Assortative mating in personality among heterosexual and male homosexual couples from Brazil and the Czech Republic

The Pattern of Physique Preferences on Gay Dating App "Blued" in China: A Multiple Group Latent Class Analysis

Previous studies have indicated homogamy in partner preferences among gay and bisexual men. Individuals on Blued (the most popular gay dating app in China) could identify their body type and preferred physiques according to six categories: monkey (thin gay men), average, muscularity, bear (heavy and hairy gay men), baboon (smaller than bears), and pig (plumper than bears). This study examined patterns of physique preferences across body types as well as sexual self-labels (tops, bottoms, versatiles, and others). In total, 188,716 Blued profiles (Mage = 31.1, SD = 7.1) were obtained. Multiple group latent class analysis was used to examine the patterns of physique preferences across the body type groups. The results revealed seven classes of physique preference. The four common physique preferences shared by all body type groups were "like averages," "like monkeys," "like muscularity," and "like bears." Individuals with a monkey or average body type exhibited a specific pattern of physique preference: "dislike bears." The two physique preferences specific to gay bear men were "like averages and muscularity," and "dislike monkeys." The highest preference for each physique was observed among individuals of the same body type. Furthermore, tops were more likely to have a muscular body and prefer a monkey physique, whereas bottoms were more likely to have a monkey body and prefer a muscular physique. These findings indicate body type-specific physique preferences based on an individual's own body type and sexual self-label identification, thus partially supporting the concept of homogamy in the physique preferences of gay men.

What Do Different People Look for in a Partner? Effects of Sex, Sexual Orientation, and Mating Strategies on Partner Preferences

Partner preferences are an important differential in relationship formation and evolutionary fitness, and vary according to individual, ecological, and social factors. In this study, we evaluated the variation in preference for intelligence, kindness, physical attractiveness, health, and socioeconomic level among individuals of different sexes and sexual orientations in a Brazilian sample. We analyzed the preference scores of 778 heterosexual, bisexual, and homosexual men and women in three budgeted mate design tasks (low vs. medium vs. high budget) and their association with sociosexuality, attachment styles, homogamy, and willingness to engage in short- and long-term relationships. Results indicated a global trait preference order, with intelligence ranking first, followed by kindness, physical attractiveness, health, and lastly by socioeconomic status. Typical sex differences were observed mostly within the heterosexual group, and specific combinations of sex and sexual orientation were linked to variation in preference for physical attractiveness, kindness, and socioeconomic status. We also found unique associations of the other variables with partner preferences and with willingness to engage in short- or long-term relationships. By exploring the partner preferences of non-heterosexual individuals from a Latin American country, an underrepresented group in evolutionary psychology research, our results help understand the universal and specific factors that guide partner preferences and human sexual behavior.

Preference for Self-Resembling Male Faces in Gay Men in China

Self-resemblance refers to couples with similar characteristics, also known as homogamy or positive assortative mating. Previous studies have indicated that heterosexual men and women prefer partners with similar facial features. In this study, we examined whether Chinese gay men preferred self-resemblance to faces. The participants (N = 70) completed a personal information questionnaire and preference selection task involving 10 pairs of self-resembling/control male faces. Ten pairs of self-resembling/control male faces of each participant were also rated by another gay man. The results revealed that the proportion of the participants who chose self-resembling faces was significantly higher than that of the control faces. However, the preference for "self-resembling" and control faces by other-rating was not significantly different. These findings indicate homogeneity in facial preferences among gay men.

Consistency of Eye Coloration Across Different Relationship Partners

Studies have indicated that people are attracted to partners who resemble themselves or their parents, in terms of physical traits including eye color. We might anticipate this inclination to be relatively stable, giving rise to a sequential selection of similar partners who then represent an individual's "type". We tested this idea by examining whether people's sequential partners resembled each other at the level of eye color. We gathered details of the eye colors of the partners of participants (N = 579) across their adult romantic history (N = 3250 relationships), in three samples, comprising two samples which made use of self-reports from predominantly UK-based participants, and one which made use of publicly available information about celebrity relationship histories. Recorded partner eye colors comprised black (N = 39 partners), dark brown (N = 884), light brown (N = 393), hazel (N = 224), blue (N = 936), blue green (N = 245), grey (N = 34), and green (N = 229). We calculated the proportion of identical eye colors within each participant's relationship history, and compared that to 100,000 random permutations of our dataset, using t-tests to investigate if the eye color of partners across an individual's relationship history was biased relative to chance (i.e., if there was greater consistency, represented by higher calculated proportions of identical eye colors, in the original dataset than in the permutations). To account for possible eye color reporting errors and ethnic group matching, we ran the analyses restricted to White participants and to high-confidence eye color data; we then ran the analyses again in relation to the complete dataset. We found some limited evidence for some consistency of eye color across people's relationship histories in some of the samples only when using the complete dataset. We discuss the issues of small effect sizes, partner-report bias, and ethnic group matching in investigating partner consistency across time.

