This chapter focuses on how motivated cognition – the tendency for people to think in ways that are consistent with their goals – supports relationship maintenance. It starts with an overview of the assortment of strategies that people use to maintain their close relationships, which lay the foundation for this chapter and subsequent chapters. Then, it explicates the specific biases and illusions that people tend to have about their partners (e.g., seeing partners as particularly physically attractive, projecting ideal traits onto one’s partner) and their relationships (e.g., perceiving one’s own relationship as superior to others). This chapter also reviews empirical evidence describing the implications of this motivated inaccuracy for perceivers and their partners’ relationship experiences. This chapter also describes how biased perceptions extend to potential alternatives, leading people to ignore and devalue attractive alternative partners. It concludes with a discussion of contextual factors that shape the extent to which people engage in motivated cognition and the specific consequences of bias and illusion in relationships.

This chapter explores central questions of relationship dissolution: Why and how do people voluntarily breakup? What are the consequences of a close relationship ending? How do people recover and move on from difficult relationship endings? It begins with a discussion of the typical precursors of relationship dissolution, including problems with “me” or “you” (e.g., personality traits, attachment orientation, difficult habits), problems with “us” (e.g., romantic disengagement, disillusionment, incompatibility, infidelity), and problems in the context (e.g., financial stress, incarceration, parenting challenges). Then, it reviews the process of breaking up, including strategies people use to end their relationships. Finally, this chapter ends with a summary of the common immediate negative consequences of relationship dissolution and the common long-term recovery process (as well as diverse post-dissolution outcomes).

This chapter explores infidelity in Black committed relationships. Research indicates that the instability of Black relationships is directly related to the effects of racial trauma that Black men and women continue to endure. Due to the emotional and psychological wounds caused by systemic oppression, internalized stereotypes, and other factors, Black men and women often wear a mask, ultimately suppressing their authentic selves. A sociological phenomenon called covering is discussed to frame, expand, and make meaning of the ways Black men and women in relationship have learned to survive and protect themselves from further emotional bruising. A case study using Narrative Therapy addresses covering while attending to the language used to shape a couple’s reality. Discovering an alternative solution to other possibilities expands the couple’s sense of self and other to ultimately redefine their story.

In species with internal female fertilization, males face the problem of paternity uncertainty, which refers to the risk of investing in unrelated offspring. As such, a partner’s sexual infidelity may be particularly damaging for males given that it may result in allocating resources to genetically unrelated offspring, reducing a male’s inclusive fitness. As such, males invest considerable time and effort to retain their mates. Mate retention tactics involve cost-inflicting strategies that operate by reducing the partner’s self-perceived value to prevent the partner from leaving the partnership, and benefit-provisioning strategies that operate by boosting a partner’s self-esteem and improving relationship satisfaction. In this chapter, first, we discuss the benefits that men gain from long-term relationships, which include increased probability of paternity, prolonged proximity and sexual access to a partner, and increased probability of attracting a high-quality partner. Second, we discuss the main costs of infidelity for males, including the risk of investing in an unrelated child as well as costs to his reputation and future mating opportunities. Third, we define and discuss a taxonomy of mate retention tactics and explain that a male’s mate retention tactics are expected to respond to his female’s partner preferences, at least partly. Indeed, males have been found to engage in tactics such as resource display given that females value mates that are able and willing to provision them and their offspring with resources. Empirical evidence has also, surprisingly, found that men, more than women, engage in strategies such as submission and debasement. Empirical evidence also suggests that men also use threats and violence directed to rivals more than women do. Our review also demonstrates that males engage in both benefit-provisioning and cost-inflicting mate-retention strategies, and that the type of strategy chosen as well as its intensity is partly dependent on a man’s mate value and his ability to acquire resources. Finally, we discuss some of the main environmental factors that may influence the mate retention tactics displayed by males, including partner mate value and perceived infidelity threat.

Mate retention behaviours are intended to prevent a partner’s infidelity or defection from a relationship. In humans, women’s reproductive success is importantly affected by their ability to retain a partner. Furthermore, it is beneficial for a woman to retain a partner who is willing to protect and provide for her, her offspring, and her family, and who is a cooperative partner. Women can achieve this by deploying cost-inflicting or benefit-provisioning mate retention behaviours. The benefits women provide include care for their appearance: women enhance their appearance for their partners to embody male preferences for attractive and young mates. Appearance enhancement takes various forms, including cosmetic surgeries, application of makeup, fashionable clothing, use of perfumes, and specific movements aimed at displaying attractiveness. Women use these behaviours in all phases of a relationship, to attract a mate, to seduce and a mate, and to retain a mate. Appearance enhancement is, however, also subjected to monitoring and penalisation by other women in the context of intrasexual competition. Women therefore often opt for cosmetic procedures with moderate effects which do not emphasise their sexual appeal, but help increase their prestige and status. Other behaviours women use to retain a mate include the use of sexual behaviour and, in particular, oral sex and pretending orgasm. As hinted above, women also use mate retention behaviours that are costly for their partner, such as punishment of their partner’s infidelity threat or indirect aggression, including derogation of their partner or rivals. Despite women’s physical strength inferiority to men, physical aggression is sometimes performed by women against their partner, although it results in injuries less frequently than does male domestic violence. Women’s higher anxiety and, especially, their skill at identifying the mental states of others and responding with appropriate emotions, enable them to be efficient at indirect and manipulative mate retention behaviours. The same skills and abilities help women keep the partner satisfied and the romantic dyad functioning as long as the relationship remains beneficial for the couple.

