correctly evaluating the cues that signal whether a man actually possesses a particular quality. The assessment problem becomes especially acute in areas in which men are apt to deceive women, such as pretending greater status than they actually possess or feigning greater commitment than they are truly willing to give. Women also face the problem of integrating their knowledge about a prospective mate. Suppose that one man is generous but emotionally unstable. Another man is emotionally stable but stingy. Which man should a woman choose? Selecting a mate requires psychological mechanisms that make it possible to add up the relevant attributes and give each an appropriate weight to the fnal decision. Some attributes weigh more than others in arriving at the fnal decision about whether to choose or reject a particular man. Finally, wise women seek mates in their own mate-value range. Trying to attract a “10” if you are only an “8” is risky; even if 103 ChALLENGES OF SEx AND MATiNG 104 successful in the initial attraction stage, over time, the higher-mate-value partner is more likely to abandon the lower-mate-value partner. The Content of Women’s Mate Preferences With this theoretical background in mind, we turn now to the actual content of women’s mate preferences (summarized in Table 4.1). As the previous discussion implies, choosing a mate is a complex task, and so we do not expect to fnd simple answers to what women want. Preference for Economic Resources The evolution of the female preference for males ofering resources may be the most ancient and pervasive basis for female choice in the animal kingdom. Consider the grey shrike, a bird living in the Negev desert of Israel (Yosef, 1991). Just before the start of the breeding season, male shrikes begin amassing caches of edible prey such as snails and useful objects such as feathers and pieces of cloth in numbers ranging from 90 to 120. They impale these items on thorns and other pointed projections within their territories. Females scan the available males and choose to mate with those with the largest caches. When Yosef arbitrarily removed portions of some males’ stock and added edible objects to the supplies of others, females preferred to mate with the males with the larger bounties. Females entirely avoided males without resources, consigning them to bachelorhood. Table 4.1 Adaptive Problems in Long-Term Mating and Hypothesized Solutions adaptive Problem evolved Mate Preference Selecting a mate who is able to invest Good fnancial prospects Social status Slightly older age Ambition/industriousness Size, strength, and athletic ability Dependability and stability Love and commitment cues Positive interactions with children Size (height) Bravery Athletic ability Masculine body type Dependability Emotional stability Kindness Positive interactions with children Similar values Similar ages Similar personalities Physical attractiveness Symmetry Health Masculine features Selecting a mate who is willing to invest Selecting a mate who is able to physically protect her and children Selecting a mate who will show good parenting skills Selecting a mate who is compatible Selecting a mate who is healthy 4 WOMEN’S LONG-TERM MATiNG STRATEGiES Among humans, the evolution of women’s preference for a long-term mate with resources would have required two preconditions. First, resources would have to be accruable, defensible, and controllable by men during human evolutionary history. Second, men would have to difer from each other in their holdings and their willingness to invest those holdings in a woman and her children. Over the course of human evolutionary history, some women could garner more resources for their children through a single spouse than through several casual sex partners. Men invest in their wives and children with provisions to an extent unprecedented among primates. In all other primates, females must rely solely on their own eforts to acquire food because males rarely share those resources with their mates (Smuts, 1995). Men, in contrast, provide food, fnd shelter, defend territory, and protect children. They tutor children in sports, hunting, fghting, hierarchy negotiation, friendship, and social infuence. They transfer status, aiding ofspring in forming reciprocal alliances later in life. These benefts are unlikely to be secured by a woman from a casual sex partner, although some women develop “special friendships” with men that may ofer protection and resources during times of need or serve as “backup” mates should something happen to their regular mate (Buss, Goetz, Duntley, Asao, ConroyBeam, 2017; Smuts, 1985). So the stage was set for the evolution of women’s preferences for men with resources. But women needed cues to signal a man’s possession of those resources. These cues might be indirect, such as personality characteristics that signal a man’s upward mobility. They might be physical, such as a man’s athletic ability or health. They might include reputation, such as the esteem in which a man is held by his peers. The possession of economic resources, however, provides the most obvious cue. Preference for Good Financial Prospects Currently held mate preferences provide a window for viewing our mating past, just as our fears of snakes and heights provide a window for viewing ancestral hazards. Evidence from dozens of studies documents that modern U.S. women indeed value economic resources in mates substantially more than men do. In a study conducted in 1939, for example, U.S. men and women rated 18 characteristics for their relative desirability in a marriage partner, ranging from irrelevant to indispensable. Women did not view good fnancial prospects as absolutely indispensable, but they did rate them as important, whereas men rated them as merely desirable but not very important. Women in 1939 valued good fnancial prospects in a mate about twice as highly as men did, a fnding that was replicated in 1956 and again in 1967 (Buss, Shackelford, Kirkpatrick, & Larsen, 2001). Douglas Kenrick and his colleagues devised a useful method for revealing how much people