One of the leading modern theoreticians of evolutionism, Maybard Smith, while analyzing the reasons behind sexual selection (Smith, 1978), showed that females can be either coy or fast in their sexual choices, while males in turn may adopt the strategy of either the faithful or the philanderer (Dawkins, 1989, p. 151). A society in which all the females are coy and all the males are faithful is a perfect society of exemplary spouses and partners. However, statistics reveal that our society is far from such an ideal.

Infidelity has made its way into our customs and everyday life, inspiring literature, film and theatre. One can analyze infidelity from either the biological or cultural point of view. To put it differently: sexual strategies are often seen as behaviors stemming from human nature, and therefore considered through the prism of biology and human genetics. On the other hand, our sexual choices are constructed and conditioned, mostly towards gender roles, by the hierarchic order of norms and values acquired in the process of socialization.

Each current is based on different explanations regarding the causes and consequences of infidelity. For the purpose of this paper, infidelity has been analyzed from the perspective of sociobiology and sociology of emotions, while gender constitutes the axis of analysis. The main objective of this paper is an attempt to specify whether infidelity results from the biological factor or rather from socio-cultural conditioning.


Ritualistic sexual orgies, wife swapping, or satisfying one’s sexual needs outside of marriage have not always been considered negative behaviors. According to Helen Fisher, in many traditional societies the concept of adultery and its moral evaluation is culturally conditioned. For instance, wife-swapping is considered a sign of hospitality among Eskimos (Fisher, 1994, pp. 86–89). Explicit adultery was also sanctioned with the jus primae noctis. In medieval Europe, by virtue of the right of the first night, a feudal lord had the right to deflower his vassal’s newlywed bride (Fischer, 1994, pp. 86–89). Maintaining extramarital relations with the consent of the spouse can also be encountered in present times. Contrary to common belief, polyamory, a relationship involving more than two people, is becoming increasingly popular (Anapol, 2013, p. 21). The motives behind these relationships are diverse and range from economic to hedonistic. Nevertheless, such cases can be classified neither as infidelity, adultery, nor marital unfaithfulness.

What seems essential, therefore, is to define the concept in question. Infidelity is a phenomenon much broader than adultery and marital unfaithfulness. According to Bogusław Sygit, adultery can be defines as an “act of marital infidelity undertaken in order to engage in sexual intercourse and therefore achieve sexual satisfaction by persons of different sexes, of whom at least one remains in a legitimate marital relationship; the extramarital sexual intercourse is conducted consciously and willingly, regardless of whether the spouse is aware of it and consents to this kind of behavior” (Sygit, 1992, p. 23). Such a definition seems too narrow, as it is limited only to physical contacts by heteronormative, married individuals.

In this paper, infidelity is defined as a breach of partner’s trust in a relationship, through undertaking of sexual contacts with the third party. Hence, classification of an act as infidelity does not depend on the formal context or sexual orientation of the partners. In this sense, infidelity is associated with lies, serious fraud and unfaithfulness towards an intimate partner. Quoting Wojciech Wypler’s definition: “Infidelity constitutes a breach of trust and the explicit rules governing a relationship between two people” (Wypler, 2016, p. 11). To put it differently: infidelity takes place when a person, despite being in a relationship, initiates sexual or intimate relations with another. For the purpose of this analysis, the paper ignores a problem of emotional infidelity, related to inappropriate behavior towards the partner in a relationship. This is not to deny that such behaviors as flirt or online relationships of ambiguous character might also constitute a breach of trust, but they are not defined as infidelity because they do not involve direct sexual relations with another person.

Cultural research on infidelity and affairs shows that the phenomenon is common in all known societies, but also that the approaches towards infidelity vary—at least in the Western culture. The differences lie not in the moral assessment of such behavior, because it has always been judged negatively, and those who yield to a fleeting passion and weakness have always met grave consequences (Fisher, 1994; Mead, 1986). The difference lies in the approach to infidelity through the prism of gender.