Mate poaching is a form of romantic attraction in humans defined as a “behavior intended to attract someone who is already in a romantic relationship” (Schmitt & Buss, 2001; p. 894). Two essential criteria to mate poaching are that a romantic relationship from which a poached individual comes is monogamous, and that a poacher is aware that the relationship he/she is poaching from is exclusive. Mate poaching is a reasonably common practice to form new short-term and long-term romantic relationships. In most world regions, women report less frequent poaching attempts for short-term and long-term relationships than men do. Additionally, higher proportions of women report poaching attempts for a long-term than for a short-term relationship, whereas almost equal proportions of men report poaching attempts for long-term and short-term relationships. Women are less frequently successfully poached than men for both short-term and long-term relationships, but more women succumb to long-term than short-term poaching attempts. Research on sex differences shows that some environmental factors moderate women’s short-term mate poaching. Women are more inclined to short-term mate poaching in resource-rich environments, in societies with higher levels of gender equality and in those where women outnumber men. A number of other biological, psychological, and social factors affect women’s mate poaching experiences such as phase of their menstrual cycle, the level of commitment to their romantic partners, mate value of their current partners and poachers, previous friendship with poachers, mate-guarding and infidelity detection, enticement and disguising tactics, mate copying, and personality characteristics. The relationships between mate poaching experiences and personality characteristics are small to moderate, the largest between mate poaching and the Dark triad traits, followed by several of the Sexy Seven dimensions, five-factor personality traits, sociosexuality, and attachment styles. As a poacher or a poached, women may be exposed to various costs such as jealousy, violent acts from their partner ranging from subtle violence to rape and uxoricide, feelings of shame, and social exclusion. Their new relationships may be characterized by lower satisfaction and commitment, higher jealousy and infidelity, and their children may suffer lower investment and physical abuse from a stepfather. As victims of poaching, women may experience a loss of a high-quality partner and his resources. One of the main benefits of women’s mate poaching can be derived from the dual mating hypothesis. It states that by simultaneous pursuing of short-term and long-term mating strategies women may obtain investment from a regular partner and superior genes from an affair partner. Growing evidence suggests that one function of women’s mate poaching is breaking up with one partner and remating with another, known as the mate switching hypothesis. Other possible benefits of women’s mate poaching are taking pride in the conquest of a long-term relationship, taking revenge on a rival, gaining an already proven mate, obscuring paternity, and increasing genetic variability of offspring.

Mate poaching is engaging in premeditated behaviors to attract either short-term or long-term mates by luring them away from their already established relationship. It is unique as compared to other ways to initiate a relationship because it involves specific behaviours and consequences, given that the target is already mated. Despite the potential for negative outcomes related to the discovery of the poacher’s attempt, including homicide and intimate partner violence, it is a common occurrence. Depending on the context, cultural group, and sex, rates vary from slightly under 30 percent to over 60 percent for how many people report having attempted mate poaching. During the past two decades, there has been a noteworthy growth in our understanding of mate poaching, and this chapter will present a comprehensive review of those developments. We focus specifically on men’s use of mate poaching, with the goal of explaining how it has led to advantages over evolutionary time. There are many reasons to examine men separately from women. For example, data reveal that men, more than women, report attempting to poach short-term mates, and that they have succumbed to poaching attempts in short-term contexts. These differences imply that men receive different benefits from poaching, and being poached, than women. We start with an overview to show how frequently it occurs and some of the general traits of those who poach. Then, we use a functional approach to investigate the problems that mate poaching solves for men, as well as the associated costs. This approach allows us to document which strategies are the most effective for poaching, as well as the identity of potential targets. We conclude with suggestions for future research, including the need to be inclusive in studying mate poaching so as to more fully encompass a variety of sexual orientations, and how mate poaching leads to direct reproductive success via increased numbers of children.

Extrapair sex, although not a dominant human mating strategy, has been a part of our mating landscape throughout human history. Although prevalence rates vary across studies, a conservative estimate is that at least 1 out of 5 persons have cheated on a committed partner. In this chapter I discuss theories and evidence addressing extrapair interest and behavior (i.e., cheating on a committed partner) as produced by adaptations. Topics include the costs and benefits of extrapair behavior, comparisons to nonhuman animal extrapair behavior, sex differences, and purported female cyclical variations in extrapair orientation. I briefly discuss proximate factors that predict proclivity to cheat. I also touch on infidelity advertisement, cheating detection, forgiving a partner’s infidelity, and infidelity in popular culture. I conclude with some observations about the state of the field. Regardless of causes and correlates, infidelity can be costly, yet humans remain interested in and intrigued by the phenomenon.

