Courtship and Pair-Bonds

The Evolution of Courtship Rituals and Pair-Bonding in Humans

Evelyn Waterhouse

Psych 3P37

Human Evolution

The Evolution of Courtship Rituals and Pair-Bonding in Humans

  There is a popular misconception that heterosexual males and females are more promiscuous today than they were before the advent of dating apps. This is not true. There has been no change in the number of promiscuous tendencies among heterosexual males and females. This paper will help explain how this happened. In particular, this paper will argue that gene adaptation makes most humans predisposed towards pair-bonding behaviour, which creates an evolutionary shift from promiscuity to monogamy. This paper recognizes that there are many factors behind human habits regarding promiscuity; however, this paper will focus on biological factors contributing to this phenomenon. This paper does not attempt to be a comprehensive study on this topic; however, this paper will present some initial findings based on a literature review. Furthermore, this paper will provide recommendations for future research.

Dating apps have significantly disrupted the dating scene in the world today. However, this disruption is ill-understood.  A 2018 study on dating app users found that people who used these apps tend to be more promiscuous than people who did not use the apps; however, the appearance of dating apps did not shift the overall tendency of the population to be more or less promiscuous (Botnen et al., 2018). This same study concluded that dating apps only provide an alternative venue (instead of a bar, for example) for promiscuous people to find a short-term sexual partner. (Botnen et al., 2018). Furthermore, based on this study, one can infer that heterosexual males and females wishing to develop long-term monogamous relationships are not on dating apps.

Dating apps are just one way in which human courtship rituals are evolving. Darwin's natural selection theory suggests that individuals vary, and over time, will increase and create changes over generations. Darwin's natural selection theory includes inherited genes, the "fitness" of offspring in which it refers to the ability to survive and reproduce (Darwin 1859). In part, courtship rituals among heterosexual males and females can be described by changes developing in their genes. Genetic evolution in the human brain that promotes pair bonding has created an evolutionary shift from promiscuity to monogamy among humans.

Pair-bonding is a long-term association of two individuals that includes a sexual relationship. Humans refer to this pair-bonding as marriage cross-culturally, but married individuals are not necessarily pair-bonded. There are many benefits of pair bonding for humans, including economic, reproductive, and societal. Advances in technology allow evolutionary researchers to better understand human pair-bonding by enabling them to dig into humans' minds (and other mammals) using functional Magnetic Resonance Imaging (fMRI). The brain allows for the neural correlations associated with romantic attraction. Before fMRI technology, research was conducted by observation of behaviours. Research on monogamous voles is a foundational model for how genes can influence social behaviour vital for reproduction. Human social bonds between parents and children are expected to lengthen the parent-child lifetime (Young, L. 2003). Evolution in pair-bonding by humans through activation of V1aR respecters would give light to the possibility of human development by natural selection.

Pair-bonding is essential for parental care, which is embraced by both sexes to ensure offspring survival. Bendesky et al. (2017) used quantitative genetics to study the distinction between monogamous mice and non-monogamous mice to ensure offspring survival and identified 12 genomic regions that affect parental care. Parental behaviour is not uniform among individuals or between sexes. A particularly variable feature is the role played by a father in child-rearing, which occurs in monogamous species but not promiscuous ones. Among mice, the desired behaviours include retrieving, huddling, nursing and grooming pups and building a nest. A study on monogamous and promiscuous voles found that the chemicals vasopressin and oxytocin play a critical role in promoting pair-bonding (Bendesky et al., 2017). The spatial distribution of the vasopressin 1a receptor in the male brain is associated with pair-bonding behaviour changes (Bendesky et al., 2017). Oxytocin and vasopressin's role in females is already well understood due to pregnancy-related activation (Bendesky et al., 2017).

Nevertheless, monogamous males are more involved in parenting due to their brain's chemical rewards from said behaviour (Bendesky et al., 2017). Therefore, this study demonstrates that monogamy and parenthood are intimately related. Humans are naturally predisposed to monogamy to procreate.

However, humans must first engage in courtship before beginning to pair-bond. According to Tinbergen (1951), evolutionary psychology can be analyzed as a process consisting of cause, development, function and evolution. To better understand pair bonding and its effects on promiscuity, one must first understand human courtship rituals' function and evolution. The primary biological function of courtship is the optimization of reproductive success of the people involved in a relationship, Grammar (1989). Within the context of a sociobiological process, courtship is the notion of finding a potential long-term mate for child-rearing. Pair-bonding, meanwhile, cements this relationship. According to Grammar (1989), both partners' first condition is sexual attraction, which increases reproductive success. To express an interest in another person is a sexual advertisement, which males mainly do, and to a degree, some females.

Sexual advertisement is a concept developed by Maynard-Smith (1974) in the theory of games. The theory of games is ritualized behaviour that can evolve by individual selection. This concept has two types of distinguished behaviours, "tournaments" and "displays." Maynard-Smith (1974). A tournament is defined as a contest with physical contact.

