Incidence[ edit ] After the Kinsey Reports came out in the early s, findings suggested that historically and cross-culturally, extramarital sex has been a matter of regulation more than sex before marriage. For example, one study conducted by the University of Washington, Seattle found slightly, or significantly higher rates of infidelity for populations under 35, or older than Rates of infidelity among women are thought to increase with age.
In one study, rates were higher in more recent marriages, compared with previous generations; men were found to be only "somewhat" more likely than women to engage in infidelity, with rates for both sexes becoming increasingly similar. According to this theory, when people live within environments that are demanding and stressful, the need for bi-parental care is greater for increasing the survival of offspring.
Correspondingly, monogamy and commitment are more commonplace. On the other hand, when people live within environments that encompass little stress and threats to the viability of offspring, the need for serious and committed relations is lowered, and therefore promiscuity and infidelity are more common.
According to this theory, an area has a high sex ratio when there is a higher number of marriage-aged women to marriage-aged men and an area has a low sex ratio when there are more marriage-aged men. On the other hand, when sex ratios are low, promiscuity is less common because women are in demand and since they desire monogamy and commitment, in order for men to remain competitive in the pool of mates, they must respond to these desires.
Support for this theory comes from evidence showing higher divorce rates in countries with higher sex ratios and higher monogamy rates in countries with lower sex ratios. It is more common for men compared to women to engage in extradyadic relationships. In addition, recent research finds that differences in gender may possibly be explained by other mechanisms including power and sensations seeking.
For example, one study found that some women in more financially independent and higher positions of power, were also more likely to be more unfaithful to their partners. Gender differences[ edit ] There is currently debate in the field of evolutionary psychology whether an innate, evolved sex difference exists between men and women in response to an act of infidelity; this is often called a "sex difference".
Women, who do not face the risk of cuckoldry, are theorized to maximize their fitness by investing as much as possible in their offspring because they invest at least nine months of resources towards their offspring in pregnancy.
These conflicting strategies are theorized to have resulted in selection of different jealousy mechanisms that are designed to enhance the fitness of the respective gender. This style of questionnaire asks participants "yes or no" and "response A or response B" style questions about certain scenarios.
For example, a question might ask, "If you found your partner cheating on you would you be more upset by A the sexual involvement or B the emotional involvement". Many studies using forced choice questionnaires have found statistically significant results supporting an innate sex difference between men and women.
In consideration of the entire body of work on sex differences, C. Harris asserted that when methods other than forced-choice questionnaires are used to identify an innate sex difference, inconsistencies between studies begin to arise.
The results of these studies also depended on the context in which the participants were made to describe what type of jealousy they felt, as well as the intensity of their jealousy. According to Harris, a meta-analysis of multiple types of studies should indicate a convergence of evidence and multiple operationalizations. This is not the case, which raises the question as to the validity of forced-choice studies. DeSteno and Bartlett further support this argument by providing evidence which indicates that significant results of forced-choice studies may actually be an artifact of measurement; this finding would invalidate many of the claims made by those "in favor" of an "innate" sex difference.
One theory that has been hypothesized to explain why men and women both report more distress to emotional infidelity than sexual infidelity is borrowed from childhood attachment theories.
Studies have found that attachment styles of adults are consistent with their self-reported relationship histories. The authors propose that a social mechanism may be responsible for the observed results. In other words, replicable sex differences in emotion and sexual jealousy could be a function of a social function. Similar studies focusing on the masculinization and feminization by society also argue for a social explanation, while discounting an evolutionary explanation.
Anthropologist Bobbi Low says we are "slightly polygamous"; while Deborah Blum believes we are "ambiguously monogamous," and slowly moving away from the polygamous habits of our evolutionary ancestors. Some people may want to supplement a marriage, solve a sex problem, gather more attention, seek revenge, or have more excitement in the marriage. But based on Fisher's research, there also is a biological side to adultery.
This variation stems from the fact that societies differ in how they view extramarital affairs and jealousy. Therefore, when an individual feels jealousy towards another, it is usually because they are now sharing their primary source of attention and satisfaction.
However, variation can be seen when identifying the behaviors and actions that betray the role of primary attention satisfaction giver. For instance, in certain cultures if an individual goes out with another of the opposite gender, emotions of intense jealousy can result; however, in other cultures, this behavior is perfectly acceptable and is not given much thought. While many cultures report infidelity as wrong and admonish it, some are more tolerant of such behaviour.
These views are generally linked to the overall liberal nature of the society. For instance, Danish society is viewed as more liberal than many other cultures, and as such, have correlating liberal views on infidelity and extramarital affairs. In Danish society, having sex does not necessarily imply a deep emotional attachment.
As a result, infidelity does not carry such a severe negative connotation. The cultural difference is most likely due to the more restrictive nature of Chinese society, thus, making infidelity a more salient concern. Sexual promiscuity is more prominent in the United States, thus it follows that American society is more preoccupied with infidelity than Chinese society.
Even within Christianity in the United States , there are discrepancies as to how extramarital affairs are viewed. For instance, Protestants and Catholics do not view infidelity with equal severity. The conception of marriage is also markedly different; while in Roman Catholicism marriage is seen as an indissoluble sacramental bond and does not permit divorce even in cases of infidelity, most Protestant denominations allow for divorce and remarriage for infidelity or other reasons.
Ultimately, it was seen that adults that associated with a religion any denomination were found to view infidelity as much more distressing than those who were not affiliated with a religion.