value diferent attributes in a marriage partner by having men and women indicate the “minimum percentiles” of each characteristic they would fnd acceptable (Kenrick, Sadalla, Groth, & Trost, 1990). U.S. college women indicate that their minimum acceptable percentile for a husband on earning capacity is the 70th percentile, or above 70 percent of all other men, whereas men’s minimum acceptable percentile for a wife’s earning capacity is only the 40th. Personal ads in newspapers and online dating sites confrm that women who are actually in the marriage market desire strong fnancial resources (Gustavsson & Johnsson, 2008; Wiederman, 1993). In short, sex diferences in preference for resources are not limited to college students and are not bound by the method of inquiry. Nor are these female preferences restricted to America, to Western societies, or to capitalist countries. A large cross-cultural study was conducted of 37 cultures on six continents and fve islands using populations ranging from coast-dwelling Australians to urban Brazilians to shantytown South African Zulus (Buss et al., 1990). Some participants came from nations that practice polygyny (the mating or marriage of a single man with several women), such 105 106 ChALLENGES OF SEx AND MATiNG as Nigeria and Zambia. Other participants came from nations that are more monogamous (the mating of one man with one woman), such as Spain and Canada. The countries included those in which living together is as common as marriage, such as Sweden and Finland, as well as countries in which living together without marriage is frowned on, such as Bulgaria and Greece. The study sampled a total of 10,047 individuals in 37 cultures, as shown in Figure 4.1 (Buss, 1989a). Male and female participants rated the importance of 18 characteristics in a potential mate or marriage partner, on a scale from unimportant to indispensable. Women across all continents, all political systems (including socialism and communism), all racial groups, all religious groups, and all systems of mating (from intense polygyny to presumptive monogamy), placed more value than men on good fnancial prospects. Overall, women valued fnancial resources roughly twice as much as did men (see Figure 4.2). There are some cultural variations. Women from Nigeria, Zambia, India, Indonesia, Iran, Japan, Taiwan, Colombia, and Venezuela valued good fnancial prospects a bit higher than women from South Africa (Zulus), the Netherlands, and Finland. In Japan, for example, women valued good fnancial prospect roughly 150 percent more than men, whereas women from the Netherlands deem it only 36 percent more important than their male counterparts, less than women from any other country. Nonetheless, the sex diference remained invariant: Women worldwide desired fnancial resources in a marriage partner more than men. Figure 4.1 Locations of 37 Cultures Studied in an International Mate Selection Project Source: Buss, D. M. (1994a). The strategies of human mating. American Scientist, 82, 238–249. Reprinted with permission. Figure 4.2 Preference for Good Financial Prospect in a Marriage Partner N = sample size. p values less than .05 indicate that sex diference is signifcant. Source: Buss, D. M., & Schmitt, D. P. (1993). Sexual strategies theory: An evolutionary perspective on human mating. Psychological Review, 100, 204–232. Copyright © 1993 by the American Psychological Association. Adapted with permission. 4 WOMEN’S LONG-TERM MATiNG STRATEGiES Thirty-seven cultures, distributed as shown, were examined by the author in his international study of male and female mating preferences. The author and his colleagues surveyed the mating desires of 10,047 people on six continents and fve islands. The results provide the largest database of human mating preferences ever accumulated. Participants in cultures rated this variable, in the context of 17 other variables, on how desirable it would be in a potential long-term mate or marriage partner using a four-point rating scale, ranging from 0 (irrelevant or unimportant) to 3 (indispensable). These fndings provided the frst extensive cross-cultural evidence supporting the evolutionary basis for the psychology of human mating. Since that study, fndings from other cultures continue to support the hypothesis that women have evolved preferences for men with resources. One massive study of 21,245 Germans ranging in age from 18 to 65 found that the largest sex diference centered on women’s greater preference for “wealthy and generous” (Schwarz & Hassebrauck, 2013). A study of the Himba, a small group of seminomadic pastoralists living in northwest Namibia, found that women prioritize long-term mates who are wealthy, respectful, hardworking, and generous—key cues to the ability and willingness of a man to acquire and share resources (Scelza & Prall, 2018). A study of Chinese, European, and American individuals found that a potential mate’s salary had four times the impact on women’s judgments of men’s attractiveness compared to men’s judgments of women’s attractiveness (Wang et al., 2018). Another study found that women experienced relationship regret over getting involved with a man who was “stingy” and passing up on an opportunity to get involved with a man who was “wealthy” (Coats, Harrington, Beaubouef, & Locke, 2011). A study of mate selection in the country of Jordan found that women more than men valued economic ability, as well as qualities linked to economic ability such as status, ambition, and education (Khallad, 2005). Using a diferent method—analysis of folktales in 48 cultural areas including bands, tribes, preindustrial states, Pacifc islands, and all the major continents—Jonathan Gottschall and colleagues found the same sex diference (Gottschall et al., 2003). Substantially more female than male characters in the folktales from each culture placed a primary emphasis on wealth or status in their expressed mate preferences. Gottschall found similar results in a historical analysis of European literature (Gottschall, Martin, Quish, & Rea, 2004). A study of 500 Muslims living in the United