The Highly Contextual Nature of Human Mating Strategies
When it comes to human mating, evolutionary psychologists have cracked much of the code. The evolutionary perspective has elucidated many elements of human mating, including the nature of physical attraction,1 the nature of love,2 the interface of parenting and courtship,3 infidelity,4 relationship conflict,5 and pretty much any other aspect of human mating that you can think of. All elements of human mating follow from basic principles derived from Darwin’s big idea.
But one of the most exciting themes to emerge from all of this research is that human mating patterns are strategic, predictable (i.e., not random), and largely designed by evolutionary forces to increase reproductive payout across future generations.6 This is not to say that the evolutionary perspective predicts that all humans (or all members of any species, for that matter) are designed to create as many offspring as possible during a lifetime. In fact, from a behavioral ecological perspective, optimal patterns of offspring production within a species are capped by ecological factors.7 For women, increasing the number of sex partners decidedly does not increase the number of viable offspring who make it to reproductive age8—and for men, who live in a social world with ground rules set by females’ high levels of obligatory parental investment and high levels of discrimination in mate selection, efforts to have sex with as many women as possible usually fall quite flat. Also, individual differences play a role here. Sex drive levels certainly vary within both males and females as a function of personality, attachment style, genetics, hormones, daily stressors, time of month, culture, and many other factors. What is clear is that humans have a lot of mating strategies at their disposal, and context (both internal physiology and external factors) strongly influences which strategies are prominent at particular points in the human life span.
Indeed, human mating strategies were shaped by selection pressures to take these complex factors into account. In the original formulation of Sexual Strategies Theory, Buss and Schmitt9 advanced nine hypotheses and made 22 empirical predictions. Since then, the theory has been tested in many different ways, it has influenced related theories, and it has been extended to incorporate individual differences, sex-specific adaptive issues surrounding love and commitment, and a wider array of social, cultural, personal, and ecological variables.10
In this chapter, we discuss the complex suite of factors that underlie human mating and discuss how mating strategies may be conceptualized as residing at the core of human mating intelligence.
In terms of the psychology of human mating, mating strategies are optimized patterns of behavior that are relatively likely to lead to long-term reproductive success based on typical environments faced by our ancestors across human evolutionary history. Such strategies include, for instance, males being attracted to females who show signs of youth11 (e.g., lustrous hair, smooth skin; see Chapter 4) because such signs were correlated with fertility across ancestral contexts. Mating with women who were most likely able to produce children (as opposed to mating with women who probably could not) would clearly be an adaptive mating strategy. A female tendency to seek high levels of commitment from a partner before consenting to sexual relations would be an adaptive strategy because women benefit greatly from mating with partners who are faithful and who have the ability to provide resources for a growing family. Thus, females would be expected to screen carefully through signals of commitment—and research on the nature of female mating intelligence has found that this is exactly what they do.12
To understand the evolutionary perspective on human mating strategies, we have to understand the appropriate use of the word strategy in this context. Importantly, strategy does not, here, correspond to a conscious game plan implemented to achieve some stated goal. It would be inaccurate and inappropriate, for instance, to talk about the male tendency to desire multiple partners (relative to females’ desires)13 as reflecting a conscious effort on the part of all males to deceive women and to turn up multiple sex partners—and to destroy families across the globe along the way. Such an inappropriate interpretation would easily lead to the implication that all men are pigs. Indeed, the evolutionary perspective explains the urge to do so, but there are certainly good men who use their conscious capacities to override their instincts and minimize hurting others and getting hurt themselves.
Therefore, when evolutionary psychologists refer to a strategy, they are typically talking about a behavioral pattern that is largely unconscious in nature. Thus, evolutionary psychologists might talk about tendencies that are common in males across cultures regarding desiring multiple partners—but that is very different, of course, from saying that men across all cultures consciously choose to be pigs. Many of the unconscious forces that pull us toward certain stimuli and repel us from other stimuli are at times quite potent and are predictable from an evolutionary perspective. This chapter is all about those unconscious strategies that evolutionary psychologists are at the forefront of understanding. Once you start reverse-engineering the human mind, you discover just how intricate and intelligent these forces really are.
Although the evolutionary origins of human mating are addressed in our introductory chapter, we believe it’s important to revisit these basic issues here because they are particularly pertinent to our understanding of human mating as strategic. The evolutionary roots of human mating strategies are perhaps best understood in terms of Robert Trivers’14 theory of parental investment. Trivers, trained at Harvard as a biologist in the 1960s, has become one of the world’s leading voices on the topic of evolution. He has been particularly lauded for the powerful nature of his theories and their ability to generalize to explanations of humans. His theory of parental investment may well be evolutionary theory sine qua none in the field of evolutionary psychology.
Interestingly, parental investment theory was not designed as a theory about humans at all. In fact, this theory was initially conceptualized as an explanation of parenting across species. In some species, such as robins, offspring are particularly altricial—the young are helpless at birth and need a lot of assistance. So much so, in fact, that multiple adult helpers are nearly required for the young to get enough in the way of worms to reach adolescence. In such a species, it would make sense that adults would form pair-bonds and would both contribute to raising offspring—such a species-typical arrangement would benefit not only female robins (who secure nice, helpful, dad-like partners) but also male robins, who benefit from siring offspring that don’t die horrible deaths in their first few days and who, rather, grow up to reach adulthood and become successful in the mating domain themselves. When these ecological conditions are met, and parental costs are relatively high, long-term mating strategies should come to typify the species. Thus, the pair-bonds that robins form each spring—along with their beautiful songs brought us all summer long—provide the prototype of long-term mating.
Not all species have young that require intensive help from multiple adults. White-tailed deer, which, like robins, are prevalent in so many regions of North America, give birth to young who typically can walk during their first day of life (they are, thus, precocial). Like all mammals, the young seek proximity to their mothers for the first several months of life, being fed exclusively by her for quite a while. So here we have a case of a species for which obligatory parental investment is relatively low. A fawn needs help from fewer adult conspecifics than does a robin hatchling. Guess what? Bucks don’t get married or settle down. In deer, mating is typified by short-term strategies—efforts to choose high-quality mates coupled with zip in the way of expectations of long-term pair-bonding.
Trivers’ great insight, thus, is this: In species in which parental investment is high, long-term mating systems are expected to evolve. In species in which parental investment is low, short-term mating systems are expected to evolve.
Where are humans on this continuum? Good question. Well, without a doubt, human offspring are altricial. A newborn human needs at least as much adult help as does a robin hatchling. If you’re a parent, you do not need us to tell you that.
So with humans, we have a relatively altricial species and relatively high levels of parental investment required for individuals to ultimately rear offspring that are capable of ultimately reproducing (successfully) themselves. Based on this reasoning, it is little wonder that human cultures are permeated with variants of monogamy. As a species, humans are long-term strategists.
One of the most prominent areas of research in evolutionary psychology—and one of the most controversial15—pertains to work on sex-differentiated behavioral patterns between men and women in the mating domain. Study after study that examines differences between the sexes in mating-relevant behavior has found important differences that are generally consistent with predictions based on the evolutionary perspective.
Although long-term mating strategies definitely characterize human mating in a general sense, research does suggest that it is appropriate to differentiate between a specific male mating psychology and a specific female mating psychology.16 Importantly, just as differences among mating systems of different species can be well understood in terms of Trivers’ theory of parental investment, differences between the sexes (within a species) can also be understood in terms of parental investment.
In most sexually reproducing species, females invest more in parenting than do males. This point partly is made necessary by the fact that the biological definition of the female of any species is the sex that has the larger gamete (referred to as the egg). Contributing the larger gamete to offspring (in other words, being female) sets the stage for relatively high parental investment. Eggs provide developing zygotes with all the nutrition needed in the earliest stages of life. Sperm cells generally simply activate the egg and start the process of fertilization. They do not contribute to the nutritional resources of the developing zygote. As a result of this biology, females in most sexually reproducing species17 tend to have higher obligatory parental investment than do males.
In humans, the idea of females having relatively high obligatory parental investment compared with males is apparent in many facts. At the gamete level, the egg is considerably bigger than is the sperm—and sperm are considerably more common. Females release approximately 350 eggs in a lifetime; males release approximately half a billion sperm cells in a single ejaculate. For males, the physiological costs of pregnancy are nonexistent. For females, these include dramatic effects that bear on all bodily systems and that have potentially dangerous consequences. In all societies (especially pre-westernized societies),18 childbirth is a significant cause of death of women (but, obviously, not of men). In pre-westernized societies, women tend to nurse children through about 3 years. Men do not. Even beyond the very early years, when women, across cultures, spend a disproportionate amount of time in childraising relative to men, women still expend more energy on parenting compared with men. And this sex difference holds true for grandmothers versus grandfathers, as well.19
In our species, women invest more in parenting than do men. Further, given how altricial human newborns are, child care provided by multiple adults offers an important advantage on the road to survival and reproductive success. According to Trivers’ theory of parental investment, then, women, on average, should be more likely to utilize long-term strategies compared with men. In an unconscious effort to reproduce most effectively, optimal female mating strategies would include efforts to secure high-quality mates that are (1) faithful and monogamous, (2) able to provide material resources for offspring, and (3) likely good and kind in the domain of parenting and relationships.
