Perhaps no adaptive domain is more central to re-production than mating. Those in our evolutionarypast who failed to mate failed to become ancestors.Modern humans are all descendants of a long andunbroken line of ancestors who succeeded in thecomplex and sometimes circuitous tasks involved inmating. As their descendants, modern humans haveinherited the adaptations that led to the success oftheir ancestors. Successful mating requires solutions of a num-ber of formidable adaptive problems. These includ-ing selecting a fertile mate, out-competing intrasex-ual rivals in attracting a mate, fending off attemptsto poach one’s mate, preventing the mate from de-fecting, and engaging in all of the necessarily sexu-al and social behaviors required for successful con-ception to take place. As a consequence of the num-ber and complexity of mating problems humanshave recurrently faced over the long expanse of hu-man evolutionary history, it is reasonable to antici-pate that humans have evolved a large and complexarray of adaptations specifically dedicated to thetask of mating.Nowhere do people have an equal desire to matewith all people. Everywhere, some people are pre-ferred as mates, others shunned. Desires are centralto all facets of mating. They determine who we areattracted to, and who is attracted to us. They influ-ence which attraction tactics will be successful(those that fulfill desires) and which attraction tac-tics will fail (those that violate desires). Successfulmate retention tactics involve continuing to provideresources that fulfill the desires of a mate. Failure tofulfill these desires causes breakup and divorce. Atevery step of the mating process, from mate selec-tion to mate expulsion, desires determine theground rules. Sexual Selection and Parental InvestmentAlthough Charles Darwin (1859) recognized thatsurvival was central to the evolutionary process,many natural phenomena he observed seemed tobaffling on the theory of »survival selection.« Henoticed phenomena such as the brilliant plumage ofpeacocks, the flamboyant feathers of cardinals, andthe enormous antlers of deer. How could thesemetabolically costly structures possibly have evol-ved? Many seemed like open lures to predators, andhence detrimental to survival. Darwin also noticedthat males and females of many species appeared tobe different in size and shape. Male elephant seals,for example, weight roughly 4,000 pounds; femaleelephant seals weigh only 1,000 pounds. Amongbaboons, males are twice the size of females.47Human Mating StrategiesAs descendants of a long line of successful maters, modern humans have inherited themating strategies that led to their forebear’s success. These include long-term mating,short-term mating, and mixed mating strategies. This article presents empirical evi-dence supporting evolution-based hypotheses about the complexities of these matingstrategies, which differ substantially for men and women.Human Mating StrategiesSAMFUNDSØKONOMEN NR. 4 – 2002David M. Buss, Professor, Department of Psychology, University of Texas, Austin
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Among humans, males are 12 percent taller than fe-males, on average. Since both sexes have facedroughly the same survival problems, why wouldthey differ in size and morphology? And what couldaccount for variation on the degree of sexual dimor-phism across species?Darwin’s answer to these empirical puzzles wasthe theory of sexual selection (Darwin, 1858, 1871).The theory of sexual selection dealt with the evolu-tion of characteristics due to reproductive, ratherthan survival, advantage. Darwin described twocomponent processes through which sexual selec-tion could take place. In the first, called intrasexualcompetition, members of one sex (often, but not al-ways, the males) engaged in competitive battleswith each other. Two stags locking horns in combatis a prototypical example of intrasexual competi-tion. The victors in these battles gain preferentialsexual access to females. The losers fail to mate.Whatever qualities lead to success in same-sex con-tests, therefore, are passed down in greater numbers(assuming that these qualities are heritable). What-ever qualities are linked with losing either fail to getpassed down or get passed down in fewer numbers.Evolution, that is change over time, occurs as a re-sult of the differential reproduction of the winnersand losers in same-sex contests.It is important to note that intrasexual competi-tion need not always direct physical combat. Malesin some species compete for position in the statusor dominance hierarchy through non-physicalmeans, and position in the hierarchy can be linkedwith preferential access to mates (e.g., Betzig,1986). Males in other species scramble for access toterritory, and access to territory can be linked topreferential access to mates. The key point is thatwhatever qualities lead to success in intrasexualcompetition are passed on in greater numbers,whether the competition is physical combat, ma-neuvering for position in the hierarchy, or scramblefor access to certain resources. The result is evolu-tion through sexual selection.The second process through which sexual selec-tion occurs is intersexual selection. This process in-volves the preferences of members of one sex formembers of the opposite sex who possess