Given the wealth of data presented in the target article on the attractiveness, formation, maintenance, and dissolution of romantic relationships between men and women, it is reasonable to expect the study’s results to reflect evolutionary adaptation mechanisms between the sexes. This is also readily possible if one understands “romantic relationships” primarily as those in which intimacy and thus sexuality play a special role. With the latter, biological reproduction comes into play and thus automatically natural selection, which has influenced human behavior for millennia (Wilson, Reference Wilson1978). In this way, the most important results of the analysis can be explained quite “naturally,” without having to refer to specific cultural influences:

1. 1. Men have a greater desire for “romance”: Human males should show a keen interest in maintaining the closest possible relationship with a woman for a longer period of time in order to increase their reproductive success. Women, on the other hand, due to their strong commitment to their offspring in the form of long pregnancy, lactation, and maternal care, can afford the “luxury” of being selective in their choice of partner and not always accepting the very first person they meet (Thornhill & Gangestad, Reference Thornhill and Gangestad2008).

2. 2. Men benefit more from a romantic relationship: since – in keeping with Schiller’s famous saying: “Who a lovely wife attaineth, join us in his jubilee!” – the successful establishment of a romantic relationship with a woman eliminates the stress for the man of having to establish one in the first place, this clearly results in a significantly improved physical and mental condition of the “victorious” man, with long-term positive consequences even for his mortality (Ben-Shlomo et al., Reference Ben-Shlomo, Smith, Shipley and Marmot1993).

3. 3. Men are more interested in maintaining a romantic relationship: since the probability of producing offspring increases with the duration of a relationship, men should be more interested in continuing it than women, whose reproductive chances are generally higher in the first place (Wilder, Mobasher, & Hammer, Reference Wilder, Mobasher and Hammer2004).

4. 4. Men suffer more from the dissolution of a romantic relationship: since a man is exposed to increased competition with other men after the dissolution of a relationship, he suffers more than a woman who – at least while she is still young – can expect with greater probability to find a new partner or at least emotional support in her circle of close friends and relatives (Burleson, Reference Burleson2003).

However, to better understand the special nature of human pair bonding, one must distance oneself somewhat from the widespread sociobiological cliché that – as given in most mammalian species (e.g., ungulates) – in humans too, only the female sex is the investing sex, and the male, due to its low propensity to invest, is thus the selected sex subject to “female choice” (Trivers, Reference Trivers1972). This may be true to a certain extent, because otherwise “quickies” would not be so popular with men, but it does not affect the fundamental desire of the vast majority of men to establish a family based on a lasting romantic relationship. Furthermore, human males like to “fraternize” with other males to gain greater control over their female partners – similar to what male lions (Packer & Pusey, Reference Packer and Pusey1982) and chimpanzees (de Waal, Reference De Waal1982) do. In this way, what were once grumpy loners, such as the tree-dwelling male orangutan still is today, evolved into highly sociable group creatures who, over time, not only succeeded in compensating for the comparatively high investment of women in their offspring by allocating appropriate resources (food, shelter, protection), but increasingly even surpassed them, with particularly “heroic” men willing to sacrifice their lives for the survival of clan and family (e.g. in battles against enemies).

In the long term, this has led to the fact that, until recently, in most human cultures, almost everything women had to do or not do was determined by rules established by men. Human men have achieved this evolutionary coup over the last 6–7 million years, that is, since their split from the common ancestor with the chimpanzee, by making women more dependent on their benevolence precisely through their increased commitment to their well-being. One can even assume that without men’s pronounced “protective instinct,” human evolution would probably never have occurred, because the transition from life in the secure forest to the bipedal settlement of the open savannah was – as we now know – anything but an evolutionary walk in the park (Hart & Sussman, Reference Hart and Sussman2009).

Whatever the ultimate concrete reason may have been, be it the need for increased cooperation (Bromhall, Reference Bromhall2003) or the invention of effective weapons for defense against large predators (e.g., sticks, wooden clubs; Hrncir, Reference Hrncir2023), or a combination of both, the permanent union of men to protect “their” women worked and gradually began to replace the original biological dominance of the female. This even went so far that, until recently, in many cultures, women’s sexual lives were meticulously regulated (Shrock, Reference Shrock1984; Barkan, Reference Barkan2014), from strict assignment to a specific man to the safeguarding of paternity through sometimes rigorous codes of conduct (e.g., the death penalty for infidelity) and health-endangering interventions (e.g., female circumcision).

All of this only changed with the beginning of the modern era, when a kind of abstract and, for the first time, non-religious overprotector called “the State” emerged, which increasingly assisted women with existential problems, independent of their partners. This, however, made it increasingly difficult for caring men to be seen as reliable partners in the eyes of their wives, as the community as a whole now appeared as an overpowering competitor to men. As a consequence, the divorce rate in Western countries rose, and with it the number of men who suddenly found themselves on their own because, unlike women, they could not rely on a comparably solid, socio-emotional safety net of close friends and relatives. The fact that men, due to their stronger tendency to romanticize relationships while simultaneously facing the risk of social isolation and the resulting potential for harm to themselves and others, now also need institutional support through special “men’s support groups” is therefore a relatively recent development.