Mating Strategies

Women's Long Term Mating Strategies:

Nowhere do people have an equal desire for all members of the opposite sex. Everywhere, some potential mates are preferred, while others are ignored or even actively avoided. If you imagine what it would have been like living as our ancestors did; struggling to keep warm (if they were in a temperate climate), hunting game, gathering nuts, berries and herbs, avoiding dangerous animals and hostile humans, it is clear that if one had chosen a mate who was lazy, lacked hunting or gathering skills, who had affairs, who abused us or who failed to share resources would have put our very survival, not to mention reproduction at risk. Thus, powerful survival and reproductive benefits were reaped by those ancestors who chose mates wisely and as a result, specific desires for specific kinds of mate traits have evolved and are still present in modern humans today.

One of the problems that women have had to face over evolutionary history is selecting a mate who would be willing to commit to a long-term relationship because otherwise she would have found herself raising children alone and without benefit of the resources, aid and protection that a mate might have offered. A women who preferred to mate with a reliable man who was willing to commit to her presumably would have had children who survived and thrived and multiplied. Over thousands of generations, a preference for men who showed signs of being willing and able to commit evolved in women.

In real life men vary in their generosity, strength, athleticism, ambition, industriousness, kindness, empathy, emotional stability, intelligence, social skills, sense of humor, kin network and position in the status hierarchy. Men also vary in the costs they carry into the relationship (e.g. bad debts or bad tempers) obviously carry costs with them.

From among the thousands of ways in which men differ, selection over hundreds of thousands of years has focused women's preferences on the most adaptively valuable characteristics. Women lacking specific adaptively-relevant preferences are not our ancestors, because they were out-reproduced by choosier women.

It is also true that in real life, people change over time. Thus, what a woman may actually have to do is judge a potential mate not on current position, but what she thinks he is capable of in the future. For example, a medical school student may not have many resources now and may be deeply in debt, but in 10 years be very comfortable in terms of resources to share. Thus, evolution has favored women who prefer men possessing those attributes that confer benefits and who dislike men possessing those attributes that impose costs. Each of her preferences tracks one critical component. In addition, when weighing up potential benefits and costs, women also have to be aware that men may be deceiving them, such as pretending greater status, or having more resources or more being willing to give commitment than they actually are (these are all areas in which men historically deceive women).

While choosing a mate is a complex task, we should not expect to find simple answers to what women want, but since probably no other research questions has received as much attention in evolutionary psychology as mate choice in human females, we at least have some possible answers to this question.

Adaptive Problems in Long-Term Mating and Hypothesized Solutions:

Adaptive Problems Evolved Mate Preference
1. Selecting a mate who is able to invest good financial prospects, social status, older age, ambitious/industrious, size, strength, athleticism
2. Selecting a mate who is willing to invest dependability and stability, love and commitment cues, positive interactions with children
3. Selecting a mate who is able to physically protect self and childrensize (height), strength, bravery, athletic ability, healthy
4. Selecting a mate who will show good parenting skillsdependability, emotional stability, kindness, positive interactions with children
5. Selecting a mate who is compatiblesimilar values, similar ages, similar personalities


Among humans, the evolution of women's preferences for a permanent mate with resources would have required 3 preconditions:

  1. First, resources would have to be accruable, defensible, and controllable by men during human evolutionary history.

  2. Second, men would have to differ from each other in their holdings and their willingness to invest those holdings in a woman and her children, because if all men possessed the same resources and showed an equal willingness to allocate them, there would be no need for women to develop such a preference for them.

  3. Third, the advantages of being with one man would have to outweigh the advantages of being with several men.

These conditions are easily met in humans. Territory and tools, to name just two resources, are acquired, defended, monopolized and controlled by men worldwide. Men also vary tremendously in the quantity of resources they command and in how willing they are to invest their time and resources in long-term mate-ships, with some men preferring to mate with many women and invest little in any of them, while others channel all their resources into one woman and her children.

Over the course of human evolution, women could often gather many more resources for their children through staying with a single partner or spouse than through several temporary sex partners. Men invest in their wives and children to an extent unprecedented among primates. In all other primates, females must rely solely on their own efforts to acquire food because males never share those resources with their mates. Men, in contrast, provide food, shelter, defend territory, and protect their children. They also teach them things such as sports, hunting, fighting, hierarchy negotiation, friendship and social influence. They transfer status and aid offspring in forming reciprocal alliances later in life, These benefits are unlikely to be secured by a woman from a temporary sex partner. Not all potential partners/spouses/husbands can confer all of these benefits, but over thousands of generations, when some men were able to provide some of them, women benefited by choosing those men as mates.

So, clearly women should have evolved preferences for men with resources, but women also needed to evolve a way to understand the cues that signal that a man has resources. These cues might be indirect, such as personality characteristics that signal a man's upward mobility; physical such as athletic ability or health; they might include reputation, such as how much esteem others hold the man in; but the possession of economic resources clearly is the best signal that a man has resources to share.

Current Preferences for Good Financial Prospects:

Currently held mate preferences provide a window for viewing our mating past. Evidence from dozens of studies document that modern American women value economic resources in mates substantially more than men do. In one study (1939) men and women rated 18 characteristics for their relative desirability in a marriage partner, ranging from irrelevant to indispensable. Women rated good financial prospects as more desirable than men, and this finding has been replicated over and over again in many subsequent studies. For example, in 1989, Buss replicated this study and found that women still valued good financial prospects in a mate roughly twice as much as did men.

