Nuanced HEXACO: A Meta-Analysis of HEXACO Cross-Rater Agreement, Heritability, and Rank-Order Stability.

Most Five-Factor Model (FFM) questionnaire items contain unique variance that is partly heritable, stable, and consensually observable, demonstrates consistent associations with age and sex, and predicts life outcomes beyond higher order factors. Extending these findings to the HEXACO model, we meta-analyzed single-item cross-rater agreement, heritability, and 2-year stability using samples from six countries. We analyzed raw item scores and their residual variance and adjusted the estimates for measurement unreliability. The median cross-rater agreement, heritability, and stability estimates were, respectively, .30, .30, and .57, for raw items and .10, .16, and .39, for item residuals. Adjusted for reliability, the respective medians were .46 and .25 for cross-rater agreement, .46 and .39 for heritability, and .87 and .94 for stability. These results are strikingly consistent with FFM-based findings, providing nondismissible evidence that single items index a partly unique level of the trait hierarchy-personality nuances-with trait properties comparable to those of higher-order traits.

High-intensity interval training (HIIT) and slow breathing interventions alleviate premature ejaculation (PE) symptoms.

Background: Physical exercise may alleviate premature ejaculation symptoms, a prevalent male sexual dysfunction linked to a series of negative outcomes for men and their partners. Objective: We investigated the effectiveness of high-intensity interval training (HIIT) and slow breathing interventions on premature ejaculation symptoms and their relation to autonomic activity and attention regulation. Method: Chinese adult men (N = 76, M = 21.89, SD = 3.32) with premature ejaculation completed one of the two-week interventions in their homes or as participants in a normal breathing control group; they reported their age, height, weight, physical activity level, premature ejaculation symptoms, and attention regulation. In the HIIT group, 26 participants engaged in a 7-minute HIIT each day. In the slow breathing group, 25 participants performed 7-minute slow breathing exercises per day while the 25 participants in the normal breathing group similarly performed normal breathing exercises. All participants measured their heart rate once before and five times (with one-minute intervals) after the intervention. When participants had penile-vaginal sex with their partners, they measured their heart rate once after ejaculation. Results: Time × Intervention interaction was significant with lower levels of premature ejaculation symptoms on Days 12, 13, and 14 in the HIIT group (M ± SD = 16.19 ± 3.45, 15.96 ± 3.43, and 15.15 ± 3.62) compared to the normal breathing group (M ± SD = 17.68 ± 3.06, 17.68 ± 3.15, and 17.44 ± 3.25). Higher levels of attention regulation were associated with fewer premature ejaculation symptoms. We also found that a larger increase in heart rate from resting to after sex was associated with fewer premature ejaculation symptoms. Conclusion: Compared to the control group, the efficacy of two weeks of HIIT exercise in mitigating PE symptoms suggests its potential as a novel treatment for PE.

Links between Aggressive Sexual Fantasies and Sexual Coercion: A Replication and Extension of a Multifactorial Model.

Current research indicates that aggressive sexual fantasies (ASF) are related to sexual aggression, above and beyond other risk factors for this behavior. There have, however, rarely been explicitly considered in multifactor models aiming to explain sexual aggression. One exception is the multifactorial Revised Confluence Model of Sexual Aggression that was replicated in two samples of male individuals who were convicted of sexual offenses and a small sample of men from the general population and evidenced a high relevance of ASF, respectively. There were, however, no further attempts to replicate the model in larger samples from the general population. We, therefore, used a subsample from the Finnish Genetics of Sexuality and Aggression project including 3269 men (age: M = 26.17 years, SD = 4.76) to do so. Cross-sectional latent structural equation models corroborated previous research and the assumption that ASF are a central component in multifactor models that aim to explain sexual aggression: ASF and antisocial behavior/aggression were equally important associates of sexual coercion when also considering adverse childhood experiences, hypersexuality, and callous-unemotional traits. Additionally, ASF mediated the links between hypersexuality, callous-unemotional traits, as well as childhood sexual abuse and sexual coercion. These links held stable when entering further risk factors, that is, distorted perceptions, rape-supportive attitudes, and violent pornography consumption into the model. Contrasting assumptions, alcohol consumption and antisocial behavior/aggression did not interact. These results illustrate the potential importance of ASF for sexual aggression. They indicate that ASF require consideration by research on sexual aggression as well as in the treatment and risk assessment of sexual perpetrators.

A 2-week high-intensity interval training intervention improves ejaculation control among men with premature ejaculation.