Parental Investment Is Biased toward Children Named for Their Fathers

Namesaking (naming a child after a parent or other relative) can be viewed as a mechanism to increase perceived parent-child similarity and, consequently, parental investment. Male and, to a lesser extent, firstborn children are more frequently namesakes than female and later-born children, respectively. However, a direct link between namesaking and parental investment has not been examined. In the present study, 632 participants (98 men and 534 women) from Central Europe indicated their first name, sex, birth order, number of siblings, sexual orientation, socioeconomic status, paternal and maternal first names, as well as relationship quality with, and time and financial investment they received from, both parents during childhood. Mixed-effects models revealed associations between namesaking and parental investment. However, the effect of namesaking often appeared significant only in interaction with specific predictors, such as sex and primogeniture. It suggests instead that namesaking has an additive effect-it enhances the effect of biological factors on parental investment. In general, we found evidence for the bias in parental investment linked to name similarity among both parents, and support for the hypothesis that namesaking serves as a mechanism to increase paternity confidence and, thus, paternal investment. The effect of namesaking influences only certain types of parental investment-namely, those at the level of relationship quality. In addition, nonheterosexual orientation was the strongest negative predictor of paternal investment. Our study extends the research on parental investment by showing that cultural mechanisms, such as namesaking, can also exert some influence on parental rearing behavior.

COVID-19 Pandemic on Fire: Evolved Propensities for Nocturnal Activities as a Liability Against Epidemiological Control

Humans have been using fire for hundreds of millennia, creating an ancestral expansion toward the nocturnal niche. The new adaptive challenges faced at night were recurrent enough to amplify existing psychological variation in our species. Night-time is dangerous and mysterious, so it selects for individuals with higher tendencies for paranoia, risk-taking, and sociability (because of security in numbers). During night-time, individuals are generally tired and show decreased self-control and increased impulsive behaviors. The lower visibility during night-time favors the partial concealment of identity and opens more opportunities for disinhibition of self-interested behaviors. Indeed, individuals with an evening-oriented chronotype are more paranoid, risk-taking, extraverted, impulsive, promiscuous, and have higher antisocial personality traits. However, under some circumstances, such as respiratory pandemics, the psychobehavioral traits favored by the nocturnal niche might be counter-productive, increasing contagion rates of a disease that can evade the behavioral immune system because its disease cues are often nonexistent or mild. The eveningness epidemiological liability hypothesis presented here suggests that during the COVID-19 pandemic, the evening-oriented psychobehavioral profile can have collectively harmful consequences: there is a clash of core tendencies between the nocturnal chronotype and the recent viral transmission-mitigating safety guidelines and rules. The pandemic safety protocols disrupt much normal social activity, particularly at night when making new social contacts is desired. The SARS-CoV-2 virus is contagious even in presymptomatic and asymptomatic individuals, which enables it to mostly evade our evolved contagious disease avoidance mechanisms. A growing body of research has indirectly shown that individual traits interfering with social distancing and anti-contagion measures are related to those of the nocturnal chronotype. Indeed, some of the social contexts that have been identified as superspreading events occur at night, such as in restaurants, bars, and nightclubs. Furthermore, nocturnal environmental conditions favor the survival of the SARS-CoV-2 virus much longer than daytime conditions. We compare the eveningness epidemiological liability hypothesis with other factors related to non-compliance with pandemic safety protocols, namely sex, age, and life history. Although there is not yet a direct link between the nocturnal chronotype and non-compliance with pandemic safety protocols, security measures and future empirical research should take this crucial evolutionary mismatch and adaptive metaproblem into account, and focus on how to avoid nocturnal individuals becoming superspreaders, offering secure alternatives for nocturnal social activities.

Preference for Male Facial Masculinity as a Function of Mental Rotation Ability in Gay and Bisexual Men, but Not in Heterosexual Men and Women in China

This study examined the association between mental rotation ability and facial masculinity preference in gay and bisexual men in China. The participants (436 gay/bisexual men, 132 heterosexual men, and 254 heterosexual women) completed an online Shepard and Metzler-type mental rotation task and a forced-choice preference task of 10 pairs of masculinized/feminized male faces. The results revealed that mental rotation ability was significantly associated with preference for masculinized faces in both gay and bisexual men. There were no significant correlations between mental rotation ability and facial masculinity preference in both heterosexual men and women. The findings imply homogamy in partner preference in gay and bisexual men in terms of masculinity.

Mate Preferences in Three Muslim-Majority Countries: Sex Differences and Personality Correlates

Cross-cultural research on long-term mate preferences in Muslim-majority countries is scarce. The research described here aims to examine the KASER (kindness/dependability, attractiveness/sexuality, status/resources, education/intelligence, and religiosity/chastity) model of mate preferences in Iran, Pakistan, and Turkey ( N = 1,089). We examined structural validity, measurement invariance between men and women, sex differences, cultural differences, and Big Five personality correlates of these dimensions of mate preferences. Findings supported preregistered hypotheses regarding sex differences in mate preferences. Multilevel models suggested that the magnitude of sex differences was invariant across cultures. Personality correlates of mate preferences varied across cultures, but agreeableness consistently predicted the preference for kind and dependable partners across cultures. In sum, sex differences in mate preferences within and across three Muslim-majority countries described here replicate previous findings, but evidence for personality correlates of mate preferences is mixed, variable across cultures, and in need of further examination in non-Western samples.