certainqualities. Hypothetically, if all women preferred tomate with men who had red hair, those with red hairwould have a mating advantage. Over time, wewould witness an increase in the frequency of red-headedness in the population. The key point is thatthe desires of one sex for certain qualities in a matecan create evolutionary change – either an increasein the frequency of desired qualities or a decrease inthe frequency of undesired qualities.Darwin’s theory of sexual selection was initiallydesigned to explain the various empirical puzzles hehad observed – things like the brilliant plumage ofpeacocks (preferred by peahens) and the larger sizeof males in some species (explained by the advan-tage that size gives males in intrasexual competi-tion). But many puzzles remained. Darwin observedthat females were often the choosy sex (indeed, hesometimes called the process of intersexual selec-tion »female choice«), but he did not know why. Healso observed that males were often the competitivesex, but he did not know why. Roughly a centurywould pass before evolutionary biologists devised apowerful theory to explain what determines whichsex will compete and which sex will exercisechoice, that is, what drives the operation of the twocomponent processes of sexual selection.Trivers’s (1972) answer to these questions wasthe theory of parental investment. According to thistheory, the sex that invests more in offspring wouldbe more choosy about mates. In species with inter-nal female fertilization, the greater parental invest-ment by females makes them a valuable reproduc-tive resource. Gestating, bearing, and breast feedinga child, for example, are costly endeavors. Elemen-tary economics tells us that those who hold valuableresources do not give them away indiscriminately.Evolution favored women who were highly selec-tive about their mates. Women who were not choo-sy would have suffered lower reproductive success.Those who engaged in careful mate selection, pre-ferring for example a man who would stay around,invest in her, and protect her children, enjoyed re-productive benefits. The more an organism channelseffort into parental investment, according to Trivers,the greater the benefits of exercising careful matechoice. The sex that invests less in offspring, ac-cording to this theory, should be more competitivewith each other for access to the high-investing sex.In summary, the relative investment of the two sex-es drives the operative components of sexual selec-tion, with the high investing sex being selected tobe the most discriminating and the lower investingsex being selected to be the most competitive withmembers of their own sex.48Human Mating StrategiesSAMFUNDSØKONOMEN NR. 4 – 2002
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The Menu of Human Mating StrategiesOne of the intriguing features of human mating isthat it cannot be characterized by a singular strate-gy. One item on the menu is long-term committedmating, often, but not always, characterized by aformal public commitment such as marriage. Inlong-term mating, both sexes typically invest heavi-ly in any resultant offspring. As a consequence, andin accordance with the theory of parental invest-ment, sexual selection has likely fashioned in bothsexes high levels of choosiness or selectivity. Poorlong-term mate choices would have been costly foreither sex, because they would have risked wastingtheir heavy investments.Not all mating, however, lasts a lifetime. Humanmatings can last a few years, a few months, a fewweeks, a few days, or even a few minutes. One endof this temporal continuum may be called short-term mating. This temporal dimension turns out tobe critical to many components of mating, perhapsnone more central than the qualities desired. Fur-thermore, humans display remarkable creativity intheir ability to mix and match mating strategies. Itis not uncommon, for example, for a person to en-gage in one long-term committed mateship withheavy investment in children, while simultaneouslypursuing an extramarital affair, or series of affairs,on the side.Humans, in short, are neither solely monoga-mous, nor solely promiscuous; neither polygynousnor polyandrous. Which items on the menu ofstrategies a particular person chooses is heavily de-pendent on contexts. These include the sex ratio inthe mating pool, a person’s mate value, and evenprevailing cultural norms. These issues are brieflydiscussed later, but first, we must outline the centraldesires of men and women in their pursuit of long-term and short-term mates.Qualities Desired in a Marriage PartnerGiven that women have a large obligatory parentalinvestment to produce children, and hence are pre-dicted to be discriminating in their mate choice, thenext key question is: Discriminating about whichqualities? Potential mates vary in thousands ofways, from physical prowess to speed of hair49Human Mating StrategiesSAMFUNDSØKONOMEN NR. 4 – 2002Figure 1