States found that women sought fnancially secure, emotionally sensitive, and sincere partners, the latter being a signal of willingness to commit to a long-term relationship (Badahdah & Tiemann, 2005). Finally, an in-depth study of the Hadza of Tanzania, a hunter-gatherer society, found that women place a great importance on a man’s foraging abilities—primarily his ability to hunt and provide meat (Marlowe, 2004). This fundamental sex diference also appears prominently in modern forms of mating, such as speed dating and mail-order brides. In a study of speed dating, in which individuals engage in 4-minute conversations to determine whether they are interested in meeting the other person again, women chose men who indicated that they had grown up in afuent neighborhoods (Fisman, Iyengar, Kamenica, & Simonson, 2006). Another study of a community sample of 382 speed daters, ranging in age from 18 to 54, found that women’s choices, more than men’s choices, were infuenced by a potential date’s income and education (Asendorpf, Penke, & Back, 2011). A study of the mate preferences of mail-order brides from Colombia, the Philippines, and Russia found that these women sought husbands who had status and ambition—two key correlates of resource acquisition (Minervini & McAndrew, 2006). As the authors conclude, “women willing to become MOBs [mail-order brides] do not appear to have a diferent agenda than other mate-seeking women; they simply have discovered a novel way to expand their pool of prospective husbands” (2006, p. 17). A study of personal advertisements in Sweden, a culture that has a high level of economic equality between the sexes, found that women sought resources 107 ChALLENGES OF SEx AND MATiNG 108 three times as often as did men (Gustavsson & Johnsson, 2008). A study of 2,956 Israelis who subscribed to a computer dating service found that women, far more than men, sought mates who owned their own cars, had good economic standing, and placed a high level of importance on their careers (Bokek-Cohen, Peres, & Kanazawa, 2007). Women also place tremendous value on intelligence in a long-term mate (Buss et al., 1990; Prokosch, Coss, Scheib, & Blozis, 2009), a quality highly predictive of income and occupational status (Buss, 1994b). Even in more traditional societies, such as the Kipsigis of Kenya, women (as well as the women’s parents when choosing for them) preferentially select men who have resources such as large plots of land (Borgerhof Mulder, 1990). Finally, a study of the reproductive outcomes of women living in preindustrial Finland in the 18th and 19th centuries found that women married to wealthier men had higher survival rates and a larger number of children who survived to adulthood than women married to poorer men (Pettay, Helle, Jokela, & Lummaa, 2007). A historical study of Norwegians found similar efects (Skjærvø, Bongard, Viken, Stokke, & Røskaft, 2011). The enormous body of empirical evidence across diferent methods, time periods, and cultures supports the hypothesis that women have evolved a powerful preference for long-term mates with the ability to provide resources. Today’s women are the descendants of a long line of women who had these mate preferences—preferences that helped them to solve the adaptive problems of survival and reproduction. Preference for High Social Status Traditional hunter-gatherer societies, one rough guide to what ancestral conditions were probably like, suggest that ancestral men had clearly defned status hierarchies. Resources in most status hierarchies fow freely to those at the top and trickle slowly to those at the bottom (Betzig, 1986; Brown & Chia-Yun, n.d.). Cross-culturally, groups such as the Melanesians, the early Egyptians, the Sumerians, the Japanese, and the Indonesians include people described as “head men” and “big men” who wield great power and enjoy the resource privileges of prestige. Among various south Asian languages, for example, the term “big man” is found in Sanskrit, Hindi, and several Dravidian languages. In Hindi, for example, bara asami means great man or someone high in rank (Platts, 1960). In North America, “big man” and similar terms are found among groups such as the Wappo, Dakota, Miwok, Natick, Choctaw, Kiowa, and Osage. In Mexico and South America, “big man” and closely related terms are found among the Cayapa, Chatino, Mazahua, Mixe, Mixteco, Quiche, Terraba, Tzeltal, Totonaca, Tarahumara, Quechua, and Hahuatl. In language, therefore, many cultures have found it important to invent words or phrases to describe men who are high in status. Women desire men who command a high position because social status is a universal cue to the control of resources. Along with status come better food, more abundant territory, and superior health care. Greater social status bestows on children social opportunities missed by the children of lower-ranking males. For male children worldwide, access to more and better-quality mates typically accompanies families of higher social status. In one study of 186 societies ranging from the Mbuti Pygmies of Africa to the Aleut of Alaska, high-status men invariably had greater wealth and more wives and provided better nourishment for their children (Betzig, 1986). One study examined short-term and long-term mating to discover which characteristics people especially valued in potential spouses, as contrasted with potential sex partners (Buss & Schmitt, 1993). Several hundred individuals evaluated 67 characteristics for their desirability or undesirability in the short or long term, rating them on a scale ranging from −3 (extremely undesirable) to +3 (extremely desirable). Women judged the likelihood of success in a profession and the possession of a promising career to be highly desirable in a spouse, giving average ratings 4 WOMEN’S LONG-TERM MATiNG STRATEGiES 109 Figure 4.3 Preference for Social Status in a Marriage Partner N = sample size. p values less than .05 indicate that sex diference is signifcant. NS indicates that sex diference is not signifcant. Source: Buss, D. M., Abbott, M., Angleitner, A., Asherian, A., Biaggio, A. et