Those that participated more heavily in their religions were even more conservative in their views on infidelity.
For example, Schmitt discusses how tribal cultures with higher pathogen stress are more likely to have polygynous marriage systems; whereas monogamous mating systems usually have relatively lower high-pathogen environments. Furthermore, within a "homogeneous culture," like that in the United States, factors like community size can be strong predictors of how infidelity is perceived.
Larger communities tend to care less about infidelity whereas small towns are much more concerned with such issues. For example, a cantina in a small, rural Mexican community is often viewed as a place where "decent" or "married" women do not go because of its semi-private nature.
Conversely, public spaces like the market or plaza are acceptable areas for heterosexual interaction. A smaller population size presents the threat of being publicly recognized for infidelity. However, within a larger community of the same Mexican society, entering a bar or watering hole would garner a different view. It would be deemed perfectly acceptable for both married and unmarried individuals to drink at a bar in a large city. These observations can be paralleled to rural and urban societies in the United States as well.
According to a survey of 16, individuals in 53 countries by David Schmitt , mate poaching happens significantly more frequently in Middle Eastern countries such as Turkey and Lebanon , and less frequently in East Asian countries such as China and Japan. This theory states that the sex that invests less in the offspring has more to gain from indiscriminate sexual behaviour.
This means that women, who typically invest more time and energy into raising their offspring 9 months of carrying offspring, breast feeding etc. Men on the other hand, have less parental investment and so they are driven towards indiscriminate sexual activity with multiple partners as such activity increases the likelihood of their reproduction.
It can however, still account for the occurrence of extradyadic sexual relationships among women. For example, a woman whose husband has fertilization difficulties can benefit from engaging in sexual activity outside of her relationship.
She can gain access to high-quality genes and still derive the benefit of parental investment from her husband or partner who is unknowingly investing in their illegitimate child. Jealousy is an emotion that can elicit strong responses. Cases have been commonly documented where sexual jealousy was a direct cause of murders and morbid jealousy.
It can be activated by the presence of interested and more desirable intrasexual rivals. It can function as a motivational mechanism that creates behavioral outputs to deter infidelity and abandonment. Looking at jealousy's physiological mechanism offers support for this idea. Jealousy is a form of stress response which has been shown to activate the sympathetic nervous system by increasing heart rate , blood pressure , and respiration.
Because infidelity imposed such a fitness cost, those who had the jealous emotional response, improved their fitness, and could pass down the jealousy module to the next generation. Researchers in favor of this defense mechanism speculate that in our ancestor's times, the act of sex or emotional infidelity is what triggered jealousy and therefore the signal detection would have happened only after infidelity had occurred, making jealousy an emotional by-product with no selective function.
This damage will impair the future benefits that individual can confer from the group and its individuals. Support for this defense mechanism comes from fieldwork by Hirsch and his colleagues that found that gossip about extramarital affairs in a small community in Mexico was particularly prevalent and devastating for reputation in this region. In this community, men having extramarital affairs did so in private areas with lower prevalence of women connected to the community, such as bars and brothels , both areas of which had a high risk of contracting sexually transmitted infections.
The Internet[ edit ] The proliferation of sex chat rooms and dating apps has increased the opportunity for people in committed relationships to engage in acts of infidelity on and off the Internet. A cyber affair is defined as "a romantic or sexual relationship initiated by online contact and maintained primarily via online communication". The majority of Americans believe that if a partner engaged in cybersex this constitutes as an act of infidelity. They found a significant sex difference as to whether participants chose sexual and emotional infidelity as more upsetting.
More men than women indicated that a partner's sexual involvement would upset them more than a partner's emotional bonding with someone else. Similarly, in the dilemma involving infidelity over the Internet, more men indicated their partner's sexual involvement would upset them more than a partner's emotional bonding with someone else.
Women, on the other hand, expressed more problems with emotional infidelity over the Internet than did men. A possible explanation is that our brain registers virtual and physical acts the same way and responds similarly.
The following factors were investigated: They include anonymous sexual interactionism, behavioral rationalization, and effortless avoidance: Anonymous sexual interactionism refers to these individuals' predilection for anonymous interactions of a sexual nature in chat rooms. The allure of anonymity gains extra importance for married individuals, who can enjoy relative safety to express fantasies and desires without being known or exposed.
Behavioral rationalization denotes the reasoning that chat room users present for conceiving their online behaviors' as innocent and harmless despite the secrecy and highly sexual nature. Effortless avoidance involves chat room users' avoidance of psychological discomfort by exchanging sexual messages with strangers.
Happily-married individuals also join such rooms. Even where infidelity is not a criminal offense, it may have legal implications in divorce cases; for example it may be a factor in property settlement , the custody of children, the denial of alimony , etc. The constitutionality of US criminal laws on adultery is unclear due to Supreme Court decisions in giving privacy of sexual intimacy to consenting adults, as well as broader implications of Lawrence v.
Adultery is declared to be illegal in 21 states. Such provisions have been condemned by the Council of Europe and the United Nations in recent years. The Council of Europe Recommendation Rec 5 of the Committee of Ministers to member states on the protection of women against violence states that member states should: Additionally, there is confusion as to what exactly constitutes infidelity.
Some consider that infidelity requires sexual intercourse; others that physical acts other than intercourse might constitute infidelity, and still others that emotional infidelity is possible without any physical acts whatsoever. Sexual fantasy with someone outside marriage Talking with an attractive stranger Flirting Meeting up without accompanying spouse s Playful touching.