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growth. Adaptationist thinking provides a guide tohypotheses about the evolution of what womenwant, namely those characteristics that reliably ledto an increase women’s reproductive success. Theseinclude selecting a mate who (1) is able to invest re-sources in her and her children, (2) is willing to in-vest resources in her and her children, (3) is able tophysically protect her and her children, (4) is will-ing to physically protect her and her children, (5)will show good parenting skills, and (6) will be suf-ficiently compatible in goals and values to enablestrategic alignment without inflicting too manycosts on her and her children (Buss, 1994).In a large-scale cross-cultural study, Buss and hiscolleagues (Buss, 1989; Buss et al., 1990) exploredhow much women and men desired each of 32 qual-ities in a potential long-term mate. The study in-volved samples from 37 cultures located on six con-tinents and five islands. The samples included Gu-jarati Indians, Estonians, mainland Chinese, SantaCatarina Brazilians, and South African Zulu. Thetotal sample size was 10,047, with an average of272 from each of the 37 cultures.Cultures varied tremendously in the value placedon some characteristics. The desire for chastity orvirginity (lack of prior sexual intercourse) proved tobe the most cross-culturally variable, as shown inFigure 1. Mainland Chinese placed tremendous val-ue on virginity; Scandinavians typically placed littleimportance on chastity.Many characteristics were universally desired byboth sexes. Worldwide, women and men wantedmates who were intelligent, kind, understanding,dependable, and healthy. Similarly, mutual attrac-tion/love emerged as one of the most valued quali-ties in a spouse worldwide.Despite these cultural variations and universalcommonalities, women and men differed across theglobe on their desire for some qualities. Women,significantly more than men, desired »good finan-cial prospect,« as well as the qualities that lead toeconomic resources, such as ambition and industri-ousness (see Figure 2). Men, significantly morethan women, desired partners who are »good look-ing« and »physically attractive.« Physical appear-ance, as voluminous research has shown, provides a50Human Mating StrategiesSAMFUNDSØKONOMEN NR. 4 – 2002Figure 2
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wealth of cues to a woman’s health and fertility (seeBuss, 1999 for a review).Men universally wanted mates who were youn-ger than themselves, confirming the hypothesis thatmen desire fertility cues (see Figure 3). Evolution-ary models have predicted that what men desire isnot youth per se, but rather features of women thatare associated with reproductive value or fertility.This perspective leads to a counterintuitive predic-tion when it comes to the age preferences of adoles-cent males: teenage males are predicted to preferwomen who are slightly older then they are, con-trary to the typically observed pattern of men desir-ing younger women. This prediction is based on thefact that women slightly older than these teenagedboys have slightly higher fertility than women theirown age or women who are younger (Kenrick,Keefe, Gabrielidis, & Cornelius, 1996). The findings of the Kenrick et al. (1996) studiesconfirmed this counterintuitive prediction. Althoughteenage males were willing to accept dates withwomen who were slightly younger, they foundwomen a few years older to be the »most attrac-tive.« Interestingly, this finding occurs despite thefact that these older women express no interest atall in dating younger men. Taken together, the cu-mulative findings suggest that men’s age prefer-ences exist, at least in large measure, because of thehistorically recurring link between a woman’s ageand her fertility. Although not predicted in advance, it turned outthat women wanted partners who were a few yearsolder than themselves, possibly a cue to greater ma-turity, resources, and willingness to commit.In summary, universal sex differences occurredin precisely those domains predicted to involve sex-linked adaptive problems, notably the selection ofmates who have the ability to invest resources(women prefer more than men) and mates who dis-play cues to youth and beauty, known signals of fer-tility (men prefer more than women). Despite theseuniversal sex differences, most mate preferences51Human Mating StrategiesSAMFUNDSØKONOMEN NR. 4 – 2002Figure 3
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show great similarity between the sexes (e.g., kindand understanding, intelligent, healthy), and thereare also important cultural differences in the desires(e.g., chastity).It is important, of course, to obtain independentconfirmation of these findings from alternativemethods that do not rely on expressed preferences.And indeed, many alternative methods support thevalidity of the methods used to obtain expressedpreferences. A study of actual marriages in 29 dif-ferent cultures, for example, confirmed that men dochoose younger women (Buss, 1989). Grooms wereolder than brides in each one of the 29 cultures, withan average age difference of three years. Further-more, as men get older, if they get divorced and re-marry, they tend to marry women who are increas-ingly younger than they are. The age gap is threeyears at first marriage, five years at second marriage,and eight years at third marriage (Buss, 1994).Studies of the response rates to personals ads al-so confirm the results found with expressed prefer-ences. Women mentioning physical attractivenessand young age as part of their self-description intheir ads receive significantly higher response ratesthan women who are older or who fail to mentionanything about their physical