The value that women place on economic resources has been revealed in a wide variety of contexts. Kenrick and his colleagues devised a useful method for revealing how much people value different attributes in a marriage partner by having men and women indicate the "minimum percentiles" of each characteristic they would find acceptable (1990). The percentile concept was explained with such examples as the following "A person at the 50th percentile would be above 50% of the other people on earning capacity and below 49% of the people on this dimension". American college women indicate that their minimum acceptable percentile for a husband on earning capacity is the 70th percentile, or above 70% of all other men, whereas men's minimum acceptable percentile for a wife's earning capacity is only the 40th percentile. Women also show higher standards for economic capacity in a dating partner, in a sexual relationship and in a steady dating context.

Personal ads in newspapers and magazines also confirm that women actually on the marriage market desire strong financial resources. A study of 1,111 personal ads found that female advertisers seek financial resources roughly 11 times as often as male advertisers do (Wiederman, 1993).

These female preferences are not restricted to America or to Western societies. A large cross-cultural study was conducted of 37 cultures on six continents and 5 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 or cultures that practice polygyny such as Nigeria and Zambia. Other participants came from nations or cultures that tend to be monogamous 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 is strongly discouraged, such as Bulgaria and Greece. The study sampled a total of 10,047 people in 37 cultures.

Male and female participants in the study rated the importance of 18 characteristics in a potential mate or marriage partner on a scale from unimportant (0) to indispensable (3). Women across all continents, political systems, racial groups, religious groups and all systems of mating placed more value than men on good financial prospects. Overall, women valued financial resources roughly twice as much as men. There are cultural variations; women in Nigeria, Zambia, India, Indonesia, Iran, Japan, Taiwan, Colombia and Venezuela valued good financial prospects higher than women from South Africa, the Netherlands and Finland. In Japan, women valued good financial prospects roughly 150% more than men, whereas women from the Netherlands value it only 36% more than males, less than women from any other country. However, the sex differences occurred in every country and culture sampled.

These findings provide the first extensive cross-cultural evidence supporting the evolutionary basis for the psychology of human mating. Because ancestral women faced the tremendous burdens of internal fertilization, a 9 month gestation, and lactation, they would have benefited tremendously by selecting mates who possessed resources. These cross-cultural data support the hypothesis that current women are the descendants of a long line of women who had these mate preferences-preferences that helped their ancestors solve the adaptive problems of survival and reproduction.

Preference for High Social Status:

Traditional hunter-gatherer societies, which are our closest guide to what ancestral conditions were probably like, suggest that ancestral men had clearly defined status hierarchies, with resources flowing freely to those at the top and trickling slowly down to those at the bottom (Betzig, 1986; Brown and Chia-yun, n.d.). Women appear to desire men who command a high position in society 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 males worldwide, access to more and better quality mates typically accompanies families of higher social status. In one study of 186 societies ranging form the Mbuti Pygmies of Africa to the Aleut Eskimos, high-status men invariably had greater wealth and more wives and provided better nourishment for their children (Betzig, 1986).

Women in the U.S. express a preference for mates who have high social status or a high-status profession, qualities that are viewed as only slightly less important than good financial prospects. Using a rating scale from irrelevant or unimportant to indispensable, American women rated social status as between important and indispensable, whereas men rated it as merely desirable but not very important. In another study of college women at U of Michigan, Buss found that on a scale of minus 3 (extremely undesirable) to +3 (extremely desirable), women rated success in a profession (+2.6) and the possession of a promising career (+2.7) as desirable in a spouse. They also prefer men with educations, rating men without a good education as extremely undesirable (-2.39). In the previous cross-cultural study, women also rated social status in prospective husbands as more desirable than men did for prospective spouses.

Hierarchies are universal features among human groups and resources tend to accumulate to those who rise in the hierarchy. Women historically appear to have solved the adaptive problem of acquiring resources in part by preferring men who are high in status. Modern women are the descendants of these successful ancestors and so have inherited their mate preferences.

Preference for Older Men:

The age of a man also provides an important clue to his access to resources. Human adolescents and young men rarely command the respect, status, or position of more mature men. In all 37 countries included in the international study on mate selection, women preferred older men-averaged over all cultures, they preferred men who were about 3.5 years older. The worldwide average age difference between actual brides and grooms is about 3 years, suggesting that women's marriage decisions often match their mating preferences.

This attraction to older men is probably based on the fact that older men tend to have better access to resources. In contemporary Western culture, income increases with age. Older age, resources and status are coupled across all cultures and in traditional cultures part of this linkage may be related to physical strength and hunting prowess. Physical strength increases in men as they get older and peaks in their late twenties and early thirties. Anthropologists believe that hunting skill peaks in the mid-thirties, at which point any slight decline in physical ability is more than compensated by for increased knowledge, patience, skill and wisdom. Women's preference for older men may stem from our hunter-gatherer ancestors, for whom resources derived from hunting were critical for survival.

When 20 year old women in the international study were asked which age man they would prefer to marry, they preferred men only a few years older, not men in their 40s and 50s, who would be assumed to have amassed many more resources. It is assumed that they do not prefer much older men because of the risk of them dying and the consequent inability to provide for children.