Research on this topic bears these predictions out. In a study with thousands of young adults across more than 30 cultures, David Buss and colleagues20 found that, regardless of geographic region, women consistently rate education, ambition, intelligence, and kindness as crucial in potential mates. These qualities clearly are features that would be highly desirable in a long-term mate. In follow-up research in this same area, Li21 found that women who are told to imagine that they have a limited mating budget tend to emphasize these same kinds of qualities. In this research, participants are given a certain amount of mating budget dollars—either an extravagant or a highly restricted budget. They then allocate mating dollars to different qualities based on how important these qualities are (e.g., 5 mating dollars on looks, 3 on wealth). With a large budget, males and females come out as very similar—wanting all good features regardless of whether they’re looking for long-term or short-term mates. However, we see something very interesting in the restricted budget conditions—in such conditions, men allocate a disproportionate amount of dollars to attributes related to physicality, and women allocate a disproportionate amount to markers of wealth, status, trustworthiness, and resource-acquisition ability. Li’s22 big insight is that core sex differences in mating strategies emerge under restricted budgetary conditions. Under such conditions, females trade off looks for status and security.
Another important element of female mating psychology has to do with choosiness and relative discrimination when it comes to mate selection. In recent years, several studies have used a speed-dating paradigm to create an ecologically valid microcosm of human mating in action. In a particularly intensive study done in this way, Penke, Todd, Lenton, and Fasolo23 found that women are much more discriminating than men—being about half as likely to agree to a second date to any particular individual compared with men. In fact, a great deal of prior research bears this prediction out—in humans24 as well as a host of other species in which females are relatively high in parental investment compared with males.25
In fact, female mating strategies across the gamut of the mating domain seem to speak to a general long-term strategy that typifies female mating psychology. As mentioned earlier, female mate preferences seem to be honed to draw women to faithful, honest, intelligent men who can provide for their young.26 Deeper into a relationship, there’s further evidence that women are relatively sensitive to a partner’s investment of time and emotional resources.27 In addition, when it comes to infidelity, there is evidence that females are more concerned about partners cheating in an emotional fashion (e.g., falling in love with another) compared with males.28 This makes sense from an evolutionary perspective because a male partner who falls in love with another may be showing signs of withholding resources from a mate and her children. Although both men and women have both long-term strategies and short-term strategies at their disposal (and do use both strategies), compared with men, women (on average) tend to primarily employ long-term mating strategies.
Two major forces bear on male mating strategies. First, given the fact that women are highly discriminating in the mate-selection process,29 women are the gatekeepers of human mating, and males must deal with the fact that females set the ground rules. A second point to consider is the fact of relatively low obligatory parental investment associated with being male. So, although all human males are part of a species with high parental investment costs and altricial offspring, compared with females, males are the lower-investing sex (in terms of obligatory parental investment).
Given these factors in combination, males should be biased toward relatively short-term mating strategies (compared with females), but they should, in important ways, be biased toward long-term mating as well (because women, who are generally armed with long-term mating strategies, set the ground rules).
Being prone to short-term mating strategies seems to be manifest in several features of male mating psychology. In a classic study on this topic, male and female college students were approached by an attractive member of the opposite sex (really a psychology research confederate)—who, at random, asked one of three questions: (1) Will you go on a date with me? (2) Will you come back to my apartment? or (3) Will you have sex with me? For the question about the date, males and females both showed a 50% hit rate—half the men asked and half the women asked, consented. The other questions may be taken as a proxy for proclivity toward short-term sex—and the data were clear. For the apartment question, 6% of women consented, compared with 69% of men. And for the sex question, none of the women consented, compared with 75% of the men.30 These results were replicated soon after the first study.31 Of course, college women may have desired an encounter just as much as men, but because of societal expectations at that time, women may have been under more pressure to say no. Thankfully, there have been many more studies conducted since then to assess the extent to which males, on average, are tilted toward a short-term mating orientation.
A much more recent study aimed to replicate the original study conducted by Russell Clark and Elaine Hatfield, but also to go beyond it by looking at additional factors, such as the influence of age, relationship status, confederate attractiveness, and type of sexual invitation.32 In this study, 389 participants (173 men and 216 women) from Denmark were approached outdoors either at a university campus, a pedestrian area, or a park area between the hours of 11:00 a.m. and 5:00 p.m. during a 2-day period. Twenty-one, moderately attractive first-year psychology students (11 women and 10 men; the “confederates”) approached a stranger of the opposite gender and said: “Hi, my name is _______. I am sorry to disturb you like this, but I have been noticing you around and find you very attractive.” The confederate then asked one of three questions: (1) “Would you go on a date with me tonight or during the week/weekend?” (2) “Would you come over to my place tonight or during the week/weekend?” or (3) “Would you go to bed with me tonight or during the week/weekend?”
The confederates were told to only approach strangers who were walking by themselves and whom they could imagine would follow through on their request. Each confederate approached up to 30 subjects during a 2-day period. After participants received the request from the confederate, they were approached by one of the other members of the research team, were told about the purpose of the study, and were asked to anonymously disclose their age, current relationship status, and awareness of the point of the study and to rate their own attractiveness as well as the attractiveness of the confederate on a nine-point scale.
Their results were very similar to those of the Clark and Hatfield study.33 Men, on average, responded more favorably to the two most sexually explicit invitations than women did. There was also an effect of confederate attractiveness, but only for females. Men did not seem to be much swayed by physical attractiveness differences; as long as the female was of moderate level of attractiveness, the males tended to accept the invitation for an immediate sexual encounter. The researchers argue that the finding that females were more likely to accept a sexual invitation of an attractive stranger is consistent with the Good Genes Hypothesis, which states that women are more likely to engage in causal sex with men who exhibit traits (such as physical attractiveness, creativity, etc.) that signal they have a genotype that contributes to offspring viability or reproductive success.34
The researchers additionally found an effect of relationship status. Males who were not in a relationship were 20 times more likely to consent to one of the sexual invitations compared with males who were involved in a relationship. Here, there were relative gender differences: females who were not in a relationship were more than 8 times more likely to consent to one of the sexual invitations compared with females who were in a relationship. When they stratified the entire sample by relationship status, they found that the overall percentile rates for both men and women who were not in a relationship were not significantly different from the aggregated findings of Clark and Hatfield35 and Clark.36 In sum, different time periods (1990 vs. 2010) and different locations (U.S. college-aged participants vs. Denmark college-aged students) found the same basic findings.
Since the Clark and Hatfield study, psychologists have accumulated an exceptionally large body of evidence across multiple continents, across a wide range of age groups, and using extremely large samples, to suggest that males, on average, have a higher desire for sexual variety than females. Here are some of the most notable findings37:
1. Men across the globe in 48 nations report an interest in having more lifetime sex partners compared with women.38
2. Men in 53 nations show higher levels of sociosexuality (a proxy for promiscuity) than women, and women were more variable than men in their sex drive.39 Although gender equality predicted sex differences in sociosexuality, the extent to which the culture was equitable did not affect sex differences in sex drive.
3. Men select more partners in a speed-dating context.40
4. When asked how early in a relationship it would be okay to have sex, men’s answers came in much earlier compared with women’s answers.41
5. Men report more reasons for having sex, and their reasons centered more on physical appearance and physical desirability (“The person had a desirable body”), experience seeking (e.g., “I wanted to increase the number of partners I had experienced”), mere opportunity (e.g., “The person was ‘available’”), pure physical pleasure (e.g., “I was horny”), utilitarian reasons (“to improve my sexual skills”), and social status (“I thought it would boost my social status”) than females.42
6. Men are more likely than women to engage in extradyadic sex (i.e., sex outside of a relationship).43
7. Men are more likely than women to be sexually unfaithful multiple times with different sexual partners.44
8. Men are more likely than women to seek short-term sex partners who are already married.45
9. Men are more likely than women to have sexual fantasies involving short-term sex and multiple opposite-sex partners.46
10. Men are more likely than women to pay for short-term sex with (male or female) prostitutes.47
11. Men are more likely than women to enjoy sexual magazines and videos containing themes of short-term sex and sex with multiple partners.48
12. Men are more likely than women to desire, have, and reproductively benefit from multiple mates and spouses.49
13. Men desire larger numbers of sex partners than women do over brief periods of time.50
14. Men are more likely than women to seek one-night stands.51
15. Men are quicker than women to consent to having sex after a brief period of time.52
16. Men are more likely than women to consent to sex with a stranger.53
17. Men are more likely than women to want, initiate, and enjoy a variety of sex practices.54
18. Men have more positive attitudes than women toward casual sex and short-term mating.55
19. Men are less likely than women to regret short-term sex or “hook-ups.”56
20. Men have more unrestricted sociosexual attitudes and behaviors than women.57
21. Men generally relax mate preferences (whereas women increase selectivity for physical attractiveness) in short-term mating contexts.58
22. Men perceive more sexual interest from strangers than women do.59
To be sure, there have been studies here and there that seem to contradict this overall pattern of results, and each of the studies reviewed in this section has some methodological limitations (there is no perfect study). Even so, all of the research taken together points to an inescapable conclusion: compared with females, males, on average, are more likely to demonstrate short-term mating strategies. With that said, these are average group differences and mask a lot of variability in behavioral outcomes. In addition to documenting these overall sex differences, the most recent cutting edge research also suggests that both male and female mating strategies are highly contextual, vary quite a bit within each sex (although males may be more variable in terms of number of sexual partners),60 and in many cases, are more similar than dissimilar. In the rest of this chapter, we discuss the evidence for these important points.