attractiveness. Con-versely, men who mention excellent financial re-sources in their self-descriptions in their ads re-ceived a higher response rate from women than menwho fail to mention this attribute (Baize & Schroed-er, 1995).Finally, studies of the behavioral tactics that menand women use to attract mates, retain mates, andderogate their rivals all correspond closely to theexpressed desires of the opposite sex. Women, forexample, tend to put more effort into appearanceenhancement in mate attraction and mate retention,and when they derogate their rivals they focus onthe rival’s physical flaws (e.g., mentioning that theother woman’s thighs are heavy). Conversely, mentend to display and bestow resources on the womenthey are trying to attract and retain. They tend todenigrate their rivals by impugning the rival’s pro-fessional prospects, such as mentioning that he rivalis lazy, lack ambition, or lacks clear goals in life(see Buss, 1994, for summaries of these studies).When men and women attempt to deceive each oth-er, they do so precisely along the lines of the desiresexpressed by the opposite sex (Tooke & Camire,1991).It is worth noting that, conceptually, we do notexpect a perfect correspondence between expresseddesires and actual mating behavior for the simplereason that people cannot always get what theywant. A person’s own level of desirability, for ex-ample, will limit the ability to translate ideal matepreferences into an actual mating. Most peoplemust settle for someone who is less than what theyideally want. Nonetheless, the available evidence isstrongly convergent from a variety of differentmethods that these fundamental desires differ formen and women and affect actual mating behaviorin precisely the ways predicted.Desires in Short-Term MatingTrivers’s (1972) theory of parental investment pro-vides a powerful basis for predicting sex differencesin the pursuit of short-term matings. Men, morethan women, are predicted to have evolved a greaterdesire for casual sex. The same act of sex that caus-es a woman to invest nine months in pregnancy ob-ligates the man to little or no investment. Over aone-year period, an ancestral man who managed tohave short-term sex with dozens of women wouldhave caused many pregnancies. An ancestralwoman who had sex with dozens of men in thesame year would produce only a single child. Thereproductive benefits to men of short-term mating,in sum, would have been a direct increase in off-spring production. A married man with two chil-dren, for example, would have increased his repro-ductive success by 50 percent by one short-termcopulation or affair that resulted in conception andbirth.The empirical evidence for a sex difference indesire for short-term mating is extensive, supportedby hundreds of scientific studies. When asked howmany sex partners they would ideally like, menstate that they would like 18 in their lifetime,whereas women average around 4.5, as shown inFigure 4 (Buss & Schmitt, 1993). These large sexdifferences have been replicated using different sta-tistical methods of calculating central tendency(e.g., medians rather than means) on samples di-verse in age (Schmitt et al., in press).Another psychological solution to the problemof gaining sexual access to a variety of partners isto let little time elapse between meeting a desiredfemale and seeking sexual intercourse. The lesstime a man permits to elapse before seeking sexual52Human Mating StrategiesSAMFUNDSØKONOMEN NR. 4 – 2002
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intercourse, the larger the number of women he cansucceed in copulating. In one study that has beenextensively replicated, men and women rated howlikely they would be to consent to sex with some-one they viewed as desirable if they had know theperson for only an hour, a day, a week, a month,and so on. Both men and women say that theywould probably have sex after knowing a desirablepotential mate for five years (see Figure 5). Atevery shorter interval, men exceeded women in thereported likelihood of having sex.A behavioral study confirmed this large sex dif-ference (Clarke & Hatfield, 1989). Men and womenexperimenters approached total strangers on a col-lege campus, and said »Hi, I’ve been noticing youaround campus, and I find you very attractive.«Then they asked one of three questions: Would yougo out on a date with me? Would you go back to myapartment with me? Would you have sex with me?The experimenters recorded the percentage whoagreed to each request, and also any verbal com-ments they made.Of the women approached by the male experi-menters, 50% agreed to go out on a date with him;6% agreed to go back to his apartment; and 0%agreed to have sex. Some women who were askedfor sex were insulted, and some thought is bizarre.Of the men approached by the female experi-menters, 50% agreed to go out on a date, similar tothe women’s responses. However, 69% agreed to goback to her apartment. And 75% agreed to have sexwith her. Of the men who declined the sexual re-quest, some were apologetic, citing a prior commit-ment with parents of a fiancé. These sex differenceshave been replicated in subsequent studies (seeBuss, 2000, for a summary).In summary, is quite apparent that men haveevolved psychological mechanisms dedicated tosolving the complex problems posed by success atshort-term mating. These include a desire for sexualvariety, the tendency to let little time elapse beforeseeking sexual intercourse, and the behavioral will-ingness to consent to sex with strangers. In addi-tion, men appear to lower their standards dramati-cally in the context of short-term mating (Buss &Schmitt, 1993); show a marked decrease in attrac-tion to a sex partner immediately following sexualintercourse, perhaps to facilitate a hasty post-copu-lation departure (Haselton & Buss, 2001); reportexaggerating the depth of their feelings to gain sex-ual access (Buss, 1994); and report that they wouldhave an extramarital affair if they knew that no one53Human Mating StrategiesSAMFUNDSØKONOMEN NR. 4 – 2002Figure 4
