Norman P Li & Yla R Tausczik. Encyclopedia of Human Relationships. Editor: Harry T Reis & Susan Sprecher. 2009. Sage Publication.
Romantic relationships are everywhere—people in all cultures engage in various forms of mating, including short-term, casual sexual relationships on the one hand and committed partnerships and marriage on the other. This entry looks at people’s mate preferences, including the characteristics that people desire in long- and short-term relationships, how selective people are in choosing a mate, and trade-offs individuals make. Some important ways in which men and women are alike and differ are described; these mate preference phenomena are explained from two major theoretical perspectives.
Short-term relationships, including one-night stands, casual sex, and sexual affairs, tend to lack commitment and revolve around sexual or physical relations. Conversely, long-term relationships, including marriage and exclusive, steady relationships, tend to involve commitment and investment between partners, and endure for a while. Although people may sometimes find themselves in relationships that have characteristics of both types, a general division of relationships as either committed, long-term, or casual, short-term is nonetheless useful in characterizing the various nuances of mate preferences, and is used in this entry.
Valued Characteristics in Mates
Mate preference researchers have found distinct patterns in the characteristics that people desire for short- and long-term relationships. To begin with, many characteristics are important to both men and women for both types of relationships, including kindness, intelligence, physical attractiveness, creativity, an exciting personality, sense of humor, and social status. For short-term mates such as one-night stands, casual sex partners, and affair partners, both sexes place particularly high value on physical attractiveness. Specifically, both men and women consider it necessary for short-term partners to have a minimum level of physical attractiveness. Indeed, when given the opportunity to obtain information on a potential short-term partner, people inquire first about the potential mate’s physical attractiveness.
For long-term mates such as marriage partners, mutual attraction and love, dependable character, emotional stability and maturity, pleasing disposition, and education and intelligence were identified as the top five most desired characteristics across three major regions in the United States. Many traits, such as those related to kindness and intelligence, tend to be equally valued by men and women and may be important in demonstrating parenting skills, fidelity, trustworthiness, generosity, and ability to maintain a relationship. Such characteristics tend to be equally valued across cultures and generations. However, some preferences are more prevalent in certain cultures. For instance, when David Buss and colleagues compared 29 cultures from different parts of the world, they found that physical attractiveness was more highly valued in cultures with higher levels of parasites. In addition, some characteristics change over time. For example, in an analysis of more than 50 years of studies on mate preferences in the United States, researchers observed an increase in the importance of love and mutual attraction.
The sexes tend to differ on their preferences for physical attractiveness and social status in a longterm mate. Specifically, men value physical attractiveness more than women do and women value social status (and earning potential) more than men do. These sex differences in preference for social status and physical attractiveness have been studied extensively and have been found across age groups and ethnicities in the United States, across several decades, and across numerous countries around the world.
In particular, men prioritize finding a minimum level of physical attractiveness in long-term mates, whereas women prioritize obtaining a minimum level of social status in their partners. That is, although people would ideally like to have well-rounded mates who are great looking, smart, successful, funny, talented, kind, and virtuous, men want someone who is at least minimally physically attractive and women want a partner who has at least a minimal level of social status.
Explaining Sex Differences in Valued Characteristics
The priorities that men and women place on physical attractiveness and women place on social status can be explained by two major perspectives: sociocultural and evolutionary. Sociocultural theories look to social norms (what is appropriate for people to do in social situations) and the influence of larger groups, including family, religion, and society. From a sociocultural perspective, women in most societies have less access to status, power, and economic resources than men do. To gain stable access to economic resources and achieve upward mobility, women need to select marriage partners who have status and income potential. Men, on the other hand, are in the economic power seat, and thus are free to pursue what society deems as pleasurable, such as a long-term mate’s physical attributes. However, if the intended mating duration is short-term, then economic constraints should be less relevant and both sexes should be free to value their mates’ physical attractiveness.
Whereas sociocultural theories revolve around societal constraints, evolutionary theories rely on more distal explanations and consider biological constraints and heredibility. Evolutionary theorists maintain that preferences and behaviors may be heritable, and that the psychologies we have today may have been naturally selected during millions of years. Specifically, psychologies that aided ancestral humans in reproducing more successfully are likely to have been passed down over evolutionary history. Because men and women have different reproductive capacities and constraints, the sexes may have evolved different psychologies relating to mating and reproduction.
