The Evolution of Human Pair-Bonding, Friendship, and Sexual Attraction

Love Bonds

Michael R. Kauth

• Publisher: Routledge
• Year: 2020
• Print ISBN: 9780367427245
• eBook ISBN: 9781000226546
• Topic: Social Sciences
• Subtopic: Human Sexuality in Psychology
• Index: Social Sciences

The Evolution of Human Pair-Bonding, Friendship, and Sexual Attraction presents an evolutionary history of romantic love, male-female pair-bonding, same-sex friendship, and sexual attraction, drawing on sexuality research, gay and lesbian studies, history, literature, anthropology, and evolutionary science.

Employing evolutionary theory as a framework, close same-sex friendship is examined as an adaptive trait that has harnessed love, affection, and sexual pleasure to navigate same-sex environments for both men and women, ultimately benefiting their reproductive success and promoting the inheritance of traits for friendship. Chapters consider the desire to form close same-sex friendships and ask if this is embedded in our biology, concluding that most humans have the capacity to form loving, meaningful, and sexual relationships with men and women.

This book takes on a unique interdisciplinary approach and is essential reading for those studying and working in sexuality research, anthropology, sociology, evolutionary psychology, and gay and lesbian studies. It will also be of interest to marriage and family therapists as well as sex therapists.

Chapter 1

Initial Introductions

Human relationships fascinate me, particularly erotic and loving relationships both in the present and the past. I am curious how people have related to each other to survive and find comfort, safety, or meaning in their lives, along with pleasure. Specifically, I am curious why humans so readily form romantic pair-bonds and close friendships. Both are passionate, intimate, long-term attachments. Are they related? What are the functions of romantic pair-bonds and close friendships? Academic disciplines either have very different explanations for these phenomena or none at all. There are few common threads across disciplines. Some disciplines, like the evolutionary sciences, focus explanations on the far distant past and on reproduction, while others, like sexual science, concentrate on the present and on sexual attraction and pleasure, mostly ignoring human evolution and history. Other disciplines, like history, simply tell the story in context, often with a sociopolitical narrative, and still others, like gender studies, critical theory (à la Foucault), and some gay and lesbian studies, see human reproductive or mating pair-bonds and close friendships as unique to each culture but in relationship to social conventions, with no underlying or universal basis. I find these explanations incongruent, incomplete, and unsatisfying. In this book, I attempt to present an integrated, interdisciplinary account of the origin, function, and history of human reproductive, mating pair-bonds and devoted same-sex friendships across cultures. I offer a narrative analysis that integrates several disciplines. I view erotic/sexual attraction and love as the mechanisms that created these critical, intimate, long-term attachments that have been so prevalent and successful through human history. Social customs then emerged to further support these vital relationships. I also hope to demonstrate that Western cultural centrism and current conceptions of marriage, friendship, and sexuality—how we view ourselves—have blinded us and misled scientists into ignoring or reimagining the past to conform to our narrow modern views about sexual kinds of people. In the end, I propose a paradigm shift away from siloed academic disciplines and contemporary Western centrism and toward an integrated, interdisciplinary approach to human sexuality, relationships, and evolution. This is easier said than done, but much more interesting than explaining human phenomena from a singular perspective.

With regards to human relationships, humans are remarkably social creatures who, for the most part, like to be together, unlike some other animals. Humans often maintain close relationships with kin all their lives and even stay connected to extended kin. Humans also show an amazing affinity for close associations with non-relatives. Generally, people like other people and prefer to live in groups, close to each other. There are individual exceptions, of course, and people often distrust out-groups. However, cooperative, personal human associations are more the rule than the exception. Other species live in groups. Many species of fish live in schools. Many kinds of birds flock together. Dolphins, penguins, flamingoes, elephants, horses, wolves, deer, baboons, and chimpanzees also prefer to live in groups. Living in groups is an effective strategy to protect against predators. Group living also facilitates food acquisition and care for vulnerable young. Anthropologists generally agree that humans live in groups for many of the same reasons that benefit other species that live in groups (Gurven, 2012; Marlowe, 2012).

Beyond just group-living, humans pursue close companionship in at least two specific forms. Throughout history, humans have formed passionate, intimate, long-term relationships with non-relatives in mating pair-bonds and devoted friendships. Other species sometimes form long-term mating pair-bonds. Many birds, for example, mate for life. Mammals do this less often, preferring other mating strategies. Less than 10% of mammals form long-term mating pair-bonds (Lukas & Clutton-Brock, 2013). Individuals in many species also form long-term preferential alliances in what looks like friendships. For instance, dolphins, elephants, and chimpanzees frequently form long-term peer alliances (Seyfarth & Cheney, 2012). Humans, however, form long-term different-sex (male-female) mating pair-bonds and devoted same-sex friendships on an extraordinary scale.