al. (1990). International preferences in selecting mates: A study of 37 cultures. Journal of Cross-Cultural Psychology, 21, 5–47. Participants in 37 cultures rated this variable, in the context of 18 other variables, on how desirable it would be in a potential long-term mate or marriage partner using a four-point rating scale, ranging from 0 (irrelevant or unimportant) to 3 (indispensable). of +2.60 and +2.70, respectively. Importantly, these cues to future status are seen by women as more desirable in spouses than in casual sex partners. U.S. women also place great value on education and professional degrees in mates—characteristics that are strongly linked with social status. The importance that women grant to social status in mates is not limited to the United States or even to capitalist countries. In the vast majority of the 37 cultures considered in the international study on choosing a mate, women valued social status in a prospective mate more than men in both communist and socialist countries, among Africans and Asians, among Catholics and Jews, in the southern tropics and the northern climes (Buss, 1989a). In Taiwan, for example, women valued status 63 percent more than men; in West Germany, women valued it 38 percent more; and in Brazil, women valued it 40 percent more (see Figure 4.3). Another study conducted in Iran found that a preference for a combined “status-resources” factor showed the largest gender diference of all in long-term mate preferences (Atari, 2017). Women appear to have solved the adaptive problem of acquiring resources in part by preferring men who are high in status. Indeed, when forced to trade of among diferent mate characteristics, women prioritize social status, viewing it as a “necessity” rather than a “luxury” (Li, 2007). Women evaluate men who possess high-status items such as luxury high-prestige cars and luxury apartments as especially attractive potential partners (Dunn & Hill, 2014; Dunn & Searle, 2010). Preference for Somewhat Older Men The age of a man also provides an important clue to his access to resources. Just as young male baboons must mature before they are able to enter the upper ranks in the baboon social hierarchy, human adolescents rarely command the respect, status, or position of more mature men. Older men have had more time to build important alliances, cultivate skills, and learn more about the environment—all benefcial attributes. The age–resources link reaches extremes among the Tiwi, an aboriginal tribe located on two islands of the coast of northern Australia (Hart & Pilling, 1960). The Tiwi are a gerontocracy in which the very old men wield most of the power and prestige; they control the mating system through complex social alliances. Even in U.S. culture, status and wealth tend to accumulate with increasing age. ChALLENGES OF SEx AND MATiNG 110 In all 37 cultures included in the international study on mate selection, women preferred older men (see Figure 4.4). Averaged over all cultures, women prefer men who are roughly 3.5 years older. Another study of 22,400 individuals in 14 diferent cultures and two diferent religious groups (Muslims and Christians) found similar results (Dunn, Brinton, & Clark, 2010). The preferred age diference ranges from French Canadian women, who seek husbands just a shade under 2 years older, to Iranian women, who seek husbands more than 5 years older. Why do women prefer somewhat older men, but not much older men? The answer seems to lie partially in problems that develop in much older men—they are more likely to be infertile, women who get pregnant with them are more likely to experience pregnancy problems, and children of much older men are at increased risk of genetic abnormalities (Spinelli, Hattori, & Sousa, 2010). Much older men also are less likely to live a long time—they have a shorter shelf-life ahead of them—so have fewer years of investment from which a woman might beneft. To understand why women value somewhat older mates, we must consider the things that change with age. One of the most consistent changes is access to resources. In contemporary Western societies, income generally increases with age (Jencks, 1979). These status trends are not limited to the Western world. Among the Tiwi, a polygynous people, men are typically at least 30 before they have enough social status to acquire a frst wife (Hart & Pilling, 1960). Rarely does a Tiwi man under the age of 40 attain enough status to acquire more than one wife. Older age, resources, and status are coupled across cultures. In traditional societies, part of this linkage may be related to physical strength and hunting prowess. Physical strength increases in men as they get older, peaking in the late 20s and early 30s. In traditional hunter-gatherer societies such as the Tsimane Amerindians of the Bolivian Amazon and the Inuit of the Canadian Arctic, hunting skill peaks even later—roughly the mid- to late 30s (Collings, 2009; Gurven, Kaplan, & Gutierrex, 2006). A study of a small-scale Amazonian society in Ecuador found that a man’s hunting ability was the strongest predictor of women’s judgments of a man’s attractiveness, closely followed by a man’s status and reputation as a good warrior (Escasa, Gray, & Patton, 2010). So women’s preference for somewhat older men may stem from our hunter-gatherer ancestors, for whom the resources derived from hunting were critical to survival. Importantly, older men will have had more time to build important social alliances and acquire status—qualities directly benefcial to a woman and her children that can aid in their survival and their future mating opportunities. Preference for Ambition and Industriousness How do people get ahead in everyday life? Among all the tactics, sheer hard work proves to be one of the best predictors of past and anticipated income and promotions. Those who work hard achieve higher levels of education and status, higher annual salaries, and more promotions than their more laid-back peers. Industrious and ambitious men secure a higher occupational status than lazy, unmotivated men (Jencks, 