All of these preferences add up to one thing, the ability of a man to acquire and control resources that women can use for themselves and their children. The possession of resources, however, is not enough, women also need men who are likely to lead to the sustained acquisition of resources over time. A man's ambition is one of those traits.

Preference for Ambition and Industriousness:

Liisa Kyl-Heku sought to identify the tactics that people use to elevate their position in hierarchies at work and in social settings (Kyl-Heku and Buss, 1996). She asked 84 people to think about people they knew well and to write down the acts they had seen these people use to get ahead in status or dominance hierarchies. Statistically, she then discovered 26 tactics including deception, social networking, sexual favors, education and industriousness. The industriousness tactic included actions such as putting in extra time and effort at work, managing time efficiently, prioritizing goals and working hard to impress others. She then asked 212 people in their mid-to-late-twenties to indicate which tactics they had used. She separately asked their spouses to indicate which tactics their partners had used. Next, she correlated this information to their past income and promotions and their anticipated incomes and promotions to see which tactics for getting ahead were the most successful.

Among all the tactics, sheer hard work proved to be the best predictors of past and anticipated income and promotions. Those who said they worked hard and whose spouses agreed that they worked hard achieved higher levels of education, higher annual salaries, and anticipated greater salaries and promotions than those who failed to work hard. Industrious and ambitious men secure a higher occupational status than lazy, unmotivated men.

American women seem to be aware of this connection, because they indicate a desire for men who show characteristics linked with getting ahead. In the 1950s, for example 5,000 undergraduates were asked to list characteristics that they sought in a potential mate. Women, far more than men, desired mates who enjoy their work, show career orientation, demonstrate industry and display ambition (Langhorne and Secord, 1955). In Buss's international study of 37 countries, the American women unanimously rated ambition and industriousness as important or indispensable. Men, on the other hand, seem to view ambition as neither desirable nor undesirable. Women have also been shown to be likely to discontinue a long-term relationship with a man if he loses his job (Betzig, 1989). Women's preference for industriousness is not limited to America. In the overwhelming majority of cultures in the 37 country study, women valued ambition and industry more than men do, typically rating it as in between important and indispensable.

These studies indicated that women have evolved a preference for men possessing sign of the ability to acquire resources and a disdain for men lacking the ambition that often leads to resources.

Preference for Dependability and Stability:

Among the characteristics rated in the worldwide study on mate selection, the second and third most valued characteristics, after love, are a dependable character and emotional stability or maturity. Men and women seem to rate dependability as equally important, but in the case of emotional stability or maturity slightly more important than do men.

Clearly dependability and stability are related to resource acquisition. The more stable a man is, the more likely he will be able to provide consistently; in addition, he will not inflict great emotional costs on his partner. Studies indicate that emotionally unstable men (as identified by self, spouse and therapist) are very costly to women; they tend to be self-centered, monopolize shared resources, tend to be possessive, show higher than average jealousy, are dependent, tend to be abusive both verbally and physically, display inconsiderate behavior and are more moody. They also have more affairs than usual. Clearly, dependability and emotional stability indicate that a man will not drain his partner's resources.

Preference for athletic ability:

The importance of physical characteristics in the female choice of a mate is notable throughout the animal world. 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 our ancestor's lives. Studies of many nonhuman primate groups reveal that male physical and sexual domination of females has been a recurrent part of our primate heritage (but remember Bonobos). In baboons, for example, in which males are dominant to females, females will form 'enduring friendships' with males who offer physical protection for themselves and their infants against other males. In return, the females mate selectively with those 'friends'.

It appears that in humans, also, one benefit of long term mating to a women is the physical protection a man can offer. A man's size, strength, physical prowess and athletic ability are cues that signal solutions to the problem of protection. In a study of temporary and permanent matings, American women rated the desirability of a series of physical traits. Women judged short men to be undesirable for either a short-term or long-term mate, but found tall, physically strong and athletic males to be most desirable. Men do not rate these qualities as highly desirable. Barbara Smuts believes that during human evolutionary history, physical protection was one of the most important things a man could offer a woman. Aggressive men wishing to dominate women physically and to circumvent women's sexual choices may have exerted an important selection pressure on women in ancestral times. Given the fairly high incidence of sexual coercion and rape found in many cultures, a mate's protection may well remain a selectively relevant force in modern environments. One psychologist sums it up as "traits of male body structure such as height, shoulder width and upper-body musculature are sexually attractive to women and also intimidating to other men" (Barber, 1995).

Preference for Good Health:

Mating with someone unhealthy would obviously pose a number of adaptive risks for our ancestors.
  1. First, an unhealthy mate would have a higher risk of becoming debilitated, thus failing to deliver whatever benefits he or she might otherwise have provided, such as a food, protection, health care, investment in child rearing.

  2. Second, an unhealthy mate would have a higher risk of dying, cutting off the flow of resources.

  3. Third, an unhealthy mate might transfer communicable diseases or viruses to the other mate, impairing his or her survival and reproduction.

  4. Fourth, an unhealthy mate might infect the children imperiling their chances of surviving and reproducing.

  5. Finally, an unhealthy mate might pass on poor genes to his or her children, resulting in poor health in the children.

Clearly, both men and women should put a premium on choosing a healthy mate. Across cultures, both men and women rate health to be highly important.