From an evolutionary perspective, men and women are only expected to differ in areas where they faced recurrently different adaptive problems over evolutionary history (e.g., the biological consequences of short-term mating). This means that they are expected to be similar in all areas where they faced similar adaptive problems. According to Buss and Schmitt, “Although the final scientific word is not yet in, we suspect that the similarities outnumber the differences.”61
Mating researchers have developed a reputation for documenting sex differences in behavior. Sex differences are interesting, important, and have significant effects on many aspects of human life. And sex differences in human mating behavior have been documented by a dauntingly large set of studies across the past several decades.62 But this all needs to be tempered by a fact of human cognition: the human mind seems to be prepared to see differences more easily than similarities.63 Perhaps psychological researchers are more likely to, accordingly, focus on differences than on similarities.
In fact, much of the same research that documents differences between the sexes documents similarities as well. It’s often forgotten, but in the classic Clark and Hatfield64 study on short-term mating we just mentioned, males and females were equally as likely to consent to an offer of a date from an attractive member of the opposite sex. Also, even though Cindy Meston and David Buss65 found that men gave more reasons for having sex than women, there still was quite a lot of similarity among the sexes: 20 of the top 25 reasons given for having sex were identical for both men and women! Also, no sex differences were found in their two subfactors relating to emotional reasons for having sex: Love and Commitment, and Expression (even though at the item level, women did endorse more emotional motivations for sex). As the researchers note, this finding counters the stereotype that men always want sex detached from emotion and “supports a growing body of clinical evidence suggesting that both men and women at times desire intimacy and emotional connectedness from sexual activity.”66
In another study looking at the link between sexual motivations and sexual satisfaction, Kyle Stephenson, Tierney Ahrold, and Cindy Meston67 found that love and commitment motives were positively correlated with satisfaction for both men and women and that having sex to boost self-esteem and gain resources were negatively associated with satisfaction for both men and women. Therefore, men and women show a lot of similarities in terms of what makes them sexually satisfied.
Among college samples in the United States, similarities between the sexes may be particularly pronounced. A recent study found that modern-day college-aged men and women invest the same amount of mating effort toward short-term mating and that both lower their standards for sex partners the same amount.68 These results suggest that today’s college-aged men and women may be a lot more similar than different when it comes to mating orientation, at least in the United States (see Chapter 9 for more discussion on the possible causes for the increase in hook-up behaviors found among college students in the United States).
Another recent study focusing on college students also found many similarities between men and women in willingness to engage in a short-term sexual encounter.69 Psychologist Terri Conley argues that a major confound inherent in the original Clark and Hatfield study is that female participants were judging whether they wanted to have sex with men, whereas male participants were judging whether they would want to have sex with women. According to Conley, “by considering the gender of the participants independently of the gender of the proposer, one may overlook crucial information about the reasons behind the gender differences in casual sex.”70 To overcome this potential confound, Conley conducted a series of studies in which her focus was on the perceived characteristics of the proposer.
Looking just at the likelihood of accepting casual sex proposals from the participant’s own life experiences, men accepted the casual sex offer 73% of the time, whereas women did so only 40% of the time. These overall gender differences are consistent with the original Clark and Hatfield studies, although they do suggest that in thinking about hypothetical naturalistic sexual scenarios, women are much more likely to accept offers of casual sex. Also, lesbian women were equally as likely to accept a casual sex offer as men were, and bisexual women were more likely to accept an offer from a woman than from a man.
Above and beyond these overall gender effects, Conley found a number of interesting contextual findings that extend the original Clark and Hatfield study. First, she found that males who approached women for a sexual encounter were uniformly perceived as less desirable compared with females who approached men. Such “approaching” men were perceived by women as more physically dangerous and as less likely to provide them sexual satisfaction. They were also perceived as having relatively low status and as being cold individuals. This finding suggests that the gender differences found in the Clark and Hatfield studies may have been strongly influenced by the gender of the proposer in addition to the gender of the receiver, with perception of risk being an important factor.71 Of course, gender differences in risk perception may still be an evolved difference, with the risk perception difference being the proximate means by which the ultimate function is achieved.72
Conley also found a number of situations in which male and female college students were equally likely to engage in a short-term affair. Conley investigated how much familiarity could reduce these effects. Using stories of famous people, the participant’s best opposite-sex friend, and strangers, she found that women (but not men) perceived less risk from the familiar individual making the sexual proposal than from a stranger. When women considered the familiar (and thus less risky) proposer, they were just as likely to agree to casual sex as men were.
While testing the importance of familiarity as a variable in mating, Conley found that men were as unlikely to accept an offer from Roseanne Barr as women were to accept a sexual offer from Carrot Top or Donald Trump. Regardless of how rich and successful these individuals are, they just weren’t considered sexually attractive! This finding is consistent with Sexual Strategies Theory because women wouldn’t be expected to be as interested in resources for short-term mating and would be more interested in indicators of good genes. The familiar man who the women did (hypothetically) agree to have a short-term encounter with is Johnny Depp—someone clearly with many good genes! The good genes of Johnny Depp probably would have given women pleasure. That women weren’t as interested in Carrot Top is interesting in light of our argument in Chapter 2 that good humor ability is an indicator of good genes. Perhaps the women in the sample didn’t find Carrot Top particularly funny! Likewise, Roseanne’s humor ability wasn’t good enough to overshadow her less than stellar physical attractiveness. Men preferred to sleep with Christie Brinkley and Angelina Jolie instead—not a huge surprise.
We must stress that this sample consisted of college-aged students who, as a group, were probably not as interested in finding a long-term mate with earning potential than they were in sexually experimenting and having pleasure. Older female samples may find Carrot Top and Donald Trump more enticing propositions (although see the section below on age effects)! Taking all the results together, Conley suggests that “for women, feeling ‘safe’ contributes to their likelihood of accepting a sexual offer, which is why familiar proposers are more likely to receive favorable responses to their sexual proposals than unfamiliar proposals.”73
Across studies involving actual and hypothetical sexual scenarios, Conley also found that men and women were equally likely to accept an offer of casual sex if the approacher was perceived as sexually capable (i.e., “good in bed”). Therefore, anticipated pleasure may be a stronger predictor of short-term sexual engagement than the sex of the participant. This is consistent with pleasure theory,74 as well as evolutionary psychology, because gender differences in pleasure (like risk) may be the proximate means by which the ultimate function is achieved.75 Therefore, in the real world, women on average may accept fewer offers of casual sex than men because they think they will be less likely to experience pleasure from such an encounter. Indeed, as Conley notes, this assumption may not be unwarranted because research does demonstrate that women have orgasms only 35% as often as men do in a first-time casual sexual encounter situation.76
Conley’s clever studies suggest that college-aged men and women are equally as likely to accept a short-term sexual invitation if the person doing the approaching is a gorgeous celebrity, the perceived risk of the person doing the approaching is low, and there is high anticipation that pleasure will ensue from such an interaction. Importantly, Conley also found that women were much more likely to agree to have sex with Johnny Depp than a complete stranger, whereas men were only slightly more likely to agree to have sex with Angelina Jolie than a complete stranger. These results are similar to those from a study conducted by Schützwohl and colleagues77 who found among a sample of men and women from three countries (Germany, Italy, and the United States) that physical attractiveness had a much greater effect on women’s than on men’s willingness to accept an explicit offer for casual sex. These findings are quite consistent with a Sexual Strategies Approach but also show specific proximal conditions that may cause men and women to be more likely to agree to a short-term sexual encounter.
Along similar lines, Pamela Regan78 found that when it comes to a casual sex partner, both men and women undergraduates were most willing to compromise intelligence and social status but were unwilling to compromise physical attractiveness; and when considering a romantic partner, both men and women were least willing to compromise on interpersonal skill and responsiveness and were most willing to compromise on social status. When it comes to short-term flings, the data are in: both men and women are highly likely to consent if the person is physically attractive (shocking, we know!). So, amidst reporting of sex differences, it is sometimes too easy to ignore the great amount of overlap that exists among the sexes.
When it comes to the long-term, the data are even clearer: men and women want the same things. Research on mate-selection factors and personality in the mating arena suggests that males and females, on average, converge considerably in factors that they prioritize in seeking mates. Kindness, mutual love, sense of humor, and intelligence are considered among the most important features of a potential long-term mate for both men and women—and this fact has been documented clearly across 37 disparate cultures.79
A recent study including nearly 300 young adults also showed marked similarities in the sexes regarding many facets of human mating. In this study,80 men and women showed no significant differences in the following:
• How much overall distress they experienced thinking about their partners cheating sexually
• How much distress they experienced thinking about their partners cheating via vaginal versus oral sex
• How much distress they experienced thinking about their partners cheating with a friend versus a stranger
• How much distress they experienced thinking about their partners using a condom or not in an instance of infidelity
The bottom line of this study is that people tended to be more distressed by thoughts of their partners cheating with someone from their intimate social circle compared with a stranger—and this effect replicated across the sexes. The researchers interpreted these findings as showing that one of the main evolutionary costs of infidelity pertains to adverse consequences to one’s social bonds, beyond the obvious adverse effects to one’s pair-bond. Relevant to the point at hand, the sexes responded very similarly to one another.
It’s rarely been stated, and may seem relatively uninteresting to some, but we think this point is extremely important for understanding human mating intelligence: males and females show considerable similarities in nearly all areas of the mating domain.
Sex differences may also mask important differences within each sex. As we mention repeatedly throughout this book, individual differences are essential to the mating intelligence framework. Humans vary among one another in their sexual preferences and behavior. Consider the fact that people differ quite a bit in their motivations to have sex.81 In the Meston and Buss study we mentioned earlier,82 the researchers found 237 reasons why male and female college students have sex! They condensed the reasons down to 4 broad factors and 13 subfactors.
