No association between developmental instability as a general measure of stress and 2D:4D digit ratios in a non-western sample.

OBJECTIVE: Random deviation from perfect symmetry of organisms is defined as fluctuating asymmetry. Fluctuating asymmetry is widely considered to be a marker of developmental instability, developmental noise and phenotypic quality at the population level. In this study, we investigated hypothesized relationship between 2D:4D digit ratios as a proxy measure of prenatal sex hormones and developmental instability levels in young adult humans. MATERIALS AND METHODS: In the study, seven bilateral traits were measured for fluctuating asymmetry, as well as second and fourth digit lengths on both hands of 185 individuals, 87 men (mean age: 22.42 ± 3.37) and 97 women (mean age: 22.88 ± 3.87). The second digit length was divided by the fourth digit length and the resulting value was used as the digit ratio (2D:4D). Composite fluctuating asymmetry was calculated using five bilateral traits displaying fluctuating asymmetry. RESULTS: Only the right hand 2D:4D ratio is lower in men than in women. However, this difference disappears when the effect of digit lengths is controlled. Composite fluctuating asymmetry results reveal that men are more asymmetrical than women. There was no significant relationship between digit ratios and composite fluctuating asymmetry. CONCLUSION: In this study, the 2D:4D digit ratios appear to be influenced (at least in humans) by different digit lengths. This study also confirms previous studies that digit ratios as a proxy measure of exposure to either high testosterone or estrogen levels during early development does not appear to affect levels of developmental instability.

Sex differences in human mate preferences vary across sex ratios.

A wide range of literature connects sex ratio and mating behaviours in non-human animals. However, research examining sex ratio and human mating is limited in scope. Prior work has examined the relationship between sex ratio and desire for short-term, uncommitted mating as well as outcomes such as marriage and divorce rates. Less empirical attention has been directed towards the relationship between sex ratio and mate preferences, despite the importance of mate preferences in the human mating literature. To address this gap, we examined sex ratio's relationship to the variation in preferences for attractiveness, resources, kindness, intelligence and health in a long-term mate across 45 countries (n = 14 487). We predicted that mate preferences would vary according to relative power of choice on the mating market, with increased power derived from having relatively few competitors and numerous potential mates. We found that each sex tended to report more demanding preferences for attractiveness and resources where the opposite sex was abundant, compared to where the opposite sex was scarce. This pattern dovetails with those found for mating strategies in humans and mate preferences across species, highlighting the importance of sex ratio for understanding variation in human mate preferences.

Sex Differences in Mate Preferences Across 45 Countries: A Large-Scale Replication.

Considerable research has examined human mate preferences across cultures, finding universal sex differences in preferences for attractiveness and resources as well as sources of systematic cultural variation. Two competing perspectives-an evolutionary psychological perspective and a biosocial role perspective-offer alternative explanations for these findings. However, the original data on which each perspective relies are decades old, and the literature is fraught with conflicting methods, analyses, results, and conclusions. Using a new 45-country sample (N = 14,399), we attempted to replicate classic studies and test both the evolutionary and biosocial role perspectives. Support for universal sex differences in preferences remains robust: Men, more than women, prefer attractive, young mates, and women, more than men, prefer older mates with financial prospects. Cross-culturally, both sexes have mates closer to their own ages as gender equality increases. Beyond age of partner, neither pathogen prevalence nor gender equality robustly predicted sex differences or preferences across countries.

Relationship between parental consanguinity and digit ratios (2D:4D) among Turkish newborns in Sivas.

OBJECTIVES: The aim of this study was to investigate the effects of parental consanguinity on the 2D:4D digit ratio of newborn infants, whose parents were the first cousins. METHODS: The study included healthy and full-term newborn infants, delivered in a hospital, at the gestational ages from 37 to 41 weeks. A total of 225 newborns and their parents were included in the study. Of these 225 newborns; 100 were inbred and 125 were outbred infants. We used a Vernier caliper to measure the length of the second and fourth digits of the newborns (accuracy: 0.01 mm). RESULTS: Controlling for education and number of pregnancies, male newborns had lower digit ratios than female newborns, for both left and right hands. There were, moreover, differences between inbred and outbred samples. We determined that inbreeding was related to a reduction in the digit ratios regardless of the side of the hand and the sex of the infant, showing a consistent tendency to appear more masculine. Interaction between marriage type*sex was highly significant. CONCLUSIONS: Parental consanguinity appears to cause fetal masculinization of digit ratios by increasing fetal stress among Turkish newborns.