You remember earlier in the course when we discussed sexual selection and reasons for why it might exist. Thornhill, et al. have discovered an important physical marker of good health to be symmetry. Their reasoning is that various environmental events and genetic stressors produce deviations from bilateral symmetry during development, creating lopsided faces and bodies. Some individuals are better able to withstand such events and stressors than others-they show developmental stability. Thus, the presence of facial and body symmetry is an important health cue, reflecting an individual's ability to withstand environmental and genetic stressors. Women are suggested to have evolved a preference for men who show symmetry, which might indicate the odds of the mate being around to invest for a long time and less likely to pass on diseases to herself or her children. She may also, by selecting a symmetrical male, be selecting to pass on those genes to her children.

A large body of evidence supports the idea that symmetry is a health cue and women value this quality. Facially symmetric individuals score higher on tests of physical, psychological and emotional health. Second, there is a positive relationship between facial symmetry and judgments of physical attractiveness in both sexes. Third, facially symmetrical men compared with more lopsided men, are judged to be more sexually attractive by women, have more sexual partners during their lifetimes and have more extra-pair copulations and begin sexual intercourse earlier.

Preference for Love:

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. This may be more problematic than it first seems. Although resources can often be directly observed, commitment cannot. Instead, gauging commitment requires looking for cues that signal the likelihood of future fidelity in the channeling of resources. Love may be one of those cues to commitment.

According to conventional wisdom in the social sciences, 'love' is a relatively recent invention, introduced a few hundred years ago by romantic Europeans. According to this view, love is a local product of Western culture and will not be found across the globe in societies far removed from European influence.
Recent 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. In a survey of 168 diverse cultures around the world, anthropologists have 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 a folklore depicting romantic entanglements. Using the presence of these criteria, they found evidence for romantic love in 88% of the cultures. In another study, sociologists interviewed 1,667 men and women in Russia, Japan and the U.S., they found that 61% of Russian men, and 73% of Russian women were in love at that time. Comparable figures for Japanese were 41% of men and 63% of women; and in Americans 53% of men and 63% of women. Clearly, love is not limited to Western culture.

To identify what love is and how it is linked to commitment, one study examined acts of love (Buss, 1988). First, 50 women and 50 men (college aged) were asked to think of people they knew who were currently in love and to describe actions performed by those people that would reflect or exemplify their love. A different group of college men and women then evaluated each of the 115 acts named for how typical it was of love. Acts of commitment top women's and men's lists, being viewed as most central to love. Such acts include giving up romantic relations with others, talking of 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.

Direct studies of preferences in mates confirm the importance of love. In one study of college students, out of 100 possible characteristics that could describe a potential mate, the most strongly preferred in a husband was the quality of being loving. The international study by Buss also confirmed the importance of love, since mutual attraction or love proved to be the most highly valued characteristic in a mate by both men and women.

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: OL>
  • Men sometimes seek sexual variety and so may channel their efforts toward other women (mating effort) rather than toward children (parental effort).MBR.
  • Men evaluate the likelihood that they are the actual genetic father of a child and tend to withhold investment from children they know or suspect are not theirs.

    These two factors imply that men will differ widely in how willing they are to invest in a particular child; this variability is essential for the evolution of women's preferences for men who show signs of willingness to invest in children.

    To test the hypothesis that women have an evolved preference for men who are willing to invest in children, La Cerra constructed slide images of men in several different 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 a child simply facing forward.

    5. A man vacuuming a living room rug.

    The same models were used in all conditions.

    After viewing the images, 240 undergraduate women rated each image on how attractive they found the man as a date, sexual partner, marriage partner, friend and neighbor. The rating scale ranged from minus 5 (very unattractive) to +5 (very attractive).

    1. First, women found the man interacting with the child positively to be more attractive as a marriage partner than the same man either standing alone or standing neutrally next to the child.

    2. Second, women found the man who ignored the child in distress to be low in attractiveness as a marriage partner (the lowest score of all).

    3. Third, the effect of interacting positively with the child proved not to be the result of the man showing domestic proclivities in general. Women found the man vacuuming to be less attractive than the man simply standing alone doing nothing.

    From this study, La Cerra concluded that "women's ratings of the attractiveness of men as a potential mate are increased by cues of their affection toward a child and decreased by cues of their indifference toward a child in distress (1994). Men shown comparable photos of women either ignoring a child or interacting positively with the child produced no effects on men's judgments of the attractiveness of the women.

    From an evolutionary perspective, preferences are not expected to operate blindly, oblivious to context. Just as human desires for particular foods will depend on context (if you are hungry or not), women's preferences in a mate should also depend on context. Two of those possible context that have been considered are how many resources a woman already has of her own and whether she is looking for a long-term or short-term partner.

    Women's resources:

    There is a group called the Bakweri, from Cameroon in West Africa, in which women hold greater personal and economic power than do the males (1960 study). Women work for their economic gain on plantations, but they also trade sexual favors for money. There are roughly 236 men for every hundred women since there is a constant influx of men from surrounding areas to work on the plantations. Because of this extreme imbalance in the sexes, women can be very choosy about who they mate with. Bakweri women persist in choosing males who have the most resources, even though the women themselves have plenty of money and will quickly divorce men who do not share or if the women can find a man with more money/resources. Clearly, the mate preference for resources still persists even in the face of the woman controlling resources of her own.