The first broad factor was Physical Resources, which consisted of Stress Reduction (e.g., “I was frustrated and need relief”), Pleasure (e.g., “It feels good”), Physical Desirability (e.g., “The person had an attractive face”), and Experience Seeking (e.g., “I was curious about sex”). The second broad factor was Goal Attainment, which consisted of Resources (e.g., “I wanted to get a raise”), Social Status (e.g., “I wanted to be popular”), Revenge (“I wanted to get back at my partner for having cheated on me”), and Utilitarian reasons (e.g., “I wanted to get out of doing something”). The third broad factor was Emotional, which consisted of Love and Commitment (e.g., “I wanted to feel connected to the person”) and Expression (“I wanted to welcome someone home”). The fourth and final broad factor was Insecurity, which consisted of Self-Esteem Boost (“e.g., “I wanted to feel powerful”), Duty/Pressure (e.g., “I didn’t know how to say ‘no’”), and Mate Guarding (e.g., “I wanted to keep my partner from straying”).
Some of the top reasons for having sex for both men and women included “I was attracted to the person,” “It feels good,” “I wanted to show my affection to the person,” and “I was horny.” As the researchers noted, the less frequently endorsed reasons for having sex are equally as important. Some of the most infrequent responses for both men and women included “I wanted to give someone else a sexually transmitted disease (e.g., herpes, AIDS), “Someone offered me money to do it, “I wanted to get a raise,” “It was an initiation rite to a club or organization,” “It would get me gifts,” “I wanted to punish myself,” “I wanted to feel closer to God,” “I wanted to be used or degraded,” “I wanted to break up a rival’s relationship by having sex with his/her partner,” and “I felt sorry for the person.” We don’t yet know what traits or life experiences predict these kinds of responses.
The researchers analyzed the personality variables that predicted the various factors. The more extraverted the woman, the higher she tended to score on the Pleasure subfactor. The more disagreeable, less conscientious, and neurotic the woman, the higher she tended to score on all four broad factors. Interestingly, there was no relation between openness and any of the factors or subfactors among women. Unsurprisingly, the more unrestricted the women’s sociosexuality (the more she reported a short-term mating strategy), the higher she tended to score on every single factor and subfactor except for one exception: the Love and Commitment subfactor. The strongest correlates of sociosexuality (an orientation for short-term mating) for women related to Physical Resources: stress reduction, physical desirability, experience seeking, and pure physical pleasure (which is consistent with the Conley study mentioned previously).
For men, there were less meaningful individual differences than for women, but some still existed. Although extraversion and neuroticism did not correlate with any of the factors or subfactors among males, agreeableness was associated with the Emotional factor and the Love and Commitment subfactor. Lower levels of conscientiousness were associated with the Duty/Pressure subfactor, and openness was associated with reduced levels of Social Status and higher levels of Love and Commitment. Sociosexuality was associated with the Physical, Goal Attainment, and Insecurity broad factors, but not the Emotional factor. As the researchers note, the relations between personality and reasons for having sex may be more apparent among women than men because of the gender appropriateness of sexual promiscuity in our culture.
Meston and Buss’s work may be interesting in light of Robert Sternberg’s theory of love as a story.83 According to Sternberg, each of us creates a love story unconsciously at a young age. As we age, our relationships, and the type of people we are attracted to, tend to be influenced by these stories. Sternberg identified 26 love stories, from the fantasy fairy tale story to the war story. Perhaps many of Sternberg’s love stories are associated with the different reasons for having sex that Meston and Buss document. For instance, maybe those who are attracted to a war love story are also the ones who tend to have sex purely for goal-attainment purposes. This is pure speculation, but we think this would be an interesting future line of research.
Another important individual-differences variable that affects mating strategy is intelligence. As we mentioned earlier, the parental investment theory predicts (among other things) that men, on average, will have more of a short-term mating orientation than women and that women, on average, will care more about financial resources in a long-term mate than men. But are these effects just as strong for women who have greater access to resources and therefore not as high of a biological cost if they become pregnant?
Christine Stanik and Phoebe Ellsworth84 found that verbal SAT scores were negatively related to college-aged women’s reported desire for a man with resource-earning potential. In another study, they replicated this finding but also found that as women’s verbal intelligence increased, the more college-aged women tended to favor uncommitted sexual encounters and the less they reported adhering to and supporting traditional gender roles in marriage that view the man as provider and the women as caretaker.
Although these results must not be generalized too far because of their restricted sample (college females), they still point to the potentially moderating effect of intelligence on a women’s mating psychology. Further research should try to pinpoint exactly why intelligence has an effect. Does it have to do with the enhanced ability for prioritization that high intelligence affords? Does it have to do with increased access to career opportunities? What about men? How does higher intelligence affect a man’s mating strategy and views of traditional gender roles in marriage? Do these results replicate across a wide range of ages, and not just in college students? These are the sorts of questions that can be pursued from a mating intelligence perspective.
Another important individual-differences variable is how much shame a person feels reporting sexual fantasies. Cultural and familial expectations can strongly influence reporting on a psychological experiment. To investigate this issue, a recent study had college students click a golf tally every time they thought about food, sleep, or sex over the course of a full week.85 Men, on average, thought about sex more than women (about once an hour, or less than 19 times a day, compared with once every 2 hours for women). Although there was variability among both males and females (ranging from single-digit weekly totals to reports in the thousands), males did show greater variability in how much they thought about sex. Also, even though men did think more about sex, they also thought more about food and sleep.
Interestingly, social desirability and erotophilia (the extent to which a person responds to sexual cues and is comfortable sexually) were significant predictors of frequency of sexual cognitions for women, but not for men, and overall, erotophilia was a better predictor of frequency of sexual cognitions than the sex of the participant. The researchers argue that these findings suggest that culture exerts a strong influence on the reporting of sexual fantasies, with culture exerting more of an influence on women than men. Further research should control for these two variables when looking at sexual fantasy differences among males and females.
Yet another important individual-differences variable is attachment style. John Bowlby’s attachment theory revolutionized developmental psychology and our understanding of parent-child relationships.86 As brilliant as his theory was, he was missing one crucial component. Focusing entirely on the role of attachment for survival, he completely ignored the roles the attachment system plays in reproduction. This is understandable because Bowlby focused on infant attachment, and obviously infants are not interested in reproducing. The game changes, however, when we start looking at stages of development that involve the struggle for reproduction.
Modern evolutionary psychologists, building on Bowlby’s important work but incorporating Darwinian principles of sexual selection, conceptualize the attachment system as evolving for two related but distinct adaptive reasons: survival and reproduction. Certainly, adult attachment styles serve a different function than childhood attachment styles. In children, attachment styles help elicit care from parents in order to survive, whereas in adults, attachment styles serve to maintain long-term pair-bonds that can increase reproductive success.87
Although other drives surely come into play in adult relations (e.g., sexual attraction), the evidence suggests that the motivational system that underlies parent-infant bonds may have been at least partially co-opted during the course of human evolution to promote long-term bonding in an adult context. The attachment system is closely linked to the stress response system and helps regulate a child’s feelings of distress, pain, fear, and loneliness, with secure attachment buffering external sources of stress to some degree, and with secure and insecure infants showing different types of stress responses to separation. Some research has investigated the link between stress responsiveness and romantic attachment in adults, and the results so far seem to be consistent with those found in children.88
Securely attached individuals have fewer problems with intimacy and worry less about being alone or being rejected by others. In contrast, there are two types of insecure attachment. Those with an anxious-preoccupied insecure attachment style are inclined to increase their signaling of need and distress, show a constant preoccupation with the presence and availability of attachment figures, and tend to be clingy. An anxious-preoccupied attachment style predicts a mix of impulsive sexual attitudes, early age of intercourse (mostly for women), and intense desire for intimate, committed relationships. Anxious-preoccupied adults show higher dependency and are powerfully motivated to search for exclusive, intimate relationships.
Those with a dismissive-avoidant attachment style tend to show higher levels of self-reliance, a reduced signaling of need for others, and a distancing, detached attitude toward parents or partners. In children, avoidance is related to aggression, antisocial behaviors, and inflated self-esteem. In adults, avoidance is related to low commitment in romantic relationships, avoidance of intimacy, higher levels of sexual coercion, and a more promiscuous, sexually unrestrained orientation.89 Dismissive-avoidant attachment bears the hallmark of a low-parenting strategy, favoring short-term relationships over intimate, long-term bonding.
Now consider the well-replicated finding that men, on average, are more likely than women to find sexual infidelity more distressing than emotional infidelity.90 A recent study on an undergraduate sample of 99 men and 317 women replicated this finding, but also found interesting relations between attachment style and reaction to jealousy that went beyond the biological sex of the individual.91
These investigators found that men, on average, were between 3 and 4 times more likely than women to report greater sexual jealousy compared with emotional jealousy, thus replicating the already well-documented finding of sex differences in reaction to jealousy. But here is where things get interesting. They also found that both men and women with a secure attachment style tended to find emotional infidelity more distressing than sexual infidelity, whereas both men and women with a dismissive-avoidant attachment style tended to find sexual infidelity more distressing than emotional infidelity. Therefore, attachment style predicts reaction to jealousy.
Does this make the sex differences they did find irrelevant? No! They found that biological sex and attachment style each made independent predictions on reported reaction to jealousy. Also, although they found small sex differences in the secure and anxious-preoccupied attachment style groups, they found sizeable sex differences in the dismissing-avoidant and fearful-avoidant attachment style groups, with fearful-avoidant men being roughly 5 times more likely than fearful-avoidant women to experience greater sexual jealousy compared with emotional jealousy and dismissing-avoidant men being 26 times more likely than dismissing women to report experiencing greater sexual than emotional jealousy. Just comparing a dismissing-avoidant attachment style with a secure attachment style within each sex, the researchers found that dismissing-avoidant women were roughly 4 times more likely than securely attached women to report greater sexual than emotional jealousy, whereas dismissing-avoidant men were nearly 50 times more likely than secure men to report experiencing greater sexual than emotional jealousy!
