On Having and Holding
Willingness to protect from violence, independent of strength, guides partner choice
Michael Barlev et al.
Evolution and Human Behavior, November 2025
Abstract:
Ancestrally, physical violence from conspecifics was a recurrent adaptive problem. Did selection favor preferences for partners who are both strong (highly able) and willing to protect us from violence? Strength and willingness are interrelated, so dissociating their effects is necessary. Here we assessed both inferences and preferences. In 7 experiments (N = 4,508 U.S. adults recruited via MTurk), we systematically varied the willingness of a date or friend to physically protect you from an attack, compared to scenarios where you do not have this information. We also varied that person's strength. Discovering that a person is willing to protect greatly increased their attractiveness as a romantic partner or friend, regardless of their strength. This held for both women and men raters, and when evaluating both opposite- and same-sex dates and friends. In fact, partners who were willing to protect were attractive even if they tried to do so but failed, and even if you were harmed because of their failure. Discovering that a partner is unwilling to protect decreased their attractiveness, and was a deal-breaker for women evaluating a male date. Unwillingness decreased attractiveness more when the rater was a woman, when the target was a man, and when the target was being evaluated as a date versus friend. Women placed some importance on a male date's strength, but this was mostly due to inferences about his willingness to protect them. Surprisingly, we found only weak evidence that differences in strength, independent of willingness, increased the attractiveness of a partner.
Marriage, Cohabitation, and Separation: A Dynamic Approach to the Second Demographic Transition
Sean Elliott
University of Toronto Working Paper, November 2025
Abstract:
Across many advanced economies, the second demographic transition has reshaped household formation: marriage has declined, cohabitation has expanded, and both divorce and separation hazards have fallen. Using four decades of monthly U.S. demographic data, I first document three facts: (i) marriage has declined while cohabitation has risen, (ii) both unions have become more stable over time, and (iii) there are two inflection points — the mid-1990s, when substitution from marriage to cohabitation accelerated, and after the 2008 financial crisis, when remaining single became more common. Existing static or dynamic-stationary models cannot explain why fewer matches are formed even as those that do persist are more stable. To address this gap, I develop and estimate a dynamic, non-stationary marriage matching model with endogenous dissolution which allows for both marriage and cohabitation. The estimates show that rising match-formation costs outpaced surplus gains, reducing partnership formation, while marriage stability is driven by rising surplus and cohabitation stability by higher dissolution costs. Policy reforms in the 1990s coincide with the marriage-cohabitation substitution, and counterfactuals indicate that, coming out of the 2008 crisis, had house prices not risen so sharply, marriage formation would have been higher while cohabitation would have decreased.
Decreased sexual motivation during the human implantation window
James Roney et al.
Evolution and Human Behavior, November 2025
Abstract:
The implantation window denotes cycle days when the endometrium is receptive to an implanting blastocyst. Research supports increased risk of some types of sexually transmitted infections at this time due to local immunosuppression that facilitates the implantation process. This heightened infection risk may have selected for downregulation of sexual motivation within the mid-luteal phase days that comprise the human window of implantation. Here, using data from three large, daily diary studies (N > 2500 observations) among undergraduate participants, we tested whether measures of women's sexual motivation were dampened during the implantation window. Multi-level regression analyses on the combined sample demonstrated significant drops in multiple measures of sexual motivation within the estimated implantation window relative to other cycle regions. Furthermore, for most measures, sexual motivation was significantly lower during the implantation window relative to non-menstrual cycle days outside the fertile window, such that mid-luteal drops in desire and behavior were not statistical artifacts of elevations in sexual motivation during the fertile window. These findings are consistent with evolved, functional responses to temporal fluctuations in infection risk that may help to explain cycle phase shifts in human sexual motivation.
No Evidence That Women's Sociosexuality or Self-Perceived Mate Value Predict Their Preferences for Men's Face-Shape Masculinity
Pengting Lee et al.
Evolutionary Psychology, September 2025
Abstract:
Researchers have suggested that men with more masculine facial characteristics have stronger immune systems but are perceived to be less likely to invest resources in partners and offspring. How women resolve this putative trade-off between the costs and benefits of choosing a masculine mate have previously been reported to be associated with women's openness to uncommitted relationships (i.e., their sociosexuality) and self-perceived mate value. However, not all studies have reported these links and the methods used to assess masculinity preferences in studies reporting these patterns of results (forced-choice tests using stimuli in which masculinity was experimentally manipulated) have recently been criticized for having low ecological validity. Consequently, we tested whether sociosexuality or self-perceived mate value predicted women's masculinity preferences when masculinity preferences were assessed using ratings of individual natural (i.e., unmanipulated) male faces. Our analyses show no evidence that individual differences in women's sociosexuality or self-perceived mate value significantly predicted masculinity preferences. Thus, our results do not support the proposal that sociosexuality and/or self-perceived mate value are important sources of individual differences in women's preferences for male facial masculinity.
How Strangers Fall in Love in Games: Affective Infrastructures and Platformed Intimacy in China
Meng Wang
Social Media + Society, November 2025
Abstract:
In the platformized era, digital games have become key arenas for romantic connection, yet their role in shaping intimacy between strangers remains underexplored. This study examines how such relationships are initiated, developed, and evaluated in Honor of Kings, China's most popular multiplayer online battle arena (MOBA) game. Based on 25 in-depth interviews with young players, it addresses four questions: the stages of romantic intimacy formation, enabling digital affordances, reasons for choosing games over dating or social apps, and evaluations of game-based romantic relationships. Findings reveal a four-stage process — encounter, acquaintance, development, and establishment or termination. Conceptualizing games as affective infrastructures, the study shows how platform design structures and commodifies digital intimacy while enabling embodied, performative commitment. Comparative analysis with dating apps, social media, and Massively Multiplayer Online Role-Playing Games (MMORPGs) highlights the distinctiveness of fast-paced, interaction-intensive play in fostering embedded emotional commitment. It also uncovers players' tactical workarounds to reclaim autonomy from platforms. By theorizing intimacy as both enabled and contested within socio-technical systems, this research advances an infrastructural account of how love is imagined, enacted, and negotiated in contemporary digital culture.
Hot or Not? Implicit and Explicit Attitudes of Sexualized Profiles on Tinder
Morgan Ellithorpe, Laila Kunaish & Holly Wright
Cyberpsychology, Behavior, and Social Networking, November 2025, Pages 765-770
Abstract:
Research on dating applications relies heavily on explicitly measured evaluations of potential partners; however, the quick swiping mechanism of Tinder and other popular dating applications may rely on more spontaneous evaluations. We asked heterosexual U.S. undergraduates (n = 135) to rate opposite-gender Tinder profiles using both an implicit reaction time task and explicit self-report. Men had more positive implicit evaluations of sexualized profiles compared with women. Men also showed an implicitly measured preference for sexualized profiles over nonsexualized profiles, while women showed the opposite preference. However, the genders did not differ in evaluation of sexualized or nonsexualized profiles in explicitly measured evaluations. This study highlights the value of using implicit measures when conducting research on mobile dating.