    A study of American women confirms this finding. They contrasted financially successful women (most making around $100,000.00 a year with women who earned lower salaries (less than $50.000.00) a year. The study showed that successful women place an even greater value than less successful women on mates who have professional degrees, high social status and greater intelligence and who are tall, independent and self-confident. Women's personal income was positively correlated with the income they wanted their spouse to make, and the more they made, the more they expected their spouse to make.

    Finally, in a study of college women in the US, they found that college women who expect to earn the most after college put the most weight on the promising financial prospects of a possible husband.

    Clearly, even when they can support themselves and children, women still express the mate preference for a male with resources or potential resources.

    We will explore the differences between short-term mating preferences and long-term preferences for women in a separate topic, let me just say that for long-term mating, women prefer character traits such as loyalty, dependability and kindness more than attractiveness (which is what they prefer for short-term mating).

    Men's Long Term Mating Strategies:

    For selection to have produced psychological mechanisms in men that incline them to seek marriage and commit years and decades of investment to a woman, it is reasonable to assume that there were adaptive advantages to long-term mating, at least under some circumstances.

    Why men might benefit from commitment and marriage:

    1. One solution to the puzzle of why men would seek marriage comes from the ground rules set by women. Because it is clear that many ancestral women required reliable signs of male commitment before consenting to sex, men who failed to commit would have suffered selectively on the mating market. For that matter, men who failed to show interest in commitment might have failed to attract any women at all. Women's requirements for consenting to sex could have made it costly for men to pursue a short-term mating strategy exclusively. In the economics of reproductive effort, the costs of not pursuing a permanent mate may have been prohibitively high for most men. Thus, one benefit is the increased odds of simply attracting a mate at all.

    2. Another benefit of marriage is an increase in the quality of a woman a man would be able to attract. Men who are willing to promise long-term resources, protection and investment in children are appealing to women and so men who are willing to commit to the long term have a wider range of women from which to choose. Such men attract desirable women because men of high status typically impose more stringent standards for a spouse than most women are able to meet.

    3. A third potential benefit would be an increase in the odds that the man is the father of the children a woman bears. Through marriage, a man gains repeated sexual access-in many cases exclusive sexual access. Without this repeated or exclusive access, his certainty of paternity would be jeopardized. Thus, men who marry gain the reproductive benefit of an increase in paternity certainty.

    4. Fourth, marriage likely causes an increase in the survival of a man's children. In human ancestral environments, it is likely that infants and young children more frequently died without the prolonged investment from two parents or related kin. Even today among the Ache Indians of Paraguay, when a man dies the other villagers sometimes make a mutual decision to kill certain of his children, even when they have a living mother. This stems from an Ache custom in which a man's living children are sometimes buried along with the dead father. The sacrificed children, are usually young girls under the age of 5, but they can be boys as well and as old as 12. Often a single child is chosen and it is not uncommon that it is one that is ill or has a birth defect.

      This practice is justified by the Ache on the grounds that burying a man's children would appease his angry spirit and so the spirit would not attempt to take another living adult with him on the journey to death. The Ache also insist that many of the child victims would not be cared for adequately, and a child with no father would be ' constantly begging for food" and would be a resource drain on the whole group. Overall, Ache children whose fathers had died, suffered a death rate 10% higher than children with living fathers. While this is only one group, and we can't make generalizations from one group, it is possible that in ancestral times, children without one parent were more likely not to survive.

    5. Finally, the last benefit that might accrue to a man willing to commit to marriage is that his children may have increased reproductive success due to his teaching, knowledge and the political alliances that he has.

    How to assess a woman's fertility or reproductive value:

    To be reproductively successful, ancestral men had to marry women with the capacity to bear children, and a woman with the capacity to bear many children would obviously be of more value than one who can bear only a few or none at all. Men cannot observe a woman's reproductive value directly, and so selection should have given men preferences for qualities that are correlated with reproductive value.

    When we compare humans with one of our closest great ape relatives, the chimpanzees, we see in humans a discontinuity in the female advertisement of reproductive status. When the female chimpanzee is capable of conceiving, she goes into a phase called estrus, the time during which she ovulates and is also sexually receptive. This receptivity is advertised by bright red swollen genitals and scents that are highly attractive to a male chimpanzee. Almost all sexual activity in the chimpanzee takes place during this time of estrus when the female is likely to conceive.

    Humans, of course, are markedly different. Ovulation in a human woman is concealed or hidden and there is no genital swelling to mark a time of receptivity. Second, of course, sexual activity occurs at any time of the menstrual cycle and is not confined to one particular time of receptivity and is not confined to the time during which she is most likely to become pregnant.

    The transition from advertised estrus to concealed ovulation posed an adaptive problem for our male ancestors. For chimpanzee males, the problem of detecting a female's reproductive status is easy, all he has to do is look. What can human males use, however? They have no guide, so concealed ovulation shifted the problem from one of detecting when a woman was ovulating to one of determining which women were likely to be capable of conceiving children.

    Reproductive value refers to the number of children a person of a given age and sex is likely to have in the future. A woman who is 15 years old, for example, has a higher reproductive value than one who is 30 because, on average, the younger woman is likely to bear more children in the future than the older woman. Individuals, of course, defy these averages-the 15 year old may decide never to have children while the 30 year old may have 6 more. The key concept here is that that reproductive value is the average expected future reproduction of a person of a given age and sex.