These findings are quite consistent with other recent studies. For instance, Marco Del Giudice92 analyzed the combined results of 113 samples (66,132 participants) on romantic attachment from various countries and found that overall, males showed higher levels of a dismissive-avoidant attachment style and lower levels of an anxious-preoccupied attachment style than females. Sex differences in an anxious-preoccupied style peaked in young adulthood, whereas sex differences in a dismissive-avoidant attachment style increased throughout the life course, with men being even more likely to be avoidant in relationships compared with women as people age.
Ample other research suggests that attachment style predicts sexual behaviors above and beyond the effects of gender. Birnbaum93 found that an anxious-preoccupied attachment style predicted frequency of submissive sexual fantasies. Anxiously attached women were also particularly likely to report fantasies of sexual relations with partners other than their current partner, whereas anxiously attached men were particularly likely to report romantic fantasies. Those with a dismissive-avoidant attachment style reported less romantic fantasies.
Another study found that attachment style predicted actual extradyadic involvement (i.e., infidelity), but that the effect depended on gender.94 Overall, undergraduate females reported more intimacy motivations than males, and males reported more casual motivations than females. Additionally, there was an interaction with attachment style. Dismissive-avoidant males had the most extradyadic partners over the prior 2 years relative to all other groups, whereas preoccupied-anxious females reported more partners than secure females.
What is going on here? Why do men and women tend to become insecurely attached in different ways? Del Giudice95 presents an intriguing hypothesis. Because males have less at stake, reproductively speaking, from sexual intercourse, it is predicted that males living under conditions of high environmental stress will show higher levels of avoidance than females, which is part of a low-investment, low-commitment strategy. Anxiety, on the other hand, may be a way for females living under the same environmental conditions to secure and extract investment from both family members and sexual partners. These differences, however, should only emerge at key points in development that are related to sexual development. In support of this prediction, research does show that insecure attachment in juvenility predicts the early appearance of flirting and sexual contacts, even in prepubertal children.96
To succeed in mating, an organism needs to out-compete same-sex rivals and attract members of the opposite sex. For males, this involves status-seeking displays of dominance and aggression or investment in traits and displays that are attractive in short-term mates, such as humor, intelligence, and creativity (see Chapter 2). For females, this may involve relatively more investment in forming alliances, increasing displays of physical attractiveness, and becoming popular.
Therefore, different styles of insecure attachment may be conducive to social status, depending on one’s sex. Because avoidant attachment is related to traits such as aggression and inflated self-esteem, it may be part of a status-seeking strategy for young insecure males living the fast life. Such a strategy would center on mating effort, early reproduction, and selfish risk taking. For females, dependent and closeness-oriented behaviors may be advantageous in female group relationships. Some researchers have suggested that anxious attachment in females may relate to relational and indirect aggression, which makes evolutionary sense in the context of female peer competition. This hypothesis hasn’t been directly tested yet, however.
According to this theory, the mechanisms regulating strategic variation are sex differentiated, and the same cues may exert quite different effects, depending on the person’s sex. A key environmental variable that affects this sex difference is the level of stress and risk in the environment. At moderate levels of risk, it is predicted that insecure males (but not females) will adopt short-term strategies; but under high levels of risk, it is more evolutionarily adaptive for both males and females to adopt a short-term mating, low-parenting strategy.
The implications here are huge, not just for our understanding of the development of attachment styles but also for our understanding of sex differences in sexuality, dominance seeking, aggression, trust, cooperation, and risk taking. For more on Del Giudice’s hypothesis and to get a sense of the multiple viewpoints in this debate, check out Del Giudice.97
So, where does this leave us? As Levy and Kelly point out, it is possible that individuals’ biological sex causes them to react differently to harsh and unpredictable environments, and these reactions can in turn influence the development of their attachment style and consequently their reaction to jealousy. As we discussed in Chapter 3, attachment styles are related to life history strategy. Those growing up in harsh and unpredictable environments tend to become insecurely attached, whereas those growing up in stable environments tend to become securely attached. Perhaps males and females react to harsh environments in different ways, influencing how their attachment style is expressed. Only further research will be able to test these ideas.
This all sounds complex, but that’s just our point. Biological sex differences can be explained in a number of ways and can sometimes mask even more fascinating and specific sex differences that are in line with evolutionary theorizing. In our mating intelligence approach, we advocate multiple levels of analysis to get at what is really going on. We wholeheartedly agree with Meston and Buss that “human sexuality is motivated by a complex and multifaceted psychology. Efforts to reduce sexual motivation to small number of variables are doomed to fail.”98
A little-talked-about feature of research on human mating psychology is that sex differences, although real and significant, are only part of the story.
As we discussed in the prior section, we believe that seeing females as long-term strategists—and males as short-term strategists—misses the boat. In fact, given how wonderfully complex and adapted the human mind is, and how central mating is to every aspect of life, it only makes sense that any individual, regardless of sex, will use a variety of mating tactics across his or her lifetime.
Evolutionists often refer to organisms as behavioral strategists, employing different behaviors under different ecological conditions. Without question, humans are not above this basic rule—there is wealth of data suggesting that, regardless of sex, people modify their mating strategy as a function of ecological conditions. And, as we discuss at the end of this chapter, it makes sense to see mating intelligence as the ability to modify mating strategies optimally as a function of the environment.
We’ve already mentioned some important contextual factors that affect mating strategies, such as perception of risk and expectation of pleasure. Many other fascinating context-relevant factors have also been demonstrated as affecting mating strategies. This section offers a sample of some of these.
As we’ve discussed in this chapter and in Chapter 3, a person’s life history strategy has an enormous bearing on his or her mating strategy. Individuals from relatively unstable backgrounds are considered as having a fast life history strategy.99 Individuals from backgrounds that are highly stable and resource rich are more likely to develop slower life history strategies.100 Such individuals are more likely to pursue long-term mating strategies101 and to avoid risk-taking behaviors.102
An important implication of the life history strategy work is that the background of a person’s upbringing and his or her personality (which is steeped in both that background and individual genetic make-up) may well have more of a bearing on the use of long-term versus short-term mating strategies than his or her biological sex. Being a male or a female may actually matter less in determining a person’s mating strategy than that person’s life history strategy—which is largely the result of a person’s past environmental experiences and individual genetic heritage.
Another major ecological variable that affects mating strategies is the prevailing sex ratio. Although we often think of sex ratio as being 50/50, it’s often not. Consider many colleges these days with imbalanced sex ratios. The current first-year class at SUNY New Paltz is 70% female. The current first-year class at Clarkson University, known for its formidable programs in engineering, is 27% female. And if you are a student at one of these schools, it’s a good bet that the prevailing sex ratio at your school matters plenty in terms of optimal mating strategies for you and the thousands of other students there.
Data back this point up. In one of the largest-scale cross-cultural studies ever conducted, David Schmitt103 studied the impact of a nation’s prevailing sex ratio on the average sociosexuality (promiscuity) scores of the country’s inhabitants. Sex ratio matters. In countries with an overabundance of men, male sociosexuality scores go down. Men in such a context cannot afford to be short-term strategists. Women are setting the ground rules—with a home-field advantage. They can pick and choose. In such a context, males have fewer options—and the tendency for males to be short-term strategists diminishes dramatically. Interestingly, under such conditions, women’s scores turn toward promiscuity—under such conditions, they can actually afford to implement short-term strategies without incurring the high costs of male abandonment—remember, males in such a situation are not in a position of power.
When the tables turn and there happens to be an overabundance of women, male sociosexuality scores skyrocket—whereas female scores do not. In such a context, males can have their druthers, and that tends to play out in short-term mating strategies.
Although this research, like any research done by Schmitt, is of extremely high quality, it may only scratch the surface. If nation-level sex ratios are this sensitive to variability in mating strategies, it seems that more localized sex ratios (such as on specific college campuses, which vary quite a bit on this variable) likely have even more dramatic effects on mating strategies. Research on this question should yield fruitful information about the true impact of sex ratios on behavior.
We can’t all get what we want. Sure, we may all want the man or woman who scores high on every single desired attribute, but (a) not everyone can have this person, and (b) honestly, do you really think that perfect mate actually exists? Think again! Because of the realities of the mating market, many of us “satisfice” or end up with a partner that strikes the most reasonable balance of traits we value (see Chapter 4).104 Indeed, research does show that our stated preferences often diverge from what we actually choose.105 Sometimes compromises have to be made.
But how many dates should we go on before we know we’ve found “the one” (to satisfice with)? There is no easy answer. According to the “37% rule,” determined by the “secretary search problem,” first estimate the number of potential mates you are likely to meet in your life, go on a date with the first 37%, assess the best one from that batch, and then marry the next one who comes along who exceeds the “best” one’s value!106 Very romantic, huh? Although this method may be feasible for those who live in a small, rural area, what about city dwellers? A person is likely to meet many more people in New York City than they can keep track of and use to make a statistical calculation!
Does this mean we all settle? Probably not. The truth of the matter is that someone better will always be there, just around the corner (again, unless you live in a really small village). At the end of the day, if you want to be in a committed relationship with someone you love and care for, and you don’t want to always be looking over your shoulder, you will have to convince yourself that this person is the best “fit” for you. Everyone has to believe this—even movie stars (look at the high rate of divorce among them)!