As shown by data, both sexes have always initiated, and still initiate, extramarital affairs. Statistics do not leave any doubt on that matter. As pointed out by Bogdan Wojciszke, “infidelity is the most frequent cause of relationship breakdown” (Wojciszke, 2010, p. 301). According to the data of the Central Statistical Office of Poland (GUS, 2018), over 65,000 married couples divorced in 2017, the sole reason for 3750 of the divorces being marital infidelity. In 33.5% of those cases the husband was the unfaithful party. Wife was guilty of infidelity in 18% of cases, both spouses were guilty in 2.5% of cases, without guilty was in 46% of cases (GUS, 2018). Survey data confirms these tendencies. Nearly 50% of adult Poles know somebody who flirts with a person in a long-term relationship or flirts with another person while in a relationship. Almost two-fifths of the respondents (38%) admits that among their circle of friends there are individuals who go a step further in such relationships – towards physical contacts. One in ten respondents admits to having been physically unfaithful towards their partner (CBOS, 2011a, pp. 2–3). According to research conducted by the Centre of Social Prevention, in 2016, 46% of men and 32% of women admitted to marital infidelity. In case of men, acts of infidelity were mostly single incidents, while women more often engaged in long-term affairs (CSP, 2016, p. 6).

Despite both religious and moral commandments condemning infidelity and attempts at restraining sexuality to procreation within marriage, no sanction in any culture has ever succeeded in restraining men and women from marital infidelity (Seidman, 2012, p. 155; Fisher, 1994, pp. 92–93). Over the centuries, nearly everyone has succumbed to it: women and men, believers and non-believers, happily and unhappily married couples, singles, homosexual and heteronormative individuals. Until recently, unfaithful spouses were burned on the stake, buried alive or “merely” mutilated (Fischer, 1994; Sygit, 1992). At present, infidelity provokes equally extreme and dangerous emotions and acts. Nevertheless, people have always cheated on each other, and still do. Hence the question is—why is that the case?

Sociobiological Correlates of Infidelity

From the point of view of Darwinism, the need for sexual diversity is to blame above all other factors for infidelity. According to sociobiology, infidelity is a desired behavior from the genetic point of view, as it allows maximization of the number of children and increases genetic diversity of offspring, which makes the chances of their survival in changing conditions higher. Male infidelity is associated, therefore, with achieving reproductive success: “the male will gain more if he will have the chance to impregnate an extra female, despite the risk of losing the part of the overall adaptive value which he had invested in the offspring of his first partner.” (Wilson, 2016, p. 182). In case of women, the situation is reversed: “Quite the opposite for the female: she will benefit, having secured herself permanent help of the male, despite exposing him to potential genetic costs by drawing him away from other partners” (Wilson, 2016, p. 182).

According to Robert Trivers’ theory of parental investment, the woman will promote behaviors which will increase the chances of her offspring’s survival, such as caregiving and sacrifice. The male, in turn, will measure his own reproductive success with the number of surviving offspring (Wilson, 2016, p. 181). As a result, the female partner will be interested in the “quality” of caretaking which is associated with a huge amount of time and energy she has to sacrifice for her offspring. The man, on the other hand, is interested in the “quantity” of offspring which he is able to produce. In the situation when the woman has a limited range of possibilities regarding reproduction, as “each new embryo is endowed with adequate food by the mother in each case. This therefore places a limit on the number of children a female can have” (Dawkins, 1989, p. 183), it is in the man’s interest to impregnate the highest number of partners as „the number of children a male can have is virtually unlimited.” (Dawkins, 1989, p. 183).

Does this imply that women do not experience the need for sexual diversity? As research shows, both sexes engage in extra-marital sexual contacts to the same extent—although men admit to the fact more willingly, while women tend to hide it more often (CBOS, 2011b). Furthermore, women’s motivation for such contacts are different than mens’s. According to evolutionists, sexual diversity provides women and their offspring with extra means of support, such as “supplementary subsistence ultimately enabling her young to disproportionately survive” (Fisher, 2016, p. 101) and better protection and support (Fisher, 1994, p. 145). Furthermore, in a situation when the father of the child dies, or when he is unable to support his family, the woman could count on the help of another man—the lover (Fisher, 1994, p. 101). In the past, therefore, woman’s infidelity performed an adaptive function. Evolutionary psychologists assume that at least part of the features considered attractive by men and women are not culturally conditioned (Meston & Buss, 2009, pp. 9–30).