    Reproductive value is different from fertility, which is defined as actual reproductive performance, measured by the number of viable offspring produced. In human populations, women in their mid-20s tend to produce the most viable offspring and fertility in humans is at its peak in the mid-20s.

    The difference between fertility and reproductive value can be illustrated by contrasting two females, one 15 and one 25. The younger female has a higher RV because her future reproduction is expected to be greater than the older woman; but the woman in her mid-20s has higher fertility because women in their mid-20s produce more children than do teenagers.

    Men should have developed some kind of evolved mechanism to be sensitive to observable cues that are correlated with underlying fertility, and two potential cues are youth and health.

    Men's Mate Preferences:

    In some ways, men's mate preferences are similar to those of women. Like women, men express a desire for women who are intelligent, kind, understanding and healthy. Also, like women, men look for partners who share their values and are similar to them in attitudes, personality and religious beliefs. But, because ancestral men confronted a different set of adaptive mating problems than did ancestral woman, they should have a slightly different set of mate preferences.

    Preferences for Youth: Youth is a critical cue because a woman's RV declines as she ages past the age of 20. By the age of 40, a woman's reproductive value is low and by 50 it is almost non-existent. The window of opportunity for reproduction is thus compressed into only a fraction of her entire lifespan.

    Men's preferences capitalize on this. Within the US, men consistently express a desire for mates who are younger than they are. Among college students surveyed from 1939-1988, the preferred age differences was around 2.5 years.

    Men's preferences for younger women are not limited to the US. When the Yanomamo Indians men of the Amazon were asked by an anthropologist which women were most sexually attractive, they reply that women who are post-pubescent but have not yet borne their first child are most attractive. Comparable information from other hunter-gatherer societies show similar kinds of preferences.

    In every one of the 37 countries surveyed by Buss, men preferred younger wives, and the average across countries is about 2.5 years.

    A comparison of personal ads in the US also indicates that as men get older, they prefer as mates women who are increasingly younger; with men in their thirties preferring women who are roughly 5 years younger; and men in their fifties preferring women who are 10-20 years younger.

    According to evolutionary psychologists, what men desire is not youth per se, but rather features of women that are associated with reproductive value or fertility. This perspective leads to a counterintuitive prediction that when it comes to age preferences of adolescent males, they should prefer women who are slightly older than they are because slightly older women have higher fertility than women their own age or younger.

    One study surveyed 103 teenage males and 106 females between the ages of 12-19. Teenage males indicated that they were willing to date younger females, but they were more interested in females who were several years older than themselves. Buss notes that the older women they preferred were completely uninterested in dating these younger men.

    Physical Beauty:

    Our standards for female beauty also embody cues to women's reproductive value. Conventional wisdom dictates that beauty is in the eyes of the beholder, but those eyes and the minds behind the eyes have been shaped by millions of years of human evolution. Beauty is in the adaptations of the beholder.

    Our ancestors had access to two types of observable evidence of a woman's reproductive value: 1) features of physical appearance such as full lips, clear skin, smooth skin, clear eyes, lustrous hair, good muscle tone and body fat distribution and 2) features of behavior, such as bouncy youthful gait, and animated facial expression and a high energy level. These physical cues to youth and health, and thus fertility and RV seem to be some of the key ingredients of male standards of female beauty. Because physical and behavioral cues can provide the most powerful observable evidence of a woman's reproductive value, ancestral men evolved a preference for women who displayed these cues.

    Many studies have shown that universally, clear, smooth skin, shiny hair and full lips and signs of health such as the absence of sores, lesions, parasites, skin eruptions are considered attractive.

    Beauty standards emerge early:

    Traditionally, it has been assumed that standards of beauty are learned and that they do not emerge clearly until 3 or 4 years of age or even older. Langlois, however, had adults evaluate color slides of White and Black females for their attractiveness. Then, she had infants of 2-3 months and 6-8 months shown pairs of faces that had been judged to differ in attractiveness (one more attractive, one less attractive. Infants of both ages gazed at the attractive faces (as judged by the adult) longer than the unattractive face. In a second study, she found that 12 month olds spent more time playing with and showed more pleasure and less distress when exposed to adults wearing attractive masks than those wearing unattractive masks. They also found that 12 month olds spent more time playing with attractive dolls than with unattractive dolls. It seems that standards of beauty are not learned through gradual cultural exposure, but are innate.

    Beauty is consistent across cultures:

    Psychologists have done studies in which they asked people of different races to judge facial attractiveness in Asian, Hispanic, Black and White women from photographs, and they have found enormous consensus about who is and who is not attractive, with correlations ranging from +.91 to +.94. Consensus has been found among all cultures and races tested. In general, the following characteristics are considered to be beautiful: short lower face, with a short distance between the lips and the bottom of the chin; small mouth and full lips, large eyes relative to face size and thin jaws. These are all features of younger faces, and women who possess them and look younger than their actual age are judged to be more attractive than women who look their actual ages.

    Average and symmetrical faces are more attractive:

    In studies that have attempted to determine exactly what it is that is attractive about the face, researchers have generated computer composites of the human face. These faces were then superimposed on each other to create new faces. The new faces differed in the number of individual faces that made them up-from 4, 8, 16 or 32 faces. People were asked to rate the attractiveness of each composite face, as well as the attractiveness of each individual face that made up the composite. The composite faces were universally judged to be more attractive than any of the individual faces. Because superimposing faces eliminates their irregularities and makes them more symmetrical, the average or symmetrical face seems to be more attractive to humans than those that deviate from the norm.