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would find out (for reviews of this evidence, seeSchmitt et al., 2001).Women’s Short-Term Mating StrategiesAlthough the empirical evidence is clear that men,far more than women, have a great desire for a vari-ety of sex partners, there is a problem – men couldnever have evolved such a desire in the absence ofwilling women (barring deception or forced inter-course). Indeed, mathematically, the mean numberof sex partners for men and women must be identi-cal, assuming an equal sex ratio in the population.Ever time a man has sex with a woman whom hehas not previously had sex, a woman is simultane-ously having sex with a man with whom she hasnever had sex.Perhaps because the evolutionary logic for menhaving evolved a strong desire for sexual variety isso clear – namely, an increase in direct reproductiveoutput – the evolutionary logic for women havingevolved a short-term mating psychology has beenrelatively neglected. The puzzle is deepened by thefact that short-term mating often carries substantialcosts for women. Women, more than men, riskdamage to their reputations, a lowering of percep-tions of their mate value, and if mated, the possibili-ty of violence at the hands of a jealous boyfriend orhusband. Given these costs, it is unlikely that selec-tion would have forged a female short-term matingpsychology in the absence of substantial benefitsthat outweigh those costs.In an effort to explore what those benefits mightbe, Greiling and Buss (2000) extracted from the lit-erature and formulated a number of hypothesesabout potential benefits that women could obtainfrom short-term mating. These include resource hy-potheses (e.g., immediate resource accrual), genetichypotheses (e.g., producing more genetically di-verse offspring), mate switching hypotheses (e.g.,using a short-term mating as a means to exit a poormateship), mate skill acquisition hypotheses (e.g.,clarifying mate preferences), and mate manipula-tion hypotheses (e.g., deterring a partner’s future in-fidelity). Greiling and Buss (2000) conducted a series offour empirical studies to identify which hypothesesappeared promising and which did not. Althoughlimited in scope, these studies were designed to ex-54Human Mating StrategiesSAMFUNDSØKONOMEN NR. 4 – 2002Figure 5
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amine (1) the perceived likelihood that a womanwould receive particular benefits through a short-term mating; (2) the perceived magnitude of bene-fits if received; (3) the contexts in which women en-gage in short-term mating; and (4) individual differ-ences among women in proclivity to engage in pur-sue short-term matings in their perceptions of bene-fits. Below are reported only the result of short-termextra-pair mating (EPC).The hypotheses that received the most empiricalsupport across studies were those of resource acqui-sition and mate switching. For example, womenjudge it to be highly likely that they will receivejewelry, money, free dinners, or clothing by engag-ing in short-term mating. Furthermore, a criticalcontext if which women consider short-term affairsis when the partner cannot hold down a job. Womenwho actively engage in short-term mating, in con-trast to their more monogamous counterparts, judgethe resource benefits to be »more beneficial.«The hypothesized »mate switching function« ofwomen’s short-term mating would, of course, onlyapply to context in which the short-term mating isan affair or an extra-pair copulation (EPC). Con-texts in which women judge it to be highly likelythat they will have an affair include »feeling thatshe could find someone with whom she is morecompatible than her current partner.« Furthermore,women perceive it to be highly beneficial to discov-er a sexual partner who is interested in making acommitment to them, willing to spend a lot of timewith them, and able to replace her current partner.In summary, mate switching and resource acquisi-tion appear to be two viable contenders for theevolved functions of short-term mating. Further re-search, of course, is needed to test these hypothe-ses, as well as others such as »good genes,« forwhich there is independent evidence (e.g., Ganges-tad & Thornhill, 1997).The existence of already mated women whosometimes engage in EPC’s implies the existence ofa pervasive problem for men – the presence of matepoachers.Mate PoachingMate poaching may be defined as behavior de-signed to lure someone who is already in a romanticrelationship, either temporarily for a brief sexual li-aison or more permanently for a long-term mating.Until recently, practically nothing