Prenatal exposure to oestrogens estimated by digit ratio (2d/4d) and breast size in young nulliparous women.

Digit ratio (2d/4d) in humans is commonly used as a proxy for the exposure to oestrogens and androgens in prenatal life. Masculinisation/feminisation in adults may be also related to digit ratio and therefore to the oestrogen/androgen ratio in prenatal life. It has been shown, for instance, that Waist-to-Hip ratio (WHR) and the amount and distribution of body fat are related to digit ratio in women. A species-specific, sexually dimorphic morphological trait in humans is also a pair of permanent breasts that develop during puberty, under the influence of oestrogens. Here we test if prenatal exposure to oestrogens (in relation to androgens), measured by digit ratio, may also be related to breast size in young, nulliparous women. 133 Turkish students (mean age 22.2) were measured. Breast size was calculated as the difference between breast and under-breast circumferences. We found that when controlling for body mass index (BMI), both right and left digit ratios correlate positively with breast size. This relationship is stronger for the digit ratio of the right hand, which confirms that this side is a better measure of sex differences. Thus, higher exposure to oestrogens in prenatal life is related with stronger expression of a sexually dimorphic trait, such as breast size, in adult women.

Modernization, collectivism, and gender equality predict love experiences in 45 countries.

Recent cross-cultural and neuro-hormonal investigations have suggested that love is a near universal phenomenon that has a biological background. Therefore, the remaining important question is not whether love exists worldwide but which cultural, social, or environmental factors influence experiences and expressions of love. In the present study, we explored whether countries' modernization indexes are related to love experiences measured by three subscales (passion, intimacy, commitment) of the Triangular Love Scale. Analyzing data from 9474 individuals from 45 countries, we tested for relationships with country-level predictors, namely, modernization proxies (i.e., Human Development Index, World Modernization Index, Gender Inequality Index), collectivism, and average annual temperatures. We found that mean levels of love (especially intimacy) were higher in countries with higher modernization proxies, collectivism, and average annual temperatures. In conclusion, our results grant some support to the hypothesis that modernization processes might influence love experiences.

The negative effect of heavy work life during adolescence on height development of young males.

The aim of this study was to determine the physical development level of post-adolescent automotive repair workers who had been employed in heavy work during adolescence, a critical developmental period. Young workers (Group 1, N = 106, Mean age = 18.33, SD = 0.65) employed an average of 6 years in workshops in the capital of Turkey, Ankara. For the control group, two groups of the same age but having a difference in terms of socioeconomic status were chosen. The first one of these was comprised of individuals who had the same socioeconomic status as the laborers (Group 2, N = 106, Mean age = 18.33, SD = 0.65) but were not laborers. The second control group was composed of individuals from the higher socioeconomic levels of society (Group 3, N = 100, Mean Age = 18.45 SD = 0.63). Weight, height and measures were taken from the individuals and the body mass index (kg/m2) was calculated. The results of the analysis show that, although all the variables of the labor group were lower than Group 2, the difference is only significant for the height variable (p < 0.05). These findings reveal that, having completed a critical developmental period such as adolescence after being employed in heavy work, the automotive repair youngsters are prone to chronic developmental retardation.

Factors Associated With Highest Symptoms of Anxiety During COVID-19: Cross-Cultural Study of 23 Countries.

The COVID-19 restrictions have impacted people's lifestyles in all spheres (social, psychological, political, economic, and others). This study explored which factors affected the level of anxiety during the time of the first wave of COVID-19 and subsequent quarantine in a substantial proportion of 23 countries, included in this study. The data was collected from May to August 2020 (5 June 2020). The sample included 15,375 participants from 23 countries: (seven from Europe: Belarus, Bulgaria, Croatia, Hungary, Italy, Romania, Russia; 11 from West, South and Southeast Asia: Armenia, India, Indonesia, Iran, Iraq, Jordan, Malaysia, Pakistan, Saudi Arabia, Thailand, Turkey; two African: Nigeria and Tanzania; and three from North, South, and Central America: Brazil, Canada, United States). Level of anxiety was measured by means of the 7-item Generalized Anxiety Disorder Scale (GAD-7) and the 20-item first part of The State-Trait Anxiety Inventory (STAI)-State Anxiety Inventory (SAI). Respondents were also asked about their personal experiences with COVID-19, attitudes toward measures introduced by governments, changes in attitudes toward migrants during a pandemic, family income, isolation conditions, etc. The factor analysis revealed that four factors explained 45.08% of variance in increase of anxiety, and these components were interpreted as follows: (1) personal awareness of the threat of COVID-19, (2) personal reaction toward officially undertaken measures and attitudes to foreigners, (3) personal trust in official sources, (4) personal experience with COVID-19. Three out of four factors demonstrated strong associations with both scales of anxiety: high level of anxiety was significantly correlated with high level of personal awareness of the threat of COVID-19, low level of personal reaction toward officially undertaken measures and attitudes to foreigners, and high level of presence of personal experience with COVID-19. Our study revealed significant main effects of sex, country, and all four factors on the level of anxiety. It was demonstrated that countries with higher levels of anxiety assessed the real danger of a pandemic as higher, and had more personal experience with COVID-19. Respondents who trusted the government demonstrated lower levels of anxiety. Finally, foreigners were perceived as the cause of epidemic spread.