    When researchers measured the actual symmetry in features such as foot breadth, hand breadth, ear length, ear breadth and then independently had people evaluated for their attractiveness, they found that the more symmetrical a person was, the more attractive they were considered. As people age, they become less symmetrical, so symmetry can also be a cue to age, as well as genetic imperviousness to environmental insults.

    Waist to Hip Ratio:

    Facial beauty is only part of the picture. Features of the rest of the body can also provide cues about a woman's RV. Standards for female body attractiveness vary from culture to culture along such dimensions as a plump versus a thin body, or dark versus light skin. Emphasis on particular features such as eyes, ears and genitals also varies among cultures. The most culturally variable standard of beauty seems to be plump versus slim; with cultures in which food is scarce preferring plump bodies which indicate wealth, health and adequate resources; and cultures such as the US where food is plentiful and cheap preferring slim builds.

    However, although there is variability in body size preferences among men from different cultures, they do agree on one thing; and that is the preference for a particular ratio between the size of a woman's waist and the size of her hips. Before puberty, boys and girls show similar fat distribution. At puberty, however, men lose fat from their buttocks and thighs, while estrogen causes girls to deposit fat primarily on their hips and upper thighs. The volume of body fat in this region is 40% greater for women than it is for men.

    The WHR (divide waist by hip measurement) is similar for both sexes before puberty, in the range of 0.85-0.95. After puberty, women's hip fat deposits cause their WHRs to become significantly lower than men's, with healthy reproductively capable women having WHRs between 0.67 and 0.80, whereas healthy men have a ratio in the range of 0.85-0.95. Abundant evidence shows that the WHR is an accurate indicator of women's reproductive status. Women with lower ratios show earlier pubertal endocrine activity. Women with higher ratios have more difficulty getting pregnant and those who do get pregnant, get pregnant later than those with lower WHRs. The WHR is also a long-term predictor of disease, with diseases such as diabetes, hypertension, heart attack, stroke and gallbladder disorders being linked with the distribution of fat, as reflected by ratio, not amount.

    In dozens of studies conducted by Singh, men rated attractiveness of female figures who varied in both WHR and total amount of fat. Men found the average figure to be more attractive than either a thin or heavy figure. Regardless of the total amount of body fat, however, men find women with low WHRs the most attractive. Women with a WHR of .70 are judged to be more attractive than women with a WHR of .80, etc. etc. (see C on the image on the web). Singh has also analyzed Playboy centerfolds and winners of US beauty contests over the last 30 years and confirmed that while the models and contestants got thinner over the last thirty years, both models and contestants maintained a WHR of 0.70 over the last thirty years. Cross-cultural data confirms this, even in cultures where men prefer larger women, they still find a WHR of .70 the most attractive.

    Sex Differences in the Importance of Physical Appearance:

    Because of the abundance of cues conveyed by a woman's physical appearance, and because male standards of beauty have evolved to correspond to those cues, men place a premium on physical appearance and attractiveness in their mate preferences. A cross-generational mating study spanning 57 years from 1939-1996 in the US gauged the value men and women place on different characteristics in a mate. The same 18 characteristics were measured at roughly one-decade intervals to determine how mating preferences have changed over time in the US. In all cases, across all generations, men rated physical attractiveness and good looks as more important and desirable in a potential mate than did women. Men tend to see attractiveness as important, whereas women tend to see it as desirable but not crucial.

    This does not mean that the importance of attractiveness remains fixed, in this country alone, the importance of attractiveness in a mate has increased dramatically in this century. For every decade since 1930, physical appearance has increased in importance for men and women about equally, corresponding with the rise in television, fashion magazines, advertising and other media depictions of attractive models. For example, on a scale ranging from 0-3, the importance of good looks in a marriage partner increased between 1939 and 1996 from 1.5-2.1 in men and from 0.94-1.67 in women, showing that mate preference can change. These changes point out how cultural evolution can change preferences, but the gap between men and women has remained the same, although the numbers have changed.

    In all 37 countries surveyed by Buss, regardless of location, habitat, marriage system, or cultural living arrangements, men in all 37 cultures valued physical appearance in a potential mate more than women. Men's preference for physically attractive women appears to be the product of a species-wide psychological mechanism that transcends culture.

    Do Men Prefer Ovulating Women?

    Perhaps one of the most obvious predictions one could make about men's desires is that they should show a strong preference for women at the time they ovulate. Ancestral men who were able to detect ovulating women would have several advantages over those who could not. First, they could channel courtship, seduction and sexual behavior toward women at this time, thus maximizing the odds of successful fertilization. Second, they could save a tremendous amount of time avoiding women who were not ovulating. Third, a married man could restrict his mate-guarding efforts to the time during which his spouse was ovulating.

    Most other primate males can detect when a female is ovulating and females make no secret of their ovulatory status. However, since ovulation is concealed or cryptic in humans, conventional scientific wisdom is that men cannot detect ovulation.