was known scien-tifically about the phenomenon of mate poaching.According to one recent study (Schmitt & Buss,2001), it mate poaching turns out to be a prevalentphenomenon. Using a relatively mature sample ofAmerican participants, averaging 41 years of age(range = 30 – 65), 60% of the men and 53% of thewomen reported having attempted to poach some-one as a long-term mate who was already in an ex-isting committed relationship. The comparable fig-ures for attempting to attract an already-mated per-son for a short-term sexual liaison were 60% formen and 38% for women.The majority of this sample also reported beingrecipients of mate poaching attempts by otherswhile they were in a committed romantic relation-ship. These figures for the long-term mating contextwere 93% for men and 82% for women. Eighty-seven percent of the men and 94% of the women re-ported being recipients of mate poaching attemptsfor brief sexual matings.Attempted mate poaching is one issue; success-ful mate poaching is another. When asked whetherthey have been successfully lured away from an ex-isting relationship, 67% of the men and 41% of thewomen responded affirmatively for the long-termcontext. And 40% of the men and 31% of thewomen report having been successfully seduced bya mate poacher for a short-term sexual liaison. Sim-ilar findings have been obtained cross-culturally insamples from Israel, Turkey, Greece, Croatia,Slovenia, Poland, Portugal, Germany, France, Eng-land, and Canada (Schmitt, 2001).Jealousy and Mate GuardingThe phenomena of infidelity and mate poachingpose serious adaptive problems. If these phenomenahave recurred over the long course of human evolu-tionary history, and there is no reason to believethat they haven’t, the principle of co-evolution sug-gests that strategies will evolved to defend againstthese problems and the costs they impose. One pos-sible solution involved the evolution of jealousy(Buss, et al., 1992; Daly, Wilson & Weghorst, 1982;Symons, 1979). Jealousy is an emotion that is acti-vated whenever there is a threat to a valued relation-ship (Daly et al., 1982). Threats can come in manyforms, such as the loss of a partner’s sexual, finan-cial, or emotional resources to a rival. Threats cancome from within the relationship from a partnerwho might have the urge to stray, or from outside55Human Mating StrategiesSAMFUNDSØKONOMEN NR. 4 – 2002
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the relationship in the form of mate poachers at-tempting to lure a partner away.Over the past decade, a substantial amount of re-search has been devoted to exploring jealousy as anevolved solution to the problems of infidelity andmate poaching (for a summary, see Buss, 2000).The specifics of the adaptive problems differ formen and women, according to evolutionary theo-rists (Daly, et al., 1982). Because in humans fertil-ization occurs internally within women, men cansuffer a lack of certainty in their paternity. In con-trast, women are always 100% certain that their off-spring are their own. Sexual infidelity, of course, isthe event that can compromise a man’s paternity inoffspring. Although women have never confrontedthe problem of maternity uncertainty, an infidelityby a woman’s mate can be extremely damaging.The woman whose husband is unfaithful risks los-ing his time, resources, and commitments, all ofwhich could get channeled to a rival female and herchildren. For these reasons, evolutionary theoristshave predicted that men, more than women, wouldget upset about signals of sexual infidelity. In con-trast, women, more than men were predicted to getupset about signals of emotional infidelity, sinceemotional involvement is a leading indicator of thediversion of these resources and commitments(Buss et al., 1992).Dozens of empirical studies, using a variety ofmethodologies, have now been conducted to test forthis sex difference (see Buss, 2000, for summaries).In one study, participants were asked to imaginethat their romantic partner had become both sexual-ly and emotionally involved with someone else(Buss et al., 1999). Then they were asked to indi-cate which aspect of the betrayal was more upset-ting. In an American sample, 61% of the men, butonly 13% of the women judged the sexual infidelityaspect of the betrayal to be the most upsetting. Con-versely, only 39% of the men, but 87% of thewomen, judged the emotional attachment to the oth-er person as more upsetting. Similar sex differenceshave been obtained in Korea and Japan (Buss et al.,1999), China (Geary et al., 1995), and Sweden(Wiederman & Kendall, 1999).In summary, men and women differ, as original-ly predicted in advance by evolutionary theorists, inthe weighting given to the events that activate jeal-ousy. Men, more than women, tend to become ex-tremely distressed over signals of sexual infidelity;women more than men tend to become more dis-tressed over signals of emotional infidelity. Ofcourse, both sexes typically get extremely upset byboth forms of infidelity, as they should given thatboth forms threaten key reproductively relevant re-sources. Furthermore, the two forms of infidelityare positively correlated in everyday life – peopletend to become sexually involved with those withwhom they are emotionally involved and vice-ver-sa. Nonetheless, the findings are clear in supportingthe original predictions