Men sometimes engage in noncopulatory sexual behaviors, such as cunnilingus and other kinds of sexual foreplay. Men involved in long-term romantic relationships, in particular, tend to provision their partners with oral sex. Potential adaptive functions of cunnilingus in humans are discussed with a focus on the hypothesis that men use oral sex provisioning as part of a general benefit-provisioning, long-term mating strategy. Other potential adaptive functions are also considered, including the infidelity detection hypothesis and several hypotheses concerning sperm competition adaptations. Some research has proposed the possibility that men may use oral sex as a form of infidelity detection, wherein they might be able to smell or taste the semen of rival males in their partner’s vagina. Other research has posited that men might perform cunnilingus in order to induce orgasm in their partners, thereby increasing the amount of sperm retained in her reproductive tract after ejaculation. Still others have suggested that men might perform cunnilingus to increase their own arousal, thus increasing their subsequent ejaculate volume. These adaptive perspectives are couched within the wider literature on oral sex, which includes data regarding the frequency of oral sex in adolescent, preindustrial and non-Western samples, as well as women’s desire for receiving oral sex. Regarding the relative infrequency of cunnilingus in preindustrial and non-Western samples, in particular, men’s provisioning of oral sex is considered as potentially being a part of an evolved cognition for benefit-provisioning mate retention in general, rather than oral sex itself serving a specific adaptive function. Specifically, oral sex may be one type of sexual favor that men, especially those in Western cultures, sometimes provide to their long-term partners. Additional data regarding the increased sexual and relationship satisfaction in women who engage in a wider variety of sexual practices and who more frequently experience orgasm further supports the mate retention hypothesis of men’s provisioning of oral sex. Nevertheless, the available literature investigating these potential adaptive functions is currently insufficient to draw any decisive conclusions. Finally, gaps in the current literature and suggestions for future research that may help determine the evolved nature of men’s oral sex provisioning are discussed.

“Dear John” letters have loomed large in American war-lore ever since GIs first coined the phrase in World War II. Receiving a break-up note from a wife, fiancée, or girlfriend has come to appear a rite of passage for men in uniform. The motif of female treachery and male tragedy circulates both in the stories servicemen and veterans tell one another and in US culture more broadly – in pop music, movies, and novels. Yet no prior author has devoted a book to the “Dear John” phenomenon. That virtually no bona fide specimens exist in archival collections helps explain this lacuna. But the fact that so many “Dear Johns” were physically destroyed soon after receipt doesn‘t make these letters impossible to study. Instead of regarding Dear Johns as a female-authored epistolary genre, we should conceive these letters as the product of a male vernacular tradition. Men have told us most of what we know about how and why women composed these letters, and the effects they‘ve had on recipients. This book explores the interplay between letter-writing and story-telling, inviting readers to contemplate why love is so hard to sustain in wartime.

Patriotic war culture has routinely touted the symbiosis between mail and morale. Disciplinarians of wartime feeling have issued reams of advice about how to “write right!” in order to sustain men’s esprit and keep love alive despite distance and danger. Above all, military and civilian opinion-leaders alike have strenuously and repeatedly warned women against dispatching Dear Johns to men serving overseas. These prompts have taken many forms: explicit guidance from newspaper and magazine columnists, marriage counselors, government bodies, and voluntary agencies (like the YMCA and Red Cross) as well as pointed cues about emotional etiquette supplied by popular music, radio and television shows, and Hollywood movies. This chapter probes the challenges of sustaining long-distance love at war – difficulties often minimized by wartime advice-givers, but unmistakable to men and women who have tried, and sometimes failed, to keep intimate relationships intact. It also considers how far prescriptions issued to “waiting women” have changed since the 1940s, proposing that there’s been considerable continuity, despite radical shifts in dating behavior and marital norms in US society.

Unlike modern originalists, Justice Joseph Story (1779–1845) endorsed the maxim that “Christianity is a part of the common law,” and he seems thus to have considered Christianity deeply entangled with the Constitution. A Harvard graduate and Massachusetts Unitarian, he did not consider the Constitution bound to any specific Christian orthodoxy. Rather, by the Revolution, American Christianity itself had become tolerant of differences in doctrine and worship, while sharing an understanding of moral duty, embodied in the common law. Thus he could at once subscribe to the proposition that Christianity is a part of the common law and decide religion cases so as to uphold the separation of church and state, protecting church property from state interference, and protecting a municipally-run school from clerical influence. On the issue of slavery, his commitments to a living faith and to a settled Constitution collided, calling into question the Christian constitutionalism to which he devoted his professional life.