Sexual desire is a resultant of many constituents, in the case of both men and women. As shown by the research of David Buss and Calvini Meston, one of the most significant factors is the physical attractiveness of a potential partner. The female sexual desire may be reinforced by tall height, appropriate body built (high V coefficient), a musky smell, or a low voice. Furthermore, women are motivated to have sex by their potential partner’s two character traits: sense of humor and self-confidence (Meston & Buss, 2009, p. 60).

However, the need for sexual variety is more evident in case of men. According to sociobiologists, it can be attributed to drives and needs. Outside of relationships men look, first and foremost, for sex without commitment (of diverse quantity, change, variety)—“A male on the other hand can never get enough copulations with as many different females as possible: the word excess has no meaning for a male” (Dawkins, 1989, p. 203). That is why dissatisfaction with the current relationship is not a primary reasons for disloyalty. As research shows, few people looking for lovers in online dating sites consider their marriages to be definitely unhappy (Hakim, 2014, pp. 67–68). That is why infidelity among men is not necessarily an isndication of a desire to end the current relationship (Wypler, 2016, p. 94). Female adultery is more often motivated by dissatisfaction with the present relationship and by falling in love with another person. That is why women’s affairs more often result in readiness to end the current relationship and enter a new one (Wypler, 2016, p. 94). As Richard Dawkins puts it: “one of the most desirable qualities a male can have in the eyes of a female is, quite simply, sexual attractiveness itself” (Dawkins, 1989, p. 198), which will provide a woman with good genes for her offspring and guarantee numerous grandchildren.

Cultural Correlates of Infidelity

Ulrick Beck and Elisabeth Beck-Gernsheim, having analyzed different types of sexual behaviors among men and women, propose a solution which centers around the cultural differences regarding sexuality and love. In their opinion, the development of a relationship between two sexes, starting with the first meeting and finishing with the sexual intercourse, proceeds according to an invisible protocol, socially pre-defined, of which the individual is usually completely unaware (Beck & Beck-Gernsheim, 2013, p. 87). Not biology, but culture and the process of socialization, especially socialization towards gender roles, plays a decisive role in this process.

Biological explanations of human sexual drives are discarded with the concept of social scripting developed by Edwarda Otto Laumanna and Johna Henry Gagnona. The idea is based on the assumptions that: (1) patterns of sexual behaviors are shaped culturally and locally, which means that the designates of the word “sex” [i.e. sexual intercourse] can vary extremely across cultures; (2) throughout their lives individuals accumulate social scripts of sexual behavior, including those considered deviant in their culture, by means of primary and secondary socialization, e.g. through media; (3) individuals are only “mirrors reflecting social patterns of sexual behaviors, although they can modify them, adapting social patterns individually” (Szlendak, 2011a, p. 219).

It seems justified to analyze the motives behind infidelity, as well as the social functioning of men and women in the context of infidelity, from the perspective of gender. The concept of socio-cultural gender, as noted by Anna Titkow, reveals the meaning and spectrum of differences between women and men, which constitute their status and the rules defining the relationships among them in a given culture. It allows for a closer look at their “struggle” and the cognitive dissonances which they have to deal with (Titkow, 2011, p. 32). From this point of view, if one wants to address the question of the motives behind infidelity in a given society, they should trace the cultural determinants of femininity and masculinity, the social attitudes towards sexuality, as well as the entire set of relationships between the private life and the social structure (Szlendak, 2002, p. 140).

Why are we unfaithful? Of course, we can agree with the common stereotype stating that “men want only sex, while women want love.” Still, one might ask if it is actually true and whether it entails that women do not want sex. Nowadays, both women and men seek sexual pleasure to the same extent, as they perceive it as a basic component of their lives and relationships (Giddens, 2007, p. 85). When a relationship does not provide satisfaction in this regard, sexual needs will be fulfilled outside of it. The need for sexual fulfillment and pleasure is becoming increasingly important in the context of building a reflexive project of self. Sex bears, for men and women alike, a great promise of intimacy, something which—as Anthony Giddens puts it—touches upon the crucial aspect of the “self”. Nevertheless, considering their different starting points, implications of that fact are different for either sex (Giddens, 2007, p. 98–99). That is why in the case of adultery men and women will act—to quote Arlie Hochschils—in accordance with “gender strategies” (Turner & Stes, 2009, p. 57), so as to alleviate negative emotions triggered by the former. All of that for the sake of exciting experiences.