1979; Kyl-Heku & Buss, 1996; Lund, Tamnes, Moestue, Buss, & Vollrath, 2007; Willerman, 1979). In the overwhelming majority of cultures, women value ambition and industriousness more than men do, typically rating them as between important and indispensable. In Taiwan, for example, women rate ambition and industriousness as 26 percent more important than men do, women 4 WOMEN’S LONG-TERM MATiNG STRATEGiES 111 Figure 4.4 Age Diferences Preferred between Self and Spouse N = sample size. Source: Buss, D. M., & Schmitt, D. P. (1993). Sexual strategies theory: An evolutionary perspective on human mating. Psychological Review, 100, 204–232. Copyright © 1993 by the American Psychological Association. Adapted with permission. Participants recorded their preferred age diference, if any, between self and potential spouse. The scale shown is in years, with positive values signifying preference for older spouses and negative values signifying preference for younger spouses. from Bulgaria rate it as 29 percent more important, and women from Brazil rate it as 30 percent more important. This cross-cultural and cross-historical evidence supports the key evolutionary psychological prediction that women have evolved a preference for men possessing signs of the ability to acquire resources and are less attracted to men lacking the ambition that often leads to status and resources. Preference for Dependability and Stability Among the 18 characteristics rated in the worldwide study on mate selection, the second- and third-most-highly-valued characteristics are a dependable character and emotional stability or maturity. In 21 of 37 cultures, men and women had the same preference for dependability in a partner (Buss et al., 1990). Of the remaining 16 cultures, women in 15 valued dependability more than men. Averaged across all 37 cultures, women rated dependable character a 2.69, where a 3 signifes indispensable; men rate it nearly as important, with an average of 2.50. In the case of emotional stability or maturity, the sexes difer more. Women in 23 cultures value this quality signifcantly more than men do; in the remaining 14 cultures, men and women value emotional stability equally. Averaging across all cultures, women give this quality a 2.68, whereas men give it a 2.47. These characteristics may possess great value to women worldwide for two reasons. First, they are reliable signals that resources will be provided consistently over time. Second, men who lack dependability and emotional stability provide erratically and infict heavy emotional and other costs on their mates (Buss, 1991). They tend to be self-centered and monopolize shared resources. They are frequently possessive, monopolizing much of the time of their wives. They show higher-than-average sexual jealousy, becoming enraged when their wives merely talk with someone else. They tend to be dependent, insisting that their mates provide for all of their 112 ChALLENGES OF SEx AND MATiNG needs. They tend to be verbally and physically abusive. They have more afairs than average, suggesting further diversion of time and resources (Buss & Shackelford, 1997a). All these costs reveal that undependable and emotionally unstable men will absorb their partners’ time and resources, divert their own time and resources elsewhere, and fail to channel resources consistently over time. Dependability and stability are personal qualities that signal increased likelihood that a woman’s own resources will not be drained by the man. Unpredictability interferes with solutions to critical adaptive problems. The erratic supply of resources can wreak havoc with accomplishing the goals required for survival and reproduction. Meat that is suddenly not available because an unpredictable, changeable, or variable mate decided at the last minute to take a nap rather than go on the hunt is sustenance counted on but not delivered. Resources that are supplied predictably can be more efciently allocated to Women prefer men who are relatively tall, athletic, muscular, and the many adaptive hurdles that must display a V-shaped torso, with shoulders broader than hips—signals that be overcome in everyday life. Women indicate a man’s ability to protect a woman and her children. place a premium on dependability and emotional stability to reap the benefts that a mate can provide to them consistently over time. Preference for Athletic Prowess, Formidability, and Height The importance of physical characteristics in the female choice of a mate is notable throughout the animal world. Male gladiator frogs are responsible for creating nests and defending the eggs. In the majority of courtships, a stationary male gladiator frog is deliberately bumped by a female who is considering him. She strikes him with great force, sometimes enough to rock him back or even scare him away. If the male moves too much or bolts from the nest, the female hastily leaves to fnd an alternative mate. Bumping helps a female frog assess how successful the male will be at defending her clutch. The bump test reveals the male’s physical ability to protect. Women sometimes face physical domination by larger, stronger males, which can lead to injury and sexual domination. These conditions undoubtedly occurred with some regularity during ancestral conditions. Studies of many non-human primate groups reveal that male physical and sexual domination of females has been a recurrent part of our primate heritage. Primatologist Barbara Smuts lived among the baboons residing in the savanna plains of Africa and studied their mating patterns (Smuts, 1985). She found that females frequently formed enduring “special friendships” with males who ofered physical protection to them and their infants. In return, these females sometimes granted their “friends” preferential mating access during times of estrus. 