Relationship between shortness of final body height and fluctuating asymmetry in Turkish young males.

BACKGROUND: Body height is a versatile bio-indicator in that it reflects the quality of physical development. Fluctuating asymmetry, on the other hand, refers to small random deviations from perfect symmetry in bilaterally paired structures and is believed to reflect the ability of an organism to cope with genetic and environmental stresses during its development. AIM: This study sought to investigate the relationship between body height and fluctuating asymmetry in young adult males who display different height-development structures. SUBJECT AND METHODS: Height and eight bilateral non-facial traits were measured in a sample of 320 young male individuals from different socioeconomic backgrounds who display differences in height. Z-scores of each individual were calculated based on the age-range values indicated in the Center for Disease Control's (CDC) 2000 growth data of the US. RESULTS: The five measurements demonstrating fluctuating asymmetry indicate that there is a significant increase in fluctuating asymmetry that parallels the decrease in body height. Developmental stability increases with the increasing body height. CONCLUSION: This finding implies that the stresses causing slower growth in body height might have negative effects also on fluctuating asymmetry.

Universality of the Triangular Theory of Love: Adaptation and Psychometric Properties of the Triangular Love Scale in 25 Countries.

The Triangular Theory of Love (measured with Sternberg's Triangular Love Scale - STLS) is a prominent theoretical concept in empirical research on love. To expand the culturally homogeneous body of previous psychometric research regarding the STLS, we conducted a large-scale cross-cultural study with the use of this scale. In total, we examined more than 11,000 respondents, but as a result of applied exclusion criteria, the final analyses were based on a sample of 7332 participants from 25 countries (from all inhabited continents). We tested configural invariance, metric invariance, and scalar invariance, all of which confirmed the cultural universality of the theoretical construct of love analyzed in our study. We also observed that levels of love components differ depending on relationship duration, following the dynamics suggested in the Triangular Theory of Love. Supplementary files with all our data, including results on love intensity across different countries along with STLS versions adapted in a few dozen languages, will further enable more extensive research on the Triangular Theory of Love.

Affective Interpersonal Touch in Close Relationships: A Cross-Cultural Perspective.

Interpersonal touch behavior differs across cultures, yet no study to date has systematically tested for cultural variation in affective touch, nor examined the factors that might account for this variability. Here, over 14,000 individuals from 45 countries were asked whether they embraced, stroked, kissed, or hugged their partner, friends, and youngest child during the week preceding the study. We then examined a range of hypothesized individual-level factors (sex, age, parasitic history, conservatism, religiosity, and preferred interpersonal distance) and cultural-level factors (regional temperature, parasite stress, regional conservatism, collectivism, and religiosity) in predicting these affective-touching behaviors. Our results indicate that affective touch was most prevalent in relationships with partners and children, and its diversity was relatively higher in warmer, less conservative, and religious countries, and among younger, female, and liberal people. This research allows for a broad and integrated view of the bases of cross-cultural variability in affective touch.

Contrasting Computational Models of Mate Preference Integration Across 45 Countries.

Humans express a wide array of ideal mate preferences. Around the world, people desire romantic partners who are intelligent, healthy, kind, physically attractive, wealthy, and more. In order for these ideal preferences to guide the choice of actual romantic partners, human mating psychology must possess a means to integrate information across these many preference dimensions into summaries of the overall mate value of their potential mates. Here we explore the computational design of this mate preference integration process using a large sample of n = 14,487 people from 45 countries around the world. We combine this large cross-cultural sample with agent-based models to compare eight hypothesized models of human mating markets. Across cultures, people higher in mate value appear to experience greater power of choice on the mating market in that they set higher ideal standards, better fulfill their preferences in choice, and pair with higher mate value partners. Furthermore, we find that this cross-culturally universal pattern of mate choice is most consistent with a Euclidean model of mate preference integration.