about the psychological de-sign of jealousy as an evolved defense against infi-delity and the threats posed by mate poachers.Men and women also appear to be threatened bysomewhat different qualities in intrasexual rivals.Specific evolution-based predictions were testing ina cross-cultural study that included Korea, theNetherlands, and the United States (Buss et al.,2000). Korean, Dutch, and American men, morethan corresponding women, reported greater dis-tress when a rival who was interested in their part-ner surpassed them on financial prospects, jobprospects, and physical strength. In contrast, Kore-an, Dutch, and American women report greater dis-tress when a rival surpasses them on facial and bod-ily attractiveness. Although both sexes are equallyjealous overall, the sexes differ in the weightinggiven to sexual versus emotional infidelity as wellas in the qualities of rivals that they find threaten-ing.If jealousy is an evolved emotion, and the empir-ical evidence so far appears to support this proposi-tion, then the next step is to explore the behavioraloutput of this emotion. Two different studies haveexplored »mate retention tactics« of men andwomen, using both married couples and dating cou-ples as participants (Buss, 1988; Buss & Shack-elford, 1997). Mate retention tactics are specific be-haviors designed to ward off rivals or to deter amate from straying. The specific tactics range fromvigilance (e.g., He called her at unexpected times tosee who she was with) to violence (e.g., He hit theguy who made a pass at her). Married men tend to engage in especially vigor-ous mate retention efforts when their spouse inyoung in age and physically attractive. In contrast,women tend to engage in especially vigorous materetention efforts when married to men who havegood jobs, high incomes, and devote a lot of time tostatus striving. In addition, there are sex differences56Human Mating StrategiesSAMFUNDSØKONOMEN NR. 4 – 2002
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in the types of mate retention tactics used. Men,more than women, tend to display resources to theirmate, as well as threaten and commit violence onintrasexual rivals. Women, more than men, tend toenhance their physical appearance as a mate reten-tion strategy, as well as intentionally evoking theirpartner’s jealousy. Intentionally evoking jealousy,for example by flirting with other men and elicitingtheir interest, appears to be a strategy women use toincrease their mate’s perceptions of their desirabili-ty (Buss, 2000).ConclusionsHumans have evolved a complex menu of matingstrategies. These include long-term committed mat-ing, brief sexual encounters, and extramarital af-fairs. Long-term mate preferences are complex, re-flecting desires for many different qualities such askindness, intelligence, mutual attraction, love, de-pendability, and good health. Two universal clustersof sex differences are the desire for youth and beau-ty (men value more than women) and the desire fora mate who has good financial prospects and elevat-ed social status (women value more than men).These profound sex differences have been docu-mented not just in studies of expressed preferences;they have also been confirmed in studies of actualmarriages, responses to personals ads, and tactics ofmate attraction, mate retention, competitor deroga-tion, and intersexual deception.The empirical evidence is strong that men haveevolved a more powerful desire for a variety of sexpartners. The evolutionary logic for this sex differ-ence is clear-cut – men who succeeded in securingsexual access to a variety of women would haveachieved greater reproductive success than menwho did not. Nonetheless, there is a hidden side tofemale sexuality, and some women some of thetime also pursue short-term matings. These musthave been beneficial for women in the currency ofgood genes, increased access to resources, or theability to switch to a superior mate. Nonetheless,women who cuckold their husbands historicallyhave inflicted large reproductive costly on their reg-ular mates. Cuckolded men risk diverting years ordecades of parental resources to a rival’s offspring.The principle of co-evolution predicts that men willhave evolved adaptations designed to defendagainst the diversion of their mate’s sexual and re-productive resources.Jealousy as an emotion has been proposed as onesuch evolved defense mechanism. The empirical ev-idence strongly supports several evolution-basedhypotheses about the psychological design of jeal-ousy. Male jealousy, more than women’s, is en-gaged by signals of sexual infidelity and rivals toexceed them on the qualities that women are knownto want in a mate such as good financial prospects.Women’s jealousy, more than men’s, is activated bysignals of emotional infidelity (and hence potentiallong-term diversion of commitments) as well as byrivals who exceed them on facial and bodily attrac-tiveness.Much more research needs to be conducted onthe complexities of human mating strategies. At thispoint in evolutionary science, however, we havesome of the broad outlines of the fundamentals ofhuman mating strategies and the ways in whichthey are designed differently in men and women.Further research is needed on the context-sensi-tive nature of human mating strategies. Preciselywhich circumstances might cause a person