4 WOMEN’S LONG-TERM MATiNG STRATEGiES One beneft to women of long-term mating is the physical protection a man can ofer. A man’s size, strength, physical prowess, and athletic ability are cues that signal solutions to the problem of protection. Evidence shows that women’s preferences in a mate embody these cues. Women judge short men to be undesirable for either a short-term or a long-term mate (Buss & Schmitt, 1993). In contrast, women fnd it very desirable for a potential marriage partner to be tall, physically strong, and athletic. A study of women from Britain and Sri Lanka found strong preferences for male physiques that were muscular and lean (Dixon, Halliwell, East, Wignarajah, & Anderson, 2003). Women also prefer and fnd attractive men with a “V-shaped” torso—broad shoulders relative to hips (Hughes & Gallup, 2003). Another good index of physical formidability is handgrip strength (Gallup & Fink, 2018), which may be why men sometimes show of in mate-attraction tactics by volunteering to open the lids on jars that are especially difcult to open (Buss, 1988a). Women who are especially fearful of crime show even stronger preferences for long-term mates who are physically formidable (Snyder et al., 2011). Moreover, women exposed in an experiment to images of men fghting with each other or images of weapons increased their preferences for masculine-looking male faces—likely a cue to protection (Little, DeBruine, & Jones, 2013). Tall men are consistently seen as more desirable as dates and mates than are short or average men (Courtiol, Ramond, Godelle, & Ferdy, 2010; Ellis, 1992). Two studies of personal ads revealed that, among women who mentioned height, 80 percent wanted a man to be 6 feet or taller (Cameron, Oskamp, & Sparks, 1978). Personals ads placed by taller men received more responses from women than those placed by shorter men (Lynn & Shurgot, 1984). Indeed, a study of the “hits” received by 1,168 personal advertisements in Poland found that a man’s height was one of the four strongest predictors of the number of women who responded to the male ads (the others being education level, age, and resources) (Pawlowski & Koziel, 2002). Tall men are perceived as more dominant, are more likely to date, and are more likely to have attractive partners than shorter men (see Brewer & Riley, 2009, for a review). Women solve the problem of protection from other aggressive men at least in part by preferring a mate who has the size, strength, and physical prowess to protect them. These physical qualities also contribute to solutions to other adaptive problems such as resource acquisitions and genes for good health, since tallness is also linked with status, income, symmetrical features, and good health (Brewer & Riley, 2009). Among the Mehinaku tribe of the Brazilian Amazon, anthropologist Thomas Gregor (1985) noted the importance of men’s wrestling skills as an arena in which these diferences become acute: A heavily muscled, imposingly built man is likely to accumulate many girlfriends, while a small man, deprecatingly referred to as a peristsi, fares badly. The mere fact of height creates a measurable advantage. . . . A powerful wrestler, say the villagers, is frightening . . . he commands fear and respect. To the women, he is “beautiful” (awitsiri), in demand as a paramour [lover] and husband. (p. 35) Preference for Good Health: Symmetry and Masculinity Mating with someone who is unhealthy would have posed a number of adaptive risks for our ancestors. First, an unhealthy mate would have a higher risk of becoming debilitated, thus failing to deliver whatever adaptive benefts might otherwise be provided such as food, protection, health care, and investment in childrearing. Second, an unhealthy mate would be at greater risk of dying prematurely, thereby cutting of the fow of resources and forcing the search for a new mate. Third, an unhealthy mate might transfer communicable diseases. Fourth, an unhealthy mate might infect the children of the union, imperiling their chances of surviving and reproducing. And 113 114 ChALLENGES OF SEx AND MATiNG ffh, if health is partly heritable, a person who chooses an unhealthy mate would risk passing on genes for poor health to children. For all these reasons, women and men both place a premium on the health of a potential mate. In the study of 37 cultures, on a scale ranging from 0 (irrelevant) to +3 (indispensable), women and men both judged “good health” to be highly important. Averaged across the cultures, women gave it a +2.28 and men gave it a +2.31 (Buss et al., 1990). An important physical marker of good health is the degree to which the face and body are symmetrical (Gangestad & Thornhill, 1997; Grammer & Thornhill, 1994; Shackelford & Larsen, 1997; Thornhill & Møeller, 1997). Environmental events and genetic mutations produce deviations from bilateral symmetry, creating lopsided faces and bodies. Some individuals are able to withstand such events and stresses better than others—that is, they show developmental stability. The presence of facial and bodily symmetry is an important health cue, refecting an individual’s ability to withstand environmental and genetic stressors. Therefore, women are hypothesized to have evolved a preference for men who show physical evidence of symmetry. Such symmetry would not only increase the odds of the mate being around to invest and less likely to pass on diseases to her children, it may have genetic benefts as well. By selecting a man with symmetrical features, a woman may be selecting a superior complement of genes to be transmitted to her children. Some evidence supports the hypothesis that symmetry is indeed a health cue and that women especially value this quality in mates (Gangestad & Thornhill, 1997; Thornhill & Møeller, 1997). First, facially symmetric individuals score higher on tests of physiological, psychological, and emotional health (Shackelford & Larsen, 1997). Second, there is positive relationship between facial symmetry and judgments of physical attractiveness in both sexes. Third, women judge facially symmetrical men, compared with their more lopsided counterparts, to be more sexually attractive. Facial symmetry is linked to judgments of health (Jones et al., 2001). Men with more symmetrical faces experienced fewer respiratory illnesses, suggesting better disease resistance (Thornhill & Gangestad, 2006). Some researchers, however, question the quality of the studies and conclude that the evidence on the association between symmetry and health is not yet fully convincing (Rhodes, 2006). Another health cue might stem from masculine features. The average faces of adult men and women difer in several fundamental respects. Men tend to have longer and broader lower jaws, stronger brow ridges, and more pronounced cheekbones, primarily as a consequence of pubertal hormones such as testosterone. Victor Johnston and his colleagues developed a sophisticated experimental tool to vary these features, in the form of a 1,200-frame QuickTime movie (Johnston, Hagel, Franklin, Fink, & Grammer, 2001). The computer program allows a person to search through hundreds of faces that vary in masculinity, femininity, and other features. Participants use a slider control and single-frame buttons to move back and forth through the 1,200-frame movie to locate the frame containing the desired target, such as “most attractive for a long-term mate.” Women overall preferred faces that were more masculine-looking than average. A metaanalysis of 10 studies confrmed that masculinity is attractive in male faces, although the efect size is modest (+.35) (Rhodes, 2006). Women also fnd vocal masculinity to be attractive (Feinberg, DeBruine, Jones, & Little, 2008). Why would women fnd masculine-looking males attractive? Johnston argues that masculine features are signals of good health. High levels of testosterone compromise the human immune system. According to Johnston’s argument, only males who are quite healthy can “aford” to produce high levels of testosterone during their development. Less healthy males must suppress testosterone production, lest they compromise their already weaker immune systems. As a result, healthy males end up producing more testosterone and developing more rugged masculine-looking faces. If Johnston’s argument is 4 WOMEN’S LONG-TERM MATiNG STRATEGiES 115 Most women fnd men with symmetrical faces, as exemplifed by the actor Denzel Washington (lef), to be more attractive than men with asymmetrical faces, as illustrated by the musician and actor Lyle Lovett (right). Symmetry is hypothesized to be a health cue that signals a relative absence of parasites, genetic resistance to parasites, or a relative lack of environmental insults during development. © AF archive/Alamy correct, women’s preference for masculine faces is a preference for a healthy male. Support for this hypothesis comes from the fnding that women living in low-health nations have especially strong preferences for facial masculinity (Pisanski & Feinberg, 2013). Moreover, women who are especially sensitive to becoming disgusted by cues to pathogen-causing diseases also show especially strong preferences for masculine male faces (DeBruine, Jones, Tybur, Lieberman, & Giskevicius, 2010). Johnston went through the 1,200-frame QuickTime movie a second time and asked the women to pick out the face they viewed as the “healthiest.” The faces women chose were indistinguishable from their judgments of “the most attractive face,” supporting the theory that masculine appearance might be valued by women because it signals health. Another study found that men with more masculine faces had fewer respiratory diseases, suggesting that it might be a signal of disease resistance (Thornhill & Gangestad, 2006). Other researchers present evidence that women’s attraction to masculine features refects dominance in same-sex competition rather than health (Boothroyd, Jones, Burt, & Perrett, 2007; see also Puts, Welling, Burris, & Dawood, 2012; Scott, Clark, Boothroyd, & Penton-Voak, 2013). Importantly, masculine features are also cues to physical formidability, which would help a woman solve the adaptive problem of protection. ChALLENGES OF SEx AND MATiNG 116 Love and Commitment Women have long faced the adaptive problem of choosing men who not only have the necessary resources but also show a willingness to commit those resources to them and their children. Although resources can ofen be directly observed, commitment cannot. Instead, gauging commitment requires looking for cues that signal future channeling of resources. Love may be one of the key cues to commitment (Buss, 2018b). According to conventional wisdom in the social sciences, “love” is a relatively recent invention, introduced a few hundred years ago by romantic European poets (Jankowiak, 1995). Research suggests that this conventional wisdom is radically wrong. There is evidence that loving thoughts, emotions, and actions are experienced by people in cultures worldwide— from the Zulu in the southern tip of Africa to the Inuit in the cold northern ice caps of Alaska. In a survey of 168 diverse cultures around the world, anthropologists William Jankowiak and Edward Fischer examined four sources of evidence for the presence of love: the singing of love songs, elopement by lovers against the wishes of parents, cultural informants reporting personal anguish and longing for a loved one, and folklore depicting romantic entanglements. They found evidence for romantic love in 88.5 percent of the cultures (Jankowiak, 1995; Jankowiak & Fischer, 1992). Clearly love is not a phenomenon limited to the United States or to Western cultures. To identify precisely what love is and how it is linked to commitment, several studies examined acts of love (Buss, 1988a, 2018b; Wade, Auer, & Roth, 2009). Acts of commitment top women’s and men’s list as most central to love. These acts include giving up romantic relations with others, talking of commitment and marriage, and expressing a desire to have children with this person. When performed by a man, these acts of love signal the intention to commit resources to one woman and her future children. Reports of experiencing love powerfully predict feelings of subjective commitment—far more than reports of sexual desire (Gonzaga, Haselton, Smurda, Davies, & Poore, 2008). The hypothesis that the commitment of paternal care to children is one of the functions of love attains support from a comparative