Still, the question of how people decide to stop their search and commit is an important question. Some researchers have suggested that people use their self-perceived mate value as a cue to where they should set their aspiration levels.107
In a sense, mate search is parallel to optimal foraging in wild animals.108 In the process, one scans the environment, calibrates his or her selection criteria, uses past feedback and information to help optimize the current situation, invests time in some areas but doesn’t waste time in others, and so forth. Including self-assessed mate value in such calculations likely helps optimize mate search in humans.
More generally, using one’s own self-assessed mate value in making mating decisions is an important element of mating intelligence. Calibrating decisions based on one’s self-assessed mate value likely affects several kinds of mating decisions, including the following:
• Which mates to pursue for short-term relationships
• Which mates to pursue for long-term relationships
• When to stop searching for a mate and settle on a particular individual
• How much effort to expend in courtship
• How much effort and investment to put into shared investments such as children and materials
A person’s self-assessed mate value is influenced by a number of factors, including physical attractiveness, financial and professional success, and the accumulation of a lifetime of responses from others. A person’s self-perceived mate value can even be influenced by whom else is around.
For instance, Sara Gutierres, Douglas Kenrick, and Jenifer Partch109 found that after men in their sample were exposed to highly socially dominant men, they lowered their rating of their own desirability as a marriage partner, but their self-evaluations had no effect after being exposed to physically attractive men. The reverse occurred for women: women lowered their self-evaluations as a marriage partner after exposure to physically attractive women, but their self-ratings were not affected after being exposed to socially dominant women. The researchers suggest the effects may have been caused by changes in the perceived distribution of physically available or highly dominant people available to members of the opposite sex in one’s local community.
Keep in mind that one’s current self-perceived mate value can be completely off. As Gutierres and colleagues note, the media plays a huge role here:
… we may see in 1 hour dozens of individuals who are more attractive and more successful than any of our ancestors would have seen in a year, or even a lifetime. The results of this program of research suggest that our mental mechanisms may trick us into using such extraordinary individuals as comparison standards for ourselves and our potential mates. (Gutierres et al., 1999, p. 1133)
There are other ways a person’s self-perceived mate value can be highly inaccurate. Consider the girl who grows up with a lot of pimples and is mocked by others and then grows up to become a beauty queen. In her mind, she still may be that 10-year-old awkward girl. Or consider narcissists (whom we discuss at great length in Chapter 8), who have an overly inflated view of their mate value. What matters sometimes is not your actual mate value, but what you truly believe your mate value to be (see Chapter 6) because this influences who you seek out, how quickly you rebound after a rejection, and how you interpret ambiguous information (and quite a lot of the mating game is ambiguous).
Regan110 found the higher that women perceived themselves on various dimensions (e.g., intellect, family orientation), the less willing they were to compromise those traits for a romantic partner as well as a casual sex partner. This effect was not found in men, perhaps because men are more willing to make compromises to increase the likelihood of finding a willing casual sex partner.
Other studies in a real-world context have found similar effects. In their study of speed dating behavior in German adults, Penke and colleagues111 asked participants to rate their own level of physical attractiveness. This variable affected their mating strategies—but especially for women. Women who rated themselves as unattractive were less likely to “go for” males they met in the process who were of relatively high mate value. This effect was considerably diminished for males, suggesting that males in a speed-dating context may have much more of a go-for-broke attitude.
In a more recent study, Back and associates studied the mating dynamics in a speed-dating situation, applying the social relations perspective.112 The social relations perspective takes into account both the individual level and the dyadic level. This allows researchers to investigate different kinds of effects.
Actor effects involve an individual’s typical behavior when interacting with multiple people. For instance, perhaps Fred acts shy on average, when chatting with lots of different people at first acquaintance. Partner effects involve the typical kinds of reactions a person receives from others. In the unfortunate case of Fred, people on average may perceive his shyness as pomposity and may try to avoid him, which of course makes poor Fred even shyer! Finally, relationship effects involve how a person treats a particular person, taking into account that person’s actor and partner effects. Perhaps Fred opens up like a flower when he gets to know someone and feels comfortable with that person. Therefore, that’s why Fred acts like a party animal around his best friend of 30 years, whereas he still has difficulty chatting with strangers.
Adopting this perspective, Mitja Back and associates113 distinguish between individual reciprocity (“Are people who choose many others as potential mates chosen more often by others?”) and dyadic reciprocity (“Is a person who uniquely chooses a specific other person uniquely chosen by that specific person?”). Prior research has shown a rather low (and sometimes even negative) relation between choosiness and popularity.114 In other words, people’s mate choices are rarely reciprocated!
To get to the bottom of this puzzle, Back and colleagues115 set up a speed-dating event in Berlin, in which a total of 190 men and 192 women aged 18 to 54 years went on a number of dates lasting 3-minutes each. The speed-daters then selected whom they’d like to see again and also filled out measures of their personality, including a measure of sociosexuality (which measures how much a person has a short-term mating orientation), extraversion, self-perceived mate value, and shyness. The researchers also had other people judge the facial attractiveness of each speed dater as well as rate the extent to which each speed dater flirted with other dates. What did they find?
Even though people expected their choices to be reciprocated, for the most part they were not. The researchers suggest that this (false) assumption of reciprocity may be a form of self-deception that causes greater displays of confidence and self-assured behavior in an ambiguous social environment.116
Even though choices were not reciprocal, flirting was, on both an individual and dyadic level. In other words, those who were flirty in general tended to receive flirting in return on average, and those who flirted at a specific dating partner tended to receive a flirtatious response from that partner in return. Even so, flirting did not predict the actual outcome of the date. This is not the only study to find this; Karl Grammer and colleagues117 looked at initial heterosexual encounters and found that flirting was only weakly related to actual interest. We apologize to all the flirters out there, but it seems as though flirting doesn’t necessarily indicate interest. People can flirt for a number of reasons: to keep interactions running smoothly, to appear more attractive, or to disguise mating interest.
Looking beyond flirting, how did personality play a role? Although extraverted individuals and men with more of a short-term mating orientation flirted more, the most telling correlation was with self-perceived mate value. Those with a higher self-perceived mate value were choosier and also more popular. Men with a higher self-perceived mate value were more flirtatious and were more likely to receive flirtations in response. Shy men tended to be less choosy, flirted less, and were less popular. Also, consistent with other research presented throughout this book, the effects of personality similarities on mate choices were weak.
In addition to individual differences, the researchers also found a very interesting sex difference. The more popular the man, the more choosy he tended to be, but this relation did not hold for women. This finding seems to be a result of the fact that both self-perceived mate value and physical attractiveness are more strongly related to choosiness and popularity in men than in women. This finding is consistent with another recent study that found that when given the opportunity to choose a mate without any constraints, those with a higher self-reported mate value are much more choosy than those with a lower self-reported mate value.118
Back and colleagues also found that men with a higher self-perceived mate value tended to flirt with others and tended to receive more flirtations, whereas this relation was not found among women. The researchers suggest that this may be due to the possibility that women react more negatively than men to indicators of low choosiness. Future research should further explore the fascinating effects of self-perceived mate value at both the individual and sex-specific levels. Also, dating interactions across the world should be examined: Germany dating rituals may somehow be a quirk of human nature!
Nonetheless, these data speak to an important variable surrounding human mating—one’s own mate value. We admit, getting into the details of measuring and defining mate value is a pretty slippery slope! And rightfully so. One of the points we’ve tried to make in this book is that there are many diverse tools in the arsenal of human mating—from having a square jaw to being effective at self-deprecating humor. That said, Lars Penke and colleagues got it right in determining self-assessed mate value. For years, psychologists have reliably measured different aspects of the self as filtered through self-assessment measures, and at the very least, such measures do provide the researcher with a clear sense of self-perception. So, it’s reasonable to think about how one’s self-assessed mate value likely affects mating decisions.119
As with life history strategy, one’s self-assessed mate value is an important contextual variable that affects mating strategies and decisions—that actually resides within the person. Sometimes, changing your self-perception of mate value regardless of your actual mate value (a term we admit is rather hazy) can have profound effects on your mating outcomes. We discuss the adaptive benefits of self-deception in the next chapter. Just keep in mind that context is sometimes on the inside.
Even with our emphasis in this book on cognitive and dispositional factors, there is no denying that physical features also play an important role in the mating domain.120
One study looked at the role of physical attractiveness in mate selection using the popular website HOTorNOT.com.121 HOTorNOT.com allows members to rate others on how physical attractive (i.e., “hot”) they think they are on a 1 to 10 scale. Each user can also upload his or her own picture for rating by others to rate. There is also an option to engage in the dating component of the site, where members can chat and send messages to others they are interested in. Unsurprisingly, the researchers found that the more physically attractive the person (i.e., highly rated on the website), the more that person preferred dates who also were physically attractive.