to shiftfrom a long-term mating strategy to a short-termmating strategy and vice-versa? Which circum-stances might trigger an extramarital affair, or con-versely, cause someone to forgo an alluring sexualopportunity? How do the various desires combine,given social contexts and a person’s own level ofdesirability, to form actual mate choices? These andother complexities of human mating are currentlybeing explored by scientists who have grasped thecentrality and importance of human mating to somany different dimensions of social living.ReferencesBaize, H.R., & Schroeder, J.E. (1995). Personality and mateselection in personal ads: Evolutionary preferences in a pub-lic mate selection process. Journal of Social Behavior andPersonality, 10, 517-536.Betzig, L.L. (1986). Despotism and differential reproduction:A Darwinian view of history. Hawthorne, NY: Aldine.Buss, D. M. (1988). From vigilance to violence: Tactics ofmate retention. Ethology and Sociobiology, 9, 291-317.Buss, D.M. (1989). Sex differences in human mate prefer-ences: Evolutionary hypotheses testing in 37 cultures. Behav-ioral and Brain Sciences, 12, 1-49.Buss, D.M. (1994). The evolution of desire: Strategies of hu-man mating. New York: Basic Books.57Human Mating StrategiesSAMFUNDSØKONOMEN NR. 4 – 2002
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Buss, D.M. (1999). Evolutionary psychology: The new sci-ence of the mind. Boston: Allyn & Bacon.Buss, D.M. (2000). The dangerous passion: Why jealousy isas necessary as love and sex. New York: Free Press.Buss, D. M., Abbott, M., Angleitner, A., Biaggio, A., Blanco-Villasenor, A., BruchonSchweitzer, M [& 45 additional au-thors]. (1990). International preferences in selecting mates: Astudy of 37 societies. Journal of Cross Cultural Psychology,21, 5-47.Buss, D.M., Larsen, R.J., & Westen, D. (1996). Sex differ-ences in jealousy: Not gone, not forgotten, and not explainedby alternative hypotheses. Psychological Science, 7, 373-375.Buss, D.M., Larsen, R., Westen, D., & Semmelroth, J. (1992).Sex differences in jealousy: Evolution, physiology, and psy-chology. Psychological Science, 3, 251-255.Buss, D.M., & Schmitt, D.P. (1993). Sexual strategies theory:An evolutionary perspective on human mating. PsychologicalReview, 100, 204-232.Buss, D.M., & Shackelford, T.K. (1997). From vigilance toviolence: Mate retention tactics in married couples. Journalof Personality and Social Psychology, 72, 346-361.Buss, D.M., Shackelford, T.K., Kirkpatrick, L.A., Choe, J.,Hasegawa, M., Hasegawa, T., & Bennett, K. (1999). Jealousyand beliefs about infidelity: Tests of competing hypotheses inthe United States, Korea, and Japan. Personal Relationships,6, 125-150.Buss, D.M., Shackelford, T.K., Choe, J., Buunk, B.P., & Dijk-stra, P. (2000). Distress about mating rivals. Personal Rela-tionships, 7, 235-243.Clarke, R.D., & Hatfield, E. (1989). Gender differences in re-ceptivity to sexual offers. Journal of Psychology and HumanSexuality, 2, 39-55.Daly, M., Wilson, M., & Weghorst, S. J. (1982). Male sexualjealousy. Ethology and Sociobiology, 3, 11-27.Darwin, C. (1859). The origin of the species. London: Mur-ray.Darwin, C. (1871). The descent of man and selection in rela-tion to sex. London: Murray.Gangestad, S.W., & Thornhill, R. (1997). Human sexual se-lection and developmental stability. In J.A. Simpson & D.T.Kenrick (Eds.), Evolutionary social psychology (pp. 169-195). Mahwah, NJ: Erlbaum.Geary, D.C., Rumsey, M., Bow-Thomas, C.C., & Hoard,M.K. (1995). Sexual jealousy as a facultative trait: Evidencefrom the pattern of sex differences in adults from China andthe United States. Ethology and Sociobiology, 16, 355-383.Greiling, H., & Buss, D.M. (2000). Women’s sexual strate-gies: The hidden dimension of extra-pair mating. Personalityand Individual Differences, 28, 929-963.Haselton, M., & Buss, D.M. (in press). The affective shift hy-pothesis: Emotional reactions to first time sexual intercourse.Personal Relationships.Kenrick, D.T., Keefe, R.C., Gabrielidis, C., & Cornelius, J.S.(1996). Adolescents’ age preferences for dating partners: Sup-port for an evolutionary model of life-history strategies. ChildDevelopment, 67, 1499-1511.Schmitt, D.P. (2001). Human mate poaching: Tactics andtemptations for infiltrating existing mateships. Paper present-ed to the Annual Meeting of the Human Behavior and Evolu-tion Society, London, June.Schmitt, D.P., & Buss, D.M. (2001). Human mate poaching:Tactics and temptations for infiltrating existing relationships.Journal of Personality and Social Psychology, 80, 894-917.Schmitt, D. P., Shackelford, T. K., Duntley, J., Tooke, W., &Buss, D. M. (in press). The desire for sexual variety as a toolfor understanding basic human mating strategies. PersonalRelationships.Symons, D. (1979). The evolution of human sexuality. NewYork: Oxford.Tooke, W., & Camire, L. (1991). Patterns of deception in in-tersexual and intrasexual mating strategies. Ethology and So-ciobiology, 12, 345-364.Trivers, R.L. (1972). Parental investment and sexual selec-tion. In B. Campbell (Ed.), Sexual selection and the descentof man: 1871-1971 (pp. 136-179). Chicago: Aldine.Wiederman, M.W., & Kendall, E. (1999). Evolution, gender,and sexual jealousy: Investigation with a sample from Swe-den. Evolution and Human Behavior, 20, 121-128.58Human Mating StrategiesSAMFUNDSØKONOMEN NR. 4 – 2002