In consequence, engagement in any kind of sexual activity nowadays is related to the individual pursuit of pleasure. The fact that women and men in the modern world engage in “family oriented” activities originates from their egocentric and hedonistic impulses. According to Tomasz Szlendak, the contemporary times are governed by “the logic of individual autonomy” (Szlendak, 2011a, p. 226). As a result, if we are not able to fulfill our erotic and emotional needs within the family, we get involved in affairs. Men betray more often because they are licensed to do so by the pervasive male supremacy. Male infidelity is socially acceptable. Women betray their partners equally often, although they do not admit it—this results from the social expectations.

Social Consequences of Infidelity Versus Double Moral Standards

Infidelity brings about serious consequences for both sexes. Men risk contracting diseases, and gaining a reputation of a philanderer, not to mention bodily harm if the lover’s permanent partner discovers the affair. Moreover, casual sexual contacts consume time, energy, and financial resources. They also carry the risk of ending the current relationship if disloyalty is revealed. The men, therefore, risk a great deal—although women risk much more. A woman involved in an affair, apart from the possible threats to her health, is labeled a “slut”, Even in modern, liberal society such a labelling is much more unfavorable to a woman than to a man. Furthermore, a woman deprived of physical protection by a long-term partner is subject to aggression and attacks by other men. Casual sexual contacts may also result in the breakdown of the current relationship as well as an unwanted pregnancy (Buss, 2000a, 2000b, pp. 111–14). In general, from the gender perspective, the status of men and women in the context of infidelity is different, women being in a decidedly less advantageous position.

Regardless of whether infidelity is analyzed from the standpoint of biology or culture, in the eyes of the society the party guilty of unfaithfulness will always be the woman who cannot remain faithful and seduces married men. As Richard Dawkins points out, much depends on the behavior adopted by the majority of females: “If there are loose females in the population, prepared to welcome males who have deserted their wives, then it could pay a male to desert his wife, no matter how much he has already invested in her children (Dawkins, 1989, p. 191). Margaret Mead’s anthropological research on love and sexual needs among the tribes of New Guinea, in turn, indicates that casual sexual intercourse among the Arapesh is termed as “seduction”, thus as men wander around the country, crossing paths with strange women, they are the ones who tend to be seduced (Mead, 1986, p. 113).

In case of infidelity, the man is therefore only the side who has accepted an offer put forward by the woman. What is more, men enjoy greater freedom in terms of satisfying their sexual needs outside of marriage, which is undoubtedly connected with the higher social status they have held over the centuries. Double social standards go back as far as biblical times. As reported by Frances Cohen Praver, “King Solomon had 700 wives and 300 concubines. In sharp contrast, if a woman strayed, she was stoned to death” (Praver, 2007, pp. 46–47). The depiction of a woman as a loose being, unable to control her own passions has been both perpetuated and condemned over centuries. “In ancient Assyria, adulterous wives had their noses cut off or were killed at the behest of their husbands” (Praver, 2007, pp. 46–47). A portrayal of women as “sexually voracious temptresses of righteous men” (Praver, 2007, pp. 46–47), has been strengthened by the church of first Christians: just as Eve tempted Adam, so does the woman tempt the man. The Victorian era, which pushed women’s sexual needs into the sphere of mental illness, wreaked even greater havoc on male–female sexual relations. Such attitude led to a situation when women became apathetic and passive, their sexual activities restricted to the procreative function. Yet again, these limitations applied only to women. Indeed, sex in the Victorian era was considered a repugnant act. It is worth noting, however, that the abhorrence applied only to marital sex. While women’s sexual needs were marginalized, the society gave men the license to yield to their instincts without restraint (Fisher, 1994; Praver, 2007; Szlendak, 2011b; Foucault, 2010).