Both different-sex mating pair-bonds (or marriage) and same-sex friendships are pervasive across human cultures and take various forms (Beer, 2001; Brown, 1991). I am most interested in socially monogamous mating pair-bonds as erotic and loving relationships. Social monogamy refers to committed togetherness, not sexual exclusivity, but more on that in later chapters. Anthropologists note that, in many cultures, humans spend a considerable amount of time and energy longing for, locating, choosing, and keeping a reproductive mate. Volumes have been written about this process. Whole families and the community are sometimes involved in these efforts, and elaborate public ceremonies formalize and celebrate the pair-bond. Marriage is the cultural construction for formal mating pair-bonds, but marriage is quite varied. Every culture has a tradition of marriage. The United States has one of the highest annual marriage rates (6.9/1,000) in the world, with nearly 2.5 million marriages each year (Centers for Disease Control, 2017a). Among European countries, Lithuania boasts the highest annual marriage rate at 7.5 marriages per 1,000 citizens (Eurostat, 2019). Globally, formal marriage ceremonies, or weddings, are a $300 billion-dollar industry that employs approximately 750,000 people (Bourque, 2017). Although marriage rates have been on the decline in the United States and worldwide in recent years, marriage is far from disappearing. Increasingly, couples opt to live together and even start a family without the formal ritual of marriage. Living together in a committed family relationship is a mating pair-bond just the same.

Anthropologists also show that close personal relationships also take a variety of forms, just like marriage. I am most interested in affectionate long-term attachments between unrelated same-sex individuals that are both erotic and loving. I will argue that friendship may be just as valuable and necessary as marriage, although friendship as a topic has received far less social and scholarly attention than finding a reproductive mate. In many past cultures, devoted male friendships—passionate, intimate, long-term attachments—have been formalized in public ceremonies and recognized by the community (Williams, 1992a). Across historical cultures, devoted male friends have been called “sworn brothers”, “adoptive brothers”, “blood brothers”, or other terms (Miller & Donovan, 2009/2013). Historians have recorded devoted male friendships in many past cultures, and uniformly these friendships have been revered. While people today value good friends, contemporary cultures no longer recognize “sworn brothers” or romantic same-sex friendships as in previous cultures. Modern friendships have been de-eroticized, while people themselves have become sexualized based on their sexual attractions. Today, Western people often identify themselves by their sexual attractions, consistent with the modern idea that people are their sexuality (Halperin, 2012). This idea is perpetuated, accidentally or on purpose, by sexual scientists who focus on individual differences between sexual kinds of people. Conventional sexual identities include heterosexual (different-sex attracted), gay or lesbian (same-sex attracted), and bisexual (both different- and same-sex attracted). Less conventional, idiosyncratic identity terms narrow or broaden the scope of one’s attractions, such as asexual (no attraction), queer (not exclusively heterosexual), pansexual (attraction to people regardless of gender), and even sapiosexual (attraction to highly intelligent people). Because people have been sexualized and friendships have been de-eroticized in contemporary cultures, friends may find themselves worrying that affection or intimacy will be interpreted by their friend or by observers as “gay”, thus, jeopardizing the friendship.

Gender and gay and lesbian scholars remind us that, for the past several hundred years in Western culture, same-sex sexual attraction and behavior, especially among males, have been severely stigmatized and punished. While Western cultures have experienced tremendous social changes in recognizing the rights and dignity of lesbian, gay, bisexual, transgender, and queer (LGBTQ) people in recent years, these are relatively recent changes, and not everyone has benefited. Gay and queer kids still get kicked out of their homes, and sexual orientation-motivated violence is the third most common hate crime in the United States (Federal Bureau of Investigation, 2019). In many states, LGBTQ Americans can be fired from their jobs because their employer dislikes their sexuality or gender expression. Few states have LGBTQ discrimination protections (Freedom for All Americans, 2018). At the same time, conservative religious groups demand the right to discriminate against LGBTQ people as “religious freedom” (People for the American Way, 2019).

Anthropologists and gay and lesbian historians have noted that contemporary Western culture conceptualizes friendship and marriage quite differently than it did even a few hundred years ago and differently from most historical cultures. For instance, contemporary culture allows mixed sex socializing and friendships, as well as gay marriages. Today, Western people often think of their spouse as their best friend and view their best friend more like a cousin who is fun to have around, but not too familiar. Given that marriage and friendships have long histories, are these recent social changes in Western culture simply superficial? Of course, cultures define marriage and friendships somewhat differently. However, knowing human cultural histories can aide in spotting persistent social characteristics from variable ones. Knowing human cultural histories also helps in identifying beliefs, customs, and discourse that create a social reality for any particular culture and point in time. What, if anything, is persistent about human mating pair-bonds and devoted same-sex friendships through history?