An example would be two male deer interlocking their antlers and a pushing match, but no serious injury occurs. The victory will go to the more prominent, more vigorous and healthier deer. The tournament's ritualized behaviours were enough to settle conflicts, and no need to evolve more dangerous tactics. No physical contact takes place in a display and no information about who would win if the display escalated to a potential mate. The "winner" is the one who lasts longer in the display (Maynard-Smith 1974). In the human evolution of courtship rituals, such as "tournaments" and "displays, " human males with elevated testosterone levels around females show more interest in women, smile more, and make more eye contact (Van der Meij et al., 2012). Human males display their dominant status in social situations, such as a bar or social events, by quick and direct eye contact, changing locations often, sharing more about themselves, and speaking longer with a woman when interested in dating her (Van der Meij et al., 2012). The transition from courtship rituals to pair bonding is a biological factor that has evolved in the brain.

According to Fisher (2002), three discrete interrelated emotion-motivation systems in the mammalian brain are used for mating, reproduction, and parenting. The first is lust (libido activation), the desire for sexual gratification, which can be the driving factor for attracting a mate in males, confirming the observations of Maynard-Smith (1974).  The second is attraction, which characterizes increased energy and focused attention on a preferred mating partner. The third is attachment characterized by nest building, mutual territory defence, mutual feeding and grooming, maintaining close proximity, experiencing separation anxiety, and sharing parental chores. The attachment also experiences feelings of calm, security, social comfort and emotional union. (Fisher 1998). Fisher (2002) also indicts the three emotion-motivation systems of lust, attraction and attachment in Homo sapiens operate independently of one another. Researchers administered testosterone to increase sexual desire in middle-aged men and women and observed the response (Sherwin & Gelfand, 1987: Gelfand & Brender, 1985).  Both men and women increased sexual thoughts and activity but did not report feelings of increased romantic passion or increased attachment to the sexual partner (Sherwin & Gelfand, 1987: Gelfand & Brender, 1985). Also, men and women may express a deep emotional attachment towards a long-term spouse but express attraction for someone else and feel the sex drive in response to visual, verbal or mental stimuli unrelated to either partner. Both sexes can perform coitus with a person they are not "in love" with and still be "in love" within which they have no sexual contact (Fisher 2002). These behaviours are not in tune with our society's acceptable practices. However, some will argue that because of our physical biology and our social acceptance of the above behaviours, we see a rise in divorce due to infidelity, young adults having more personal relationships (sex without commitment). Waiting to marry, based on the observation of parental behaviours, and contemplating having children. This indicates that people yearn for a bond with someone else.

This desire for a bond can be illustrated by what happens when such a bond abruptly ends. As stated earlier, emotion plays a role in human relationships. A study by Fisher (2010) on attachment and addiction made an unexpected finding. Activity associated with a specific distribution pattern of vasopressin V1aR receptors, linked with pair-bonding and attachment behaviours in monogamous prairie voles, was found in participants' rejected in love. The rejected participants in love developed an evolved gene that activated the V1aR receptors, but the rejector did not. This shows that there are chemical changes in the body that stem from our romantic relationships' success or failure.

Furthermore, the decrease in brain activity is related to the number of months since the breakup; humans increase dependence on the romantic relationship's length—the lack of daily interaction with the rejecting individual decreases over time, which lowers the posterior sensorimotor activity (Aron et al. 2005a). These findings correlate with the result in a study conducted by Bendesky et al. 2017 that the length of time away from a mating partner will provide the necessary break to pair-bond to another. The discovery of this particular distribution pattern in the human brain suggested a feeling of attachment (Fisher 2010). The V1aR receptors activation may lead us to believe that individual humans can evolve to be monogamous and are not promiscuous. Promiscuous white-footed mice and rhesus monkeys do not have the V1aR receptors associated with pair-bonding (Bester-Meredith et al. 1999). Thus, it is no surprise that they are not monogamous while humans are.

This paper demonstrated that dating apps' advent did not result in a greater tendency towards promiscuity among humans. This paper also explored how a combination of genetics and chemical rewards leads humans to be predisposed towards monogamy. This can explain in part why humans did not become more promiscuous despite the new tools available for arranging hookups and casual sex.

Further Research

According to Carter et al. (2018), genetic monogamy is rare, and monogamy can exist without sexual fidelity. Carter states that it has become common to use the term "social monogamy" to describe a cluster of social features. These features are lasting social bonds, and for humans, it is called "love." Defining the term monogamy has been challenging. Obtaining a clear understanding of monogamy on a human level for categorizing human mating systems and social relationships between males and females would be a place to focus.

 Furthermore, the social organization gives advantages of shared parenting, protection of resources, and social support, but not always be sexually exclusive, so biology has narrowed monogamy definitions to social monogamy. In other words, one or both partners may not be sexually faithful but faithful to the relationship's economics, social support and shared parenting. Further research regarding social monogamy's social outcomes and the effects on the long-term relationship, from an evolutionary perspective, could validate how humans are distinctive in their emotional makeup in a physically intimate relationship. How would the biological function of being pair-bonded on a physical and social monogamy change future generations?

In the research regarding romantic relationships associated with drug addiction Fisher (2010), digging more profound in the accept of how we have accepted "love" and pair-bonding as an addiction may be reframed. Addiction holds a negative perception, and if the research can look into the notion that love is not an addiction but a healthy goal-oriented motivation. This may encourage a more positive perspective about human pair bonding and remove the social stigma associated that "love" is an addiction.

Further research on human evolution in courtship on a biological front and discover whether humans’ pair-bond and not just social monogamy, activate the A1aV respecters on an evolutionary level, and obtain "the whole package" in human relationships.

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