The twentieth century liberated women from the tight corsets of sexual restrictions, although patriarchal social structures have always put men in a privileged position. In Western societies, culture—especially double standards and false ideals—have had a great influence on individual sexuality, labeling men as active and women as passive. In the circle of Euro-American culture, women are considered emotional, affectionate and caring, while carnal passion tends to be attributed to men (Seidman, 2012, p. 160).

According to sociobiologists, the justification for double moral standards lies in the “fear of not being a father” A woman who gives birth to a child is always its mother, while her partner is never sure of his paternity. “[T]he male cannot always be completely sure that his mate’s eggs have been fertilized by his own sperm” (Wilson, 2000, p. 182)—which is meant to explain the husband’s obligation to see to his wife’s marital faithfulness. The fear of not being the father is so strong that the male reacts with “brutal forms of aggression” (Wilson, 2000, p. 184) to the actual or potential unfaithfulness of the wife/partner. As reported by David Buss (2014, p. 114), a large share of murders in all cultures is committed by jealous husbands.

In the context of “still” persisting double moral standards, it is not surprising that women tend to hide their acts of infidelity while men are boastful about the matter (CBOS, 2011a). Women, like their prehistoric grandmothers, do not flaunt their romances for practical reasons. First of all, infidelity performs for them an adaptive function: “As long as prehistoric females were secretive about their extramarital affairs, they could garner extra resources, life insurance, better genes, and more varied DNA” (Fisher 1994, p. 101). Secondly, female infidelity is culturally and socially considered a negative phenomenon. Moving on to a more modern ground: “When an office affair comes to light in the atmosphere of a scandal, it is the woman’s reputation which suffers the most.” (Guiliano, 2014, p. 202).

The assumption that it is in the woman’s monogamous nature to have children while the man’s nature strives for new sensations and experiences forms the basis of belief s regarding dissimilar nature of female and male sexuality (Duch-Krzysztoszek, 1998, pp. 134–135). Richard Dawkins argues that “males should tend to be more promiscuous than females. Since a female produces a limited number of eggs at a relatively slow rate, she has little to gain from having a large number of copulations with different males. A male on the other hand, who can produce millions of sperms every day, has everything to gain from as many promiscuous matings as he can snatch” (Dawkins, 1989, p. 203) For that reason, men are inclined to more licentious sexual behavior than women, who in turn attach greater importance to survival strategies and childrearing—and this tendency is further boosted by cultural factors.


Casual sexual contacts carry a great risk for both sexes. However, as they also bring great benefits, men and women alike decide to engage in affairs. From the point of view of sociobiology, infidelity is inherent in human nature, and it is grounded in biological needs and drives. Men are unfaithful as it is in the interest of their genes to produce the greatest possible number of offspring; furthermore, they have a great need for sexual diversity—thus they will strive to satisfy this need with as many partners as they can attract. Women, on the other hand, show a pragmatic attitude towards extramarital relations. Their goal is not to bear a great number of offspring—on the contrary, an accidental pregnancy is an unwanted phenomenon. By engaging in affairs, women aim to gain extra means of support for themselves and their offspring. Thus, for women, an affair performs adaptive functions.

On the other hand, it is not biology but culture, which also determines our decisions and choices. From that perspective the motive for infidelity is the need for pleasure and proximity which, however, are maintained only at a superficial level during an affair. In short, both women and men commit adultery for purely hedonistic reasons: the only difference are the consequences for both sexes. Men are more privileged in this respect. Both the attitudes towards infidelity and the moral judgement of unfaithful men and women vary due to differing cultural expectations faced by either sex. Men and women have completely different views on the subject of sexual needs, faithfulness, and gender obligations. These differences in perspective continue to be strongly reinforced by the double standards introduced in the Victorian age as well as men’s higher social status.

Nevertheless, biology still remains a significant factor governing our sexual drive. As Richard Dawkins remarks, the surprising diversity of sexual and reproductive strategies may suggest that human lifestyle is culturally, rather than genetically-determined (Dawkins, 1989, p. 204). On the other hand, David Buss points out that infidelity is a universal phenomenon, occurring in different cultures (Buss, 2010b), which seems to undermine the role of cultural conditioning in this context. In other words, if evolutionary sexual urges shape our passions, while culture creates the framework and the norms to express them, we are not able to position clearly the motives behind infidelity—neither in culture, nor biology.