The evolutionary sciences attempt to explain how we got to this point by looking at the distant past: that is, the reason why humans evolved to look, think, and act like we do is a function of solving ancient problems of survival and reproduction. Characteristics that have persisted through history and across cultures, like reproductive mating pair-bonds and devoted same-sex friendships, may be adaptive. Backward engineering these traits may reveal clues to specific challenges faced by our early ancestors in their environments. Thus, an evolutionary analysis of human mating pair-bonds and devoted friendships can help us understand our development and how we came to think and behave in certain ways. An evolutionary analysis provides a broader, deeper context of human development. However, an evolutionary analysis cannot tell us if evolved traits are adaptive today because the environment that most people live in today is quite different from the environment of our early ancestors. In fact, some adaptive traits, evolved in ancient, long-gone environments, may conflict with life in contemporary environments. If evolved human traits may not be adaptive today because our modern manufactured environment is so different from the savannahs of Africa where the traits developed, then why undertake an evolutionary analysis? Is an evolutionary analysis really worthwhile? I think it is. We are better informed when we understand that human bodies and brains are works in progress but adapted to environments that are wildly different from today. Our bodies and brains are constantly playing catch-up with the demands of the ecology, and now our social culture and technology are evolving at an ever accelerating pace. Knowing human evolutionary history can help us be more understanding when evolved human traits conflict with changing social environments and social values.

Academic disciplines like evolutionary biology, anthropology, developmental biology, paleontology, archaeology, genetics, evolutionary psychology, ancient history, classical studies, literature, art history, sexual science, gender studies and critical theory, and gay and lesbian studies, all referenced in this text, use different methodologies to examine different phenomena at different points in time based on different assumptions. In many ways, these disciplines present partial truths. No discipline has the Truth, although the rigor and precision of some disciplines allow them to be more confident of what they know. Each discipline is a little like the blind men and the elephant; it can only describe the part of the phenomenon it examines. No one experiences the entire animal. In a sense, I am collecting and integrating perspectives from different disciplines to piece together a more comprehensive picture of the origin, function, and history of human mating pair-bonds and same-sex friendships. I am looking for common threads through disciplines and historical cultures. I approach this task cautiously, because interpreting findings from different fields is fraught with risk. What is more, the pieces of data come from different puzzles. While there are links between puzzles, the final puzzle picture, like the one presented here, can only be strongly suggestive because the fit is imperfect, and there are many missing pieces.

In this book, I examine human different-sex mating pair-bonds and devoted same-sex friendships as adaptations. From an evolutionary framework, the adaptive value of male-female mating pair-bonds seems obvious since these relationships directly benefit reproductive success, although there are alternative mating strategies. The adaptive value of devoted same-sex friendships may be less obvious but makes sense in the context of sex-segregated environments. Drawing on findings from several evolutionary sciences, I will show that at least since the early division of labor, and perhaps long before that, humans have largely lived in sex-segregated environments. In these environments, devoted same-sex friendships directly benefited survival by facilitating navigation of the same-sex social environment to defend against threat and acquire resources. Further, devoted same-sex friendships likely indirectly benefited reproductive success by facilitating the acquisition of a quality mate as well as resources to protect and support one’s family. Over time, these adaptive traits spread through the population, and social customs developed to reinforce marriage and close friendships. As a result, the desires to have a reproductive mate and form a family and make a close, long-term friend is written in our biology, while culture determines the forms these attachments take.

As part of this story, I also explore how evolution exploited erotic/sexual attraction, love, and sexual pleasure to support both human mating pair-bonds and same-sex friendships. Drawing on anthropological studies and field observations, I will show the extensive prevalence of devoted male friendships among contemporary hunter-gatherers and among native people upon first contact. Drawing on ancient history, classical studies, and literature, I will show a long history of devoted male friendships across diverse cultures up to the near present. I will introduce limited evidence of close female friendships because this information is quite scarce. A major implication of these findings and the idea that devoted same-sex friendships are an adaptation is that most men (and probably most women) have the capacity for attraction to male and female partners. Yet this conclusion runs counter to how Western culture views sexuality and counter to sexual science research that shows most people identify as exclusively heterosexual. How can that be? Drawing on data from sexual science, I will show that sexual arousal patterns for men and women show much more variability than is predicted from self-reports of exclusive attractions. Drawing on gender and gay and lesbian studies, I observe that culture has a lot to do with how people experience sexual attraction (and which kinds) and how they define themselves. Scientists exist within the same culture and even perpetuate social conventions! In the end, I hope to present a fuller, richer account of reproductive mating pair-bonds, same-sex friendships, and human sexuality.

Building on the Past Work of Scholars

This book builds on the scholarship of many brilliant, insightful experts. While this work is presented in later chapters, I want to highlight a few texts that significantly influenced my thinking about sexual attraction, mating, and friendship. Among these is an engaging history of the evolut...

Table of contents

• Cover
• Half-Title
• Title
• Copyright
• Contents
• List of illustrations
• 1 Initial Introductions
• 2 Love, Sex, Marriage, and Family Different-Sex Mating Pair-Bonds as an Adaptation
• 3 Friends with Benefits Devoted Same-Sex Friendship as an Adaptation
• 4 Life Partners A Brief History of Devoted Friendships
• 5 Labeling Love and People Sexual Attractions and Identities
• Index