Interestingly, one’s own rated level of physical attractiveness did not influence the ratings they gave others. In the researchers’ words:
… the results from analyzing the HOTorNOT.com data imply that whereas less attractive people are willing to accept less attractive others as dating partners, they do not delude themselves into thinking that these less attractive others are, in fact, more physically attractive than they really are. (Lee et al., 2008, p. 675)
The researchers also conducted a study at a speed-dating event in Boston. Before the event, participants filled out a survey in which they indicated their preferences on six dimensions (physical attractiveness, intelligence, sense of humor, kindness, confidence, and extraversion). During the speed-dating event, people went on a series of 4-minute dates where they rated each date on physical attractiveness and how much they were interested in seeing the person again. The researchers found that physically attractive people tended to place more emphasis on the physical attractiveness of others and less emphasis on other traits such as humor. These results are fascinating because they suggest that one’s own level of physical attractiveness may be an important variable that predicts mate choice. At the same time, universally evolved mechanisms are still at play here: people, regardless of their individual levels of physical attractiveness, still agree on others’ levels of physical attractiveness. As the researchers put it:
People seem to adapt to the advantages they experience as a result of their physical looks (much as they adapt to many other situations), achieving roughly similar levels of happiness throughout a wide range of attractiveness levels. (Frederick & Loewenstein, 1999, p. 675)
How do people attain such “hedonic adaptation” (their own phrase)? The researchers suggest they do this by “deluding themselves that what is unattainable is not as great as it looks” and by diverting their attention away from attributes that may seem out of reach to options that may be perceived as attainable.
As we discuss later in this book (see Chapters 6 and 8), self-delusion may be adaptive. Perhaps those who think they can attain mates out of their reach actually change the probability of attaining that mate. As we pointed out in Chapter 4, through continued interaction, one’s perceived levels of physical attractiveness can change quite substantially.122 Lee and colleagues’ study123 involved only very brief encounters. Finally, we don’t know how successful their participants were after they went on their dates. In other words, did their selections actually work out, leading to mating or even relating? We don’t know, but we suspect that the more cues one has available, the better the mating choices they will make. Therefore, because physical attractiveness is the most salient characteristic of a person, it may play a larger role during the initial encounter, whereas many of the mating intelligence components we mention in this book increasingly influence attractiveness as interactions continue.
Simply put: women like men who are liked by women. This makes sense. Sometimes, a potential mate’s value is ambiguous. Under these conditions, the opinions of others can heavily influence how that person is perceived. In social psychology, this is referred to as “social proofing.”124 As François de La Rochefoucauld once put it, “Before we set our hearts too much upon anything, let us first examine how happy those are who already possess it.”125
Evolutionary psychologists call the process by which people choose mates who have been chosen by others mate copying and refer to the strategy as a conformity heuristic. This phenomenon has been documented in other species, such as birds126 and fish.127 In humans, mate copying happens quite frequently128 and may function as a shortcut for learning about a person’s mate value that is not easily attainable on first glance.129
Often, people mistakenly believe that they are making decisions about a person based on the information they gleaned from the situation when in fact they are really basing their decisions on how other people reacted to the situation. Mate copying usually occurs in ambiguous situations when someone is observed to be of high mate value or is told that they have high mate value. Indeed, gossip relating to the sexual domain may just be one of the most widespread behaviors of human nature!
Consider the following set of results relating to the prominence of mate copying in human mating and what factors increase the likelihood that a person will use a conformity heuristic in choosing a mate:
• Both men and women can be influenced by social information about a person when choosing both a short-term and long-term mate.130
• Female mate copying is influenced by the amount of time spent looking at the partner, whereas male mate copying is influenced by the amount of time looking back and forth between the partner and the mate.131
• Women (but not men) show a decrease in interest after watching a date in which the individuals are clearly not interested in each other. Females do show an increase in interest, however, if the individuals look like they are clearly interested in each other.132
• Women tend to be more interested in a man as a potential mate if the man is surrounded by other interested females and/or is clearly committed (i.e., married). These cues hardly influence a potential friend or a potential co-worker.133
• A women’s recommendation can be quite a potent force for other women, sometimes even overriding what women initially consciously think will attract themselves to a man (e.g., looks, age, height, humor).134
• Finding out that a potential partner was rejected by his or her last partner negatively affects participants’ desire to pursue a romantic relationship with that person.135
• Females spend more time looking at a man when he is shown next to an attractive woman compared with when he is shown next to a women lower in attractiveness.136
• Sexually experienced women are less likely to use the conformity heuristic.137 This is presumably because more experienced women have more confidence in what they want in a partner.
• Males tend to show greater mate copying of women whose attractiveness approaches or surpasses their own.138 This effect does not hold for women.
• Men tend to like another man less if he receives a smile from a woman.139 Presumably, this is because in such cases, men tend to feel threatened by such men.
• The conformity heuristic is stronger for already unattractive men (although this is most likely due to a statistical artifact called regression toward the mean, whereby variables that are extreme on first measurement tend to be closer to the “average” when later measured).140
• Those who pay the highest price of the conformity heuristic are undesirable men. So, what’s an undesirable man to do? He can try to create conditions in which he appears in demand by many women, perhaps surrounding himself with a lot of female friends.
An important contextual factor that influences a person’s mating strategy (particularly women) is age. Think college-aged women are more sexual than older ladies? Think again! Judith Easton, Jaime Confer, Cari Goetz, and David Buss141 classified more than 800 women taken from a college and community sample into three age groups based on their probable fertility status: ages 18 to 26 years (high-fertility women), 27 to 45 years (“reproduction-expediting” women), and 46 years and older (women close to or at menopause). The researchers found that those aged 27 to 45 thought more about sex, had more sexual fantasies, and were more willing to engage in sexual intercourse after knowing someone for 1 month, 1 week, or 1 night (a finding that even surprised the researchers!) than both of the other age groups. Although not statistically different from menopausal women, those in the 27- to 45-year-old group also reported a higher intensity of sexual fantasies, fantasized more about their current romantic partner or someone else, and engaged in more sexual intercourse compared with the high-fertility age group. These results held even after controlling for the number of children women already had and whether participants consciously desired having another child.
The researchers argue that women who experience a decline in fertility have evolved a “reproduction expediting adaptation designed to capitalize on their remaining fertility by increasing motivation to engage in sexual activity and increasing frequency of actual sexual behavior.”142 This research is also consistent with the work of Schmitt and colleagues,143 who found that women in their early 30s reported feeling more lustful and seductive and less abstinent than women in other age groups.
Most of the women in Easton and colleagues’ study144 did not have children. Another important factor that may bear on mating strategy (again, particularly for women) is whether the person already has a child or not. Viviana Weekes-Shackelford, Judith Easton, and Emily Stone145 propose that having children from a previous relationship is a major contextual factor that affects a women’s mate preference and strategy. The researchers note the unfortunate finding that the best indicator of child abuse is living with a step-parent,146 a finding that remains even after controlling for potentially related factors such as socioeconomic status. Weekes-Shackelford and colleagues147 argue that because of the potential costs to a women who remarry while having children, women with children from a prior mateship might place greater importance on finding a partner who is willing to invest in the woman and her current or future children. The researchers predict that women with children seeking a mate would place a greater emphasis on the ability and willingness to invest in children, good parenting skills, and compatibility and less emphasis on physical size and strength and attractiveness than a women who does not have children. These predictions await further research but provide interesting hypotheses. Another important contextual factor is a woman’s ovulatory cycle.
This book would be remiss not to touch on the effects of ovulation on human mating strategies. The cat is out of the bag. Based on a flood of recent research on the psychological effects of ovulation, modern scientists are starting to fully rethink the longstanding belief that, unlike in other primates, ovulation in humans is hidden. Human females are rare in the animal world in that they are open to copulation across the ovulatory cycle. Further, although menstruation has obvious physical markers, it has long been thought that ovulation in humans does not.
Evolutionary psychologists who have examined these issues carefully in the past few years have determined that, at the very least, the story has to change a bit. From the evolutionary perspective, being able to detect ovulation would have huge benefits because a female can only become impregnated within a very short window of time each month (with estimates varying between 6 and 72 hours).148 So, it makes sense that ovulation-detection mechanisms would be a part of human mating intelligence.
Primatologists are correct in pointing out that ovulation does not have the same physically conspicuous display in humans as in other primates. In chimpanzees, for instance, ovulating females develop bright-red displays on their rumps that they advertise proudly. Until recently, it was thought that no parallels existed in humans. Turns out, we simply weren’t looking carefully enough. And it turns out that the outward displays of ovulation in human females are largely behavioral in nature.
Not only is ovulation discernible by males, but it also has significant implications for the behavior of both males and females. Earlier in this chapter, we discussed the relative differences in mating strategy between men and women on average. Looking at ovulatory effects adds a bit more nuance to that idea.
Consider a recent study in the city of Vannes in France.149 In this study, 506 women between the ages of 18 and 25 years who were walking alone were approached at random in the pedestrian zone by a 20-year-old “hot” guy and told:
Hello, My name’s Antoine. I just want to say that I think you’re really pretty. I have to go to work this afternoon, and I was wondering if you would give me your phone number. I’ll phone you later and we can have a drink together someplace.
The man, who was a part of the research study as a confederate, waited 10 seconds, then gazed and smiled at the participant. Each participant was then debriefed by another experimenter and given a questionnaire, which asked the number of days since the onset of her most recent menses.
The researchers found an ovulatory cycle effect: young women in their fertile phase (and therefore with a higher probability of bearing a child) agreed more favorably to the request than women in their luteal phase or in their menstrual phase.
Interestingly, this effect was only found with women who were not taking birth control pills. The researchers raise the possibility that pill users may be more sexually experienced, which could have led them to view the confederate as less attractive than those taking the pill. In support of this idea, Hess, Brody, Van Der Schalk, and Fischer150 found that more sexually active women considered men who were strangers as less facially attractive than did women who were less sexually experienced. Nonetheless, this study shows how women’s mating strategies are highly contextual, not just in terms of outside influences but also in regard to internal biological changes (see Chapter 2 for ovulatory cycle effects on perceptions of humor and intelligence).