Evolutionary theorists note that men vary in their ability to provide resources for offspring. Ancestral men with high social status had good access to resources, whereas ancestral men with low status may have had little or no access to resources. Thus, ancestral women who prioritized having some status in their long-term mates likely secured essential resources for their offspring and outreproduced those who did not and passed this proclivity down through the generations. For short-term mates, resources are less relevant, but a man’s heritable traits, including his physical appearance and qualities implied by his appearance, may be passed on to any resultant offspring. Thus, evolutionary psychological theories suggest that women may value physical attractiveness in short-term mates for heritable benefits. This point is elaborated further later.
Men’s preference for physical attractiveness may be related to an important constraint in female reproductive capacity. Whereas men’s fertility tends to decline slowly over their life spans, women are most fertile in their 20s and decrease in their ability to have children after age 30, until hitting menopause by age 50. Because of this reproductive constraint, ancestral men who were attracted to the most fertile women—more specifically, physical features belonging to the most fertile women—would have outreproduced men who were not. Consequently, attraction toward fertility-related features would have become more prevalent over generations.
Physical Attraction: A Closer Look
The qualities that people list as important in choosing a mate can be further studied to uncover the detailed nature of preferences. Research on what people find physically attractive illuminates the specificity of preferences. Both men and women find physical characteristics that signal good health to be attractive in a mate. Traits such as smooth skin, strong hair, good teeth and gums, and normal gait and movement can provide evidence of good nutrition and healthy development.
Men are additionally attracted to those features in women’s physical appearance that indicate fertility. In particular, men tend to be drawn to secondary sexual characteristics and signals of youth, because female fertility varies with age. These characteristics include full lips, soft and lustrous hair, smooth skin, colorful cheeks, good muscle tone, breasts, buttocks, and a low waist-to-hip ratio (the circumference around the thinnest part of the waist divided by the circumference around the thickest part of the hips).
Among the various features, the waist-to-hip ratio is one that has been studied extensively in recent years. Waist-to-hip ratio is a visual cue that is noticeable from a distance and from behind as well as from the front. Although preferred overall female body size tends to vary over time and by culture, male preferences for a low female waist-to-hip ratio (around 0.7) has been found to be stable across time and across various cultures. Research in this area has found that lower waist-to-hip-ratios are associated with both increased fertility and lower health risks in women. A study done at a fertility clinic found that every 0.1 increase in waist-to-hip ratio is associated with a 30 percent decrease in conception probability.
Conversely, women are physically attracted to male features such as facial masculinity, muscularity, and symmetry that may be indicative of good genes. According to proponents of the good genes theory, a healthy set of genes and immune system allow a person to resist pathogens that can adversely affect developmental stability. In addition to having negative health consequences, individuals who are not able to fend off pathogens during development tend to possess a greater degree of bilateral asymmetry (left-side development deviates from being symmetrical to right-side development). Because testosterone suppresses the immune system, only men who have good immunity are able to maintain high levels of testosterone and remain healthy. Thus, testosterone-related physical features, when present with symmetry, advertise that a man’s genes are resistant to pathogens.
Indeed, research shows that men who are symmetrical tend also to possess testosterone-mediated secondary sexual characteristics such as muscularity, broad shoulders, and facial masculinity, and they are the men that women tend to consider sexually attractive. Compared with asymmetrical men, symmetrical and masculine-looking men start having sex at an earlier age, are more desirable as sexual partners, have more sexual partners, and are more likely to bring their partners to orgasm. In ancestral environments, women who were more physically attracted to symmetrical than to asymmetrical men may have passed on good genes to offspring, who then were more likely to be healthy and survive to reproductive age, and, in the case of male offspring, more likely to be attractive to potential mates.
Which mate preferences a person expresses is influenced by a person’s inclination to seek and accept mates for particular relationships. For instance, men and women tend to be equally careful and selective when entering a potential longterm relationship. Studies have found that when considering minimum requirements for a marriage partner, both sexes have equally high standards. For example, both men and women indicate that they require above-average intelligence in a marriage partner. Where the sexes differ are short-term relationships: men tend to be much more eager than women for sexual opportunities. In a study done on Florida State University’s campus, men and women were approached by an attractive, opposite-sex stranger (actually, a student who was helping to carry out the experiment) who immediately makes an invitation for casual sex. A majority of men—75 percent—said yes, whereas 100 percent of the women said no. Several of the women threatened to call the campus police. In contrast, of the 25 percent of men who declined, many were apologetic and asked to reschedule.