and phylogenetic analysis of diferent species that looked at the links between adult attachment and paternal care (Fraley et al., 2005). Species that exhibited adult attachment were more likely to be characterized by male parental investment in ofspring than species that did not. Thus, one function of the female preference for love in a mate is to ensure the commitment of his parental resources to the children they produce together. One component of commitment is fdelity, exemplifed by the act of remaining faithful to a partner when not physically together. Fidelity signals the exclusive commitment of sexual resources to a single partner. Another aspect of commitment is the channeling of resources to the loved one. Emotional support is another facet of commitment, revealed by being available in times of trouble and listening to the partner’s problems. Commitment entails a channeling of time, energy, and efort to the partner’s needs at the expense of fulflling one’s own personal goals. Acts of reproduction also represent a direct commitment to one’s partner’s reproduction. All these acts, which are viewed as central to love, signal the commitment of sexual, economic, emotional, and genetic resources to one person. Because love is a worldwide phenomenon, and because the primary function of acts of love is to signal commitment, women are predicted to place a premium on love in the process of choosing a long-term mate. The international study on choosing a mate confrmed the importance of love across cultures. Among 18 possible characteristics, mutual attraction or love proved to be the most highly valued in a potential mate by both sexes, rated 2.87 by women and 2.81 by men (Buss et al., 1990). Nearly all women and men, from the Zulu of South Africa to urban Brazilians, gave love the top rating, indicating that it is an indispensable part of long-term mating. Another study of love in 48 nations found high levels of love in all of them (Schmitt et al., 2009). 4 WOMEN’S LONG-TERM MATiNG STRATEGiES 117 Researchers have made progress in identifying the underlying brain mechanisms involved in love (Bartels & Zeki, 2004; Fisher, Aron, & Brown, 2005). Using functional magnetic resonance imaging (fMRI) technology, researchers scanned the brains of individuals who were intensely in love while they thought about their loved one. The specifc areas of the brain that “lit up” (showed an increased blood fow, indicating changes in neural activity) centered on the caudate nucleus and the ventral tegmental areas. These areas contain cells that produce dopamine, which stimulates the reward centers of the brain, analogous to experiencing a “rush” of cocaine (Fisher, 2006). Thus, researchers are beginning to make progress in identifying the underlying brain circuits involved in the psychological state of love. Preference for Willingness to Invest in Children Another adaptive problem that women face when selecting a long-term mate is gauging men’s willingness to invest in children. This adaptive problem is important for two reasons: (1) Men sometimes seek sexual variety and so may channel their eforts toward other women (mating efort) rather than toward children (parental efort; see Chapter 6); and (2) men evaluate the likelihood that they are the actual genetic father of a child and tend to withhold investment from the child when they know or suspect that the child is not their own (La Cerra, 1994). To test the hypothesis that women have an evolved preference for men who are willing to invest in children, psychologist Peggy La Cerra constructed slide images of men in several diferent conditions: (1) a man standing alone; (2) a man interacting with an 18-month-old child, including smiling, making eye contact, and reaching for the child; (3) a man ignoring the child, who was crying; (4) a man and the child simply facing forward (neutral condition); and (5) a man vacuuming a living room rug. The same models were depicted in all conditions. After viewing these slide images, 240 women rated each image on how attractive they found the man in each slide as a date, as a sexual partner, as a marriage partner, as a friend, and as a neighbor. The rating scale ranged from −5 (very unattractive) to +5 (very attractive). First, women found the man interacting with the child positively to be more attractive as a marriage partner (average attractiveness rating, 2.75) than the same man either standing alone (2.0) or standing neutrally next to the child (2.0). Second, women found the man La Cerra (1994) found that women fnd the man interacting positively with the baby considerably more attractive, suggesting a mate preference for men who display a willingness to invest in children. Comparable photographs of women, shown either ignoring or interacting positively with a baby, produced no efect on men’s judgments of women’s attractiveness. iStock © jarenwicklund ChALLENGES OF SEx AND MATiNG 118 who ignored the child in distress to be low in attractiveness as a marriage partner (1.25), indeed the lowest of all. Third, the efect of interacting positively with the child proved not to be a result of the man showing domestic proclivities in general. Women found the man vacuuming, for example, to be less attractive (1.3) than the man simply standing alone doing nothing (2.0). This study suggests that women prefer men who show a willingness to invest in children as marriage partners. Is this preference unique to women? To address this issue, la Cerra conducted another study, this time using women as models and men as raters. Women were posed in conditions parallel to those of the male models in the frst study. The results for men were strikingly diferent from those for women. Men found the woman standing alone to be just as attractive (average attractiveness rating, 2.70) as the woman interacting positively with the child (2.70). In fact, the varying contexts made little diference to men in their judgments of how attractive the woman was as a marriage partner. In short, women appear to have a specifc preference for and attraction to men who show a willingness to invest i