Other effects of ovulation in females include the following:
• More female-initiated sex with partners
• A relatively strong preference for traditionally masculine partners (and a preference for features that indicate a good marriage partner as they move away from their high-fertility window)
• A higher likelihood of sexual infidelity
• A tendency to be more likely to touch males in casual social situations
• A tendency to be attracted to the scent of relatively symmetrical males
• A tendency to be attracted to relatively creative males
• A tendency to take more risks
• A tendency to be interested in erotic movies
• A tendency to wear relatively skimpy clothing
• A tendency to dance relatively dynamically
• A tendency for different body parts, including breasts, to be more symmetrical
And more.151
The recent research on this topic strongly supports the assertion that the ovulatory cycle has a substantial effect on the behavior of females. Ovulation in humans is observable—you just have to know what you’re looking for.
These effects have significant and measureable outcomes on male behavior, such as the following:
• Males give bigger tips to female strippers who are ovulating.152
• Males find the voices of ovulating females relatively attractive.153
• Males find the scent of ovulating females relatively attractive.154
• Males report finding ovulating females as physically attractive compared with photos of the same women when not ovulating.155
And more.
Human mating is not static. A woman’s ovulatory cycle is in a state of constant change—and the mating psychology and physiology of both females and males seem to take this important contextual factor into account. Human mating strategies depend importantly on the ovulatory cycle.
A common issue people raise regarding evolutionary psychology pertains to the presence of homosexuality. If the human mind and resultant behavioral patterns evolved to facilitate reproduction of an individual’s own genes, how on earth does something like homosexual behavior—which is decidedly not procreative—come about? Although we agree that this is a big question worth extensive discussion and scientific inquiry, we think that people who see this as an issue that ameliorates evolutionary theory are overstating things.
Yes, homosexuality exists—and it exists in varying degrees across all cultures that have been studied.156 Although exclusive homosexuality is more common among males than females,157 exclusive homosexuality does exist across the sexes in varying degrees—and bisexuality exists, too.
Can we conceptualize homosexual behavioral patterns as mating strategies? And, if so, does it make sense to discuss the evolutionary function and origins of such patterns?
We admit, this book is primarily about heterosexual behavior—and we’re not unique—many treatises of mating and relationship behavior share this focus.158 Nonetheless, homosexual behavior is clearly a form of mating behavior—and the widespread prevalence of homosexuality necessitates that evolutionists pay attention to this important human phenomenon.
To this point, theories that try to explain homosexuality within the confines of evolutionary theory have had limited success. Some theories focus on kin-selection-based explanations of homosexuality, suggesting that homosexuals divert a high proportion of parenting behavior to the offspring of genetic relatives, thereby facilitating their genetic lineage because these genes exist in the bodies of nieces and nephews.159 Alternatively, homosexual tendencies may come about as an artifact of the relatively complex functioning of the nervous system, which leads to many kinds of nonadaptive outcomes (from an evolutionary perspective), simply as a function of its complexity.160
There also may be good reason to scientifically discriminate between male and female homoerotic behavior. When asked about their preferences in group-sex situations, heterosexual males reported that they are more likely to prefer having no other males involved, whereas heterosexual females showed an equal preference for including males or females.161 These data suggest that homoerotic tendencies may well be sex differentiated, and that females may be naturally more bisexual than males. This fact may result from the highly polygamous nature of ancestral mating systems, which often included harem-like situations. Females under ancestral conditions who were included in harems of dominant males were likely considered lucky in terms of mating success. Further, given the nature of the harem situation, coupled with males’ desire for multiple females, females may have become comfortable with group-sex situations that included multiple females. On the other hand, heterosexual males were in a very different situation—and monopolizing the females in a harem for themselves would have had clear fitness benefits. This account may explain why heterosexual women are more likely to show bisexual tendencies than heterosexual men.
In any event, homosexuality is clearly a significant part of human relationships and behavior and clearly warrants more extensive study. Future research on the nature of mating intelligence and mating psychology more generally on this topic should bear many fruits as scholars work to better understand this highly valued aspect of humanity.
Is sexual coercion an evolved mating strategy? This question may well be one of the most controversial questions in all of evolutionary psychology. The issues involved ultimately get to the issue of whether rape is an adaptation—and, if so, if there is something natural about rape. You don’t have to think too hard to see how contentious this topic is. Right off the bat, we want to note that no research, no matter what it shows, should condone rape. We agree with Buss and Schmitt when they say:
It should go without saying that rape is illegal, immoral, and terribly destructive to women, and should in no way be condoned, whatever the ultimate causes turn out to be. (Buss & Schmitt, 2011)
With this important point out of the way, there has been some research on this front. In a provocative book on this topic, A Natural History of Rape: Biological Bases of Sexual Coercion, Craig Palmer and Randy Thornhill162 argue that rape is part of a conditional mating strategy—utilized as something of a last resort after alternative strategies fail. Male scorpionflies try to obtain mates by one of three strategies.163 First, they try to carve out a nice territory on a fresh carcass (“Look, my pad’s got a water view and it’s near town!”). If that doesn’t work, they dance in front of the females—showing off their symmetrical bodies. Well, this second strategy really only works if they have symmetrical bodies! A final (and least successful) strategy is used as a last resort—and it is essentially forced copulation.
Are humans like scorpionflies? Do males resort to forms of sexual coercion as a result of the failure of other mating strategies? Is, then, sexual coercion a form of a mating strategy?
This question is a hot topic among evolutionary psychologists—and we believe that it is not directly relevant to the primary goals of this book. But we will say that there are a few broad schools of thought within the evolutionary literature. The idea of forms of sexual coercion as an adaptation has been studied extensively—with data sets that speak to this idea.164
Importantly, all mating occurs in a social context, including a broader community. Wilson and colleagues165 argue that if we’re thinking about rape from an evolutionary perspective, we should focus on how such an act affects the whole community. If there’s a known rapist in the community, this adversely affects everyone. Being a rapist is not so great for one’s reputation. Although a single act of rape may have fitness-enhancing consequences in the short-term, it is likely to have severely negative consequences in the medium- and long-term. Being beaten up or killed by the male kin of a rape victim is not very good for passing on genes. Getting labeled as a rapist in a small community is extremely detrimental for developing strong alliances and social networks. The long-term fitness consequences of acts of sexual coercion are dramatic and negative within normal human communities.
With these ideas in mind, a current research project being conducted in the SUNY New Paltz Evolutionary Psychology Lab seeks to address the question of whether people have specialized abilities to detect convicted rapists. Are people able to discriminate a set of rapists from a set of other convicted (non-rapist) criminals by looking at a series of mug shots? Are women better at this task than are men? Does scoring high on a measure of mating intelligence give people an edge at this task? SUNY New Paltz graduate student Mary Finn is currently leading a project on precisely these questions—looking at how well people can accurately detect whether someone is a rapist.
Something that everyone can agree on is that rape is a very serious problem, one that requires multiple perspectives to fully understand. Griet Vandermassen166 notes that evolutionary scientists and feminists have been needlessly antagonistic. She criticizes both for not being completely open to each other’s scholarly contributions. We believe that multiple perspectives are necessary to come to a deeper understanding of the disturbing phenomenon of rape, including sexual motivations, such as anger, hostility, and hatred toward women, and the role of psychopathy in sexual coercion (see Chapter 8). As Buss and Schmitt167 note, “scientists from all theoretical perspectives have a responsibility to uncover the actual underlying causes of rape, even if they turn out to be unpalatable or repugnant.”
Regardless of whether sexually coercive acts represent evolutionary adaptations per se, mating intelligence may well hold a key to determining who might be most likely to commit such acts. The ability to detect such individuals may well be an important adaptation that is part of human mating intelligence.
By this point, it is clear that there is not a single mating strategy in humans. Although we are products of organic evolutionary forces, ultimately and largely shaped to increase genetic fitness of our own genetic lineages, the “mate as much as possible” strategy is, actually, very ineffective for pretty much anyone. Optimal mating strategies in humans have been shaped across thousands of generations of human evolution—and they are, importantly, complex and designed to take into account several important environmental and biological factors that surround human mating (e.g., prevailing sex ratio, one’s own life history strategy, one’s biological sex).
Human mating intelligence is the set of cognitive abilities that underlie mating psychology. Among the mating mechanisms that make up the core of mating intelligence, the ability to calibrate these mechanisms when implementing mating strategies is crucial. Someone with high mating intelligence will modify behavioral strategies as a function of the prevailing ecology. A male with high mating intelligence in an environment flooded with other males would likely utilize long-term mating tactics. He might underscore his kindness. He might advertise himself as fond of children and willing to take time to attend to them. A male in this same situation who is low in mating intelligence might not realize that it’s never great to be a jerk—but it’s particularly bad to be a jerk in this female-depleted scenario.
As another example, a woman high in mating intelligence might be savvier about ovulation effects than other women. She may realize when she’s with her partner that even though she’s not at the time of month when she’s all fired up, so to speak, this is an effect of this naturally changing cycle. She may allow her cycle to affect her relationship less than if she were not as savvy about such mating-relevant effects of the ovulatory cycle.
For anyone, modifying behaviors as a function of context is often an adaptive process. This is likely especially true when it comes to the mating domain. As we will argue later (see Chapter 9) and throughout this book, we believe that mating intelligence can be increased. We believe that learning about the many variables that affect human mating psychology is a key to this process. Understanding the nature of the human mating strategies and variables that affect them, as described in this chapter—as well as in the broader literature on mating psychology—can have significant and positive effects on the mating lives of modern adults.