Men are much more willing than women to engage in sexual relations after any length of acquaintance from 1 minute to 5 years. To facilitate sexual relations, men require much less commitment and investment before consenting to sex. Indeed, men report significantly lower standards for short-term relationships, especially for one-night stands. For instance, whereas women’s minimum acceptable intelligence for one-night stands is at the same high level that they require for long-term partners, men indicate that they are willing to accept a one-night stand whose intelligence is far below average (around the 25th percentile).
Explaining Sex Differences in Mate Selectivity
Men’s lower short-term mating thresholds and mate preferences in general can be explained by the two major perspectives. According to a socio-cultural view, societal norms tend to influence men to be more proactive and women to be more passive across many endeavors, including sexual behaviors. Thus, the difference in whether to enter short-term relationships may be the result of gender role differences, whereby men are socialized to be sexually autonomous and women are socialized to be sexually restrained.
An evolutionary perspective suggests an alternative explanation for this sex difference. A key to understanding this perspective is to consider that in an ancestral environment, long before birth control, pregnancy was always a possible outcome of sex. However, women, not men, are physiologically required to provide substantial resources during and after pregnancy for offspring to survive. Thus, uncommitted, casual sexual encounters present much higher potential reproductive costs to women than to men. As such, short-term sexual relationships are reproductively less favorable to women. On average, those ancestral women with a choosier mating psychology that favored longterm relationships, where partners are more likely to stick around and invest in offspring, likely outreproduced those who were less selective and favored having casual sex, where partners are likely to be absent if offspring show up.
Men, on the other hand, are not physiologically constrained by pregnancy and nursing, and can contribute as little as a few sex cells to a casual sex encounter, even if offspring result. As such, male reproductive success can be more readily increased through openness to casual sex than female reproductive success can. Thus, because of the asymmetry in reproductive costs between men and women, men may have evolved to be more open to casual sex and have lower requirements for potential sex partners than women do.
Whereas only women make a potentially substantial reproductive investment in short-term relationships, both sexes tend to invest significantly in the relationship and in raising children in long-term relationships. Thus, according to an evolutionary perspective, both sexes may have evolved to be selective about taking on a long-term partner.
An evolutionary perspective further suggests that in addition to selectivity, men and women may also desire characteristics in mates that indicate a willingness to engage in the preferred relationship type. For instance, when men look for short-term mates they may look for a willingness to engage in casual sex. When men and women look for long-term mates, they look for a willingness to commit.
Tradeoffs in Individuals’ Mate Preferences
Aside from general sex differences, individuals’ own traits affect the type of relationships they pursue and, consequently, the preferences they have in mates. Although women tend to prioritize physical attractiveness in short-term mates and social status in long-term mates, it would be reproductively ideal for women to find mates who can provide both genetic and material benefits to offspring. However, obtaining both sets of features in one male partner is difficult. Such men tend to be in high demand and are targeted by women who are willing to have casual sexual relationships; thus, these men tend to be less committed to any one partner. As such, research suggests that most women may need to make a strategic tradeoff by selecting long-term partners who are higher in investment potential than sexual attractiveness. However, evolutionary-minded researchers also suggest that it may be adaptive for women to seek primary partners who provide investment while obtaining better genes through extra-pair mating (sex with individuals other than one’s primary partner).
Evidence for this dual-mating hypothesis comes from studies that examine mate preferences throughout a woman’s menstrual cycle. Around the time of ovulation, when pregnancy is most likely, female sexual desire becomes stronger and the frequency of sexual fantasies increases. However, these fantasies are directed not toward primary partners, but toward potential affair partners. This is particularly true if a woman’s primary partner is not physically attractive and lacks indicators of genetic fitness, including strength, symmetry, and social dominance. When women are ovulating, they also more strongly prefer masculine faces and symmetrical features in men, and the scent of symmetrical men, compared with when they are not ovulating. Indeed, men who report being chosen for sexual affairs tend also to have symmetrical measurements. Furthermore, self-report research conducted in the United Kingdom indicates that women who are in a steady relationship tend to have sex with their primary partner evenly across the ovulatory cycle. However, if partnered women have sexual affairs, they are more likely to do so around the time of ovulation. A strategic trade-off that men face involves the allocation of effort to mating versus parenting. The resolution of these trade-offs depends on cues from the environment. When men possess indicators of good genes and are sexually attractive to women, they tend to allocate more effort to mating. When men do not have the attributes that make them sexually attractive or otherwise face limited sexual opportunities, they tend to invest more heavily in a single mate’s children. For example, African tribal evidence shows that men of high status have more wives and spend less time on parenting than do men of low status. Thus, men’s access to short-term mates is a primary factor in determining the type of relationship that men prefer, which in turn influences what characteristics they value in a mate.