    However, there are several lines of evidence that suggest that men might, in fact, be able to detect when women ovulate. First, during ovulation, women's skin becomes vascularized or suffused with blood and gives them a glow or a healthy reddening of the cheeks. Second, women's skin lightens slightly during ovulation. Third, during ovulation women's levels of circulating estrogen increase, which produces a corresponding decrease in a women's waist-to-hip ratio. Fourth, one study watched women in singles bars to see how often they were touched by men. One observer recorded various behavior of each woman in the bar, including how much she was touched by men and the tightness and length of her skirt. A second member of the team approached each woman as she left the bar and interviewed her about the time of her menstrual cycle. Outside the bar, each woman was also photographed. Subsequently, the photographs were digitized and researchers calculated the amount of skin each woman displayed. Women taking the pill were analyzed separately from those not on hormonal suppression.

    Among women not taking the Pill, those who were ovulating at the time were touched by men significantly more often than those who were at other points in their menstrual cycle. Ovulating women engaged in more sexual signaling, such as showing a greater amount of skin and wearing tighter and shorter skirts. The fact that ovulating women were touched more often might mean that men can detect ovulation-it might also mean that because the women were signaling sexually, men paid more attention to them. Women not on the Pill report that they feel more sexual desire and initiate sex more often during ovulation than at other times of the month, so it may simply be that this desire is expressed as sexual signaling and men detect those cues and not actual cues for ovulation.

    In summary, we have no idea if men can detect ovulation, but they are probably sensitive to the kinds of sexual signaling that women do when they feel sexual desire, and this tends to peak at ovulation.

    Paternity Uncertainty and How to Solve It:

    Concealed ovulation dramatically changed the ground rules of human mating. Women became attractive to men not just during ovulation, but during their entire menstrual cycle. Cryptic ovulation obviously created a problem for men in terms of decreasing their paternity certainty. Because mating is not the sole activity needed for survival, women could not be guarded around the clock and the more time a man spent guarding, the less time he had available for solving other problems such as finding food.

    Marriage, of course, provided one possible solution to paternity uncertainty, with repeated contacts during the fertile phase of the spouses cycle insuring that the male was the father of their children. The social traditions of marriage provide a clear signal about who is mated to whom, thus reducing male conflict over women. For an ancestral man to reap the fitness benefits of marriage, he would have to have some kind of reasonable assurance that his wife remained sexually faithful and males should have developed mechanisms to measure fidelity. If he did not, he risked the possibility that his resources would be given to another man's children and his own fitness would be sharply reduced. Buss bluntly states that men who were indifferent to the potential sexual contact between their wives and other men are not our ancestors.

    Our ancestors could have solved this male adaptive problem by seeking qualities in a potential mate that would increase the odds of their paternity:
    1. One way they might have done this was with a desire for premarital chastity.

    2. and secondly, a desire for post-marital fidelity.

    Before the use of modern contraceptives, chastity would likely have provided a clue to the future certainty of paternity, since woman who remained chaste would likely also not engage in post-marital sex with other men.

    The value that men place on virginity has declined in the US over the last 70 years. In the 1930s, men viewed chastity as important, but in the past two decades have rated it as desirable but not crucial. On a list of 18 characteristics, it is the 17th most valued. The value of chastity varies greatly by culture also, with men in China, India, Indonesia, Iran, Taiwan and Arab countries valuing it highly, while countries such as Sweden, Norway, Finland, the Netherlands, West Germany and France believe that virginity is largely irrelevant. Some believe that this variability in the value of chastity is related to the economic independence of women. In countries where women can be and are highly independent and can economically provide for themselves, chastity seems to be less important (clearly a value that cannot be imposed on women by men if women cannot be coerced into chastity); while in countries where it is unlikely that women will be independent of men, chastity is highly valued. Differences in the economic independence of women, in the benefits provided by husbands, and in the intensity of competition for husbands may all drive this cultural variation in the importance of chastity. Where women benefit greatly from marriage and where competition for mates is fierce, women will compete with one another to signal chastity, causing the average amount of pre-marital sex to decrease. In countries where women control their own economic status, do not require so much of men's investment, and compete less, they are freer to disregard men's preferences, which causes the average amount of pre-marital sex to increase. Buss suggests that men everywhere should value chastity, but in some cultures they cannot demand it.

    From a man's reproductive point of view, virginity may serve as a cue to indicate future marital fidelity. In one study of short and long term mating in the US, it was found that American men view lack of sexual experience as desirable in a spouse. Furthermore, men see promiscuity as especially undesirable in a future marriage partner. Contemporary studies bear this out and suggest that the best predictor of extramarital sex is premarital sexual permissiveness; people who have had many sexual partners before marriage are more likely to be unfaithful than those who have had a few.

    Modern man values fidelity. When American men were asked to evaluate 67 possible characteristics for their desirability in a marriage partner, they rated faithfulness and sexual loyalty as the top two, and unfaithfulness as the least desirable trait. Cross-cultural studies have not been done.

    Finally, women seem to be aware of what men's long-term preferences are and attempt to comply or deceive men into thinking that a women has a particular attractive characteristic. Tactics such as wearing makeup to look younger and healthier, wearing clothing that accentuates a certain body shape, or hides an unwanted body shape, dieting, cosmetic surgery, and doing things like derogating a rival or competitor by calling them fat, ugly, or promiscuous, sluts, etc. are all common tactics reported by college women that they use to attract males. Clearly, women are aware of what men find attractive.

    The views and opinions expressed in this page are strictly those of the page author. The contents of this page have not been reviewed or approved by the University of Minnesota.