BACKGROUND: Premature ejaculation (PE), which leads to substantial distress in men and their partners, is a common male sexual dysfunction worldwide. However, there is still a lack of effective treatments without side effects. OBJECTIVES: We investigated the effect of high-intensity interval training (HIIT) on PE symptoms. MATERIALS AND METHODS: We recruited 92 Chinese men aged 18-36 to complete the experiment. There were 22 (13 in the control group; 9 in the HIIT group) men diagnosed with PE and 70 (41 in the control group; 29 in the HIIT group) men with normal ejaculatory function. In the HIIT group, participants completed HIIT exercises every morning for 14 days. Participants also completed surveys inquiring about demographic information, erectile function, PE symptoms, body image (including sexual body image), physical activity, and sexual desire. The heart rate was measured before and after each HIIT. In the control group, participants were instructed not to do HIIT, but other procedures were the same as in the HIIT group. RESULTS: Results indicated that the HIIT intervention alleviated PE symptoms in men with PE. In addition, in the HIIT group, men with PE who had a higher heart-rate increase during the HIIT intervention reported the greatest overall decrements in PE symptoms. In men with normal ejaculatory function, HIIT did not decrease PE symptoms. In addition, increments in the heart rate during the intervention were associated with more pronounced PE symptoms post-intervention in this group. Analyses of secondary outcome measures suggested that the HIIT intervention improved general and sexual body image satisfaction of men with PE compared to before the intervention. DISCUSSION AND CONCLUSION: In summary, HIIT intervention may reduce PE symptoms in men with PE. The heart-rate increase during the intervention may be a key factor influencing the effect of the HIIT intervention on PE symptoms.

Genetic and Environmental Influences on Sexual Orientation: Moderation by Childhood Gender Nonconformity and Early-Life Adversity.

Existing evidence indicates genetic and non-genetic influences on sexual orientation; however, the possibility of gene-environment interplay has not been previously formally tested despite theories indicating this. Using a Finnish twin cohort, this study investigated whether childhood gender nonconformity and early-life adversities independently moderated individual differences in sexual orientation and childhood gender nonconformity, the relationship between them, and the etiological bases of the proposed moderation effects. Sexual orientation, childhood gender nonconformity, and early-life adversities were assessed using standard questionnaires. Structural equation twin model fitting was carried out using OpenMx. Childhood gender nonconformity was significantly associated with reduced phenotypic variance in sexual orientation (ß = - 0.14, 95% CI - 0.27, - 0.01). A breakdown of the underlying influences of this moderation effect showed that this was mostly due to moderation of individual-specific environmental influences which significantly decreased as childhood gender nonconformity increased (ßE = - 0.38; 95% CI - 0.52, - 0.001) while additive genetic influences were not significantly moderated (ßA = 0.05; 95% CI - 0.30, 0.27). We also observed that the relationship between sexual orientation and childhood gender nonconformity was stronger at higher levels of childhood gender nonconformity (ß = 0.10, 95% CI 0.05, 0.14); however, significance of the underlying genetic and environmental influences on this relationship could not be established in this sample. The findings indicate that beyond a correlation of their genetic and individual-specific environmental influences, childhood gender nonconformity is further significantly associated with reduced individual-specific influences on sexual orientation.

Endogenous Opioid Release After Orgasm in Man: A Combined PET/Functional MRI Study.

The endogenous µ-opioid receptor (MOR) system plays a key role in the mammalian reward circuit. Human and animal experiments suggest the involvement of MORs in human sexual pleasure, yet this hypothesis currently lacks in vivo support. Methods: We used PET with the radioligand [11C]carfentanil, which has high affinity for MORs, to quantify endogenous opioid release after orgasm in man. Participants were scanned once immediately after orgasm and once in a baseline state. Hemodynamic activity was measured with functional MRI during penile stimulation. Results: The PET data revealed significant opioid release in the hippocampus. Hemodynamic activity in the somatosensory and motor cortices and in the hippocampus and thalamus increased during penile stimulation, and thalamic activation was linearly dependent on self-reported sexual arousal. Conclusion: Our data show that endogenous opioidergic activation in the medial temporal lobe is centrally involved in sexual arousal, and this circuit may be implicated in orgasmic disorders.

Actual and Desired Masturbation Frequency, Sexual Distress, and Their Correlates.

We investigated the prevalence of problematic masturbation using different criteria. We also investigated if masturbation-related distress was associated with sexual abuse history, family attitudes towards sexuality during childhood, and depression and anxiety symptoms. Here, 12,271 Finnish men and women completed a survey reporting masturbation frequency, desired masturbation frequency, sexual distress, childhood sexual abuse, sex-positive family background, as well as depression and anxiety symptoms. Among both sexes, those whose masturbation frequency did not match with desired frequency experienced more sexual distress. Different conceptualizations of problematic masturbation resulted in different proportions of individuals categorized as having it (i.e., 8.3% of men and 2.7% of women experienced self-perceived problematic masturbation, that is masturbating more than they desired and experiencing sexual distress; 2% of men and 0.6% of women masturbated more frequently than average and meanwhile experienced self-perceived problematic masturbation; 6.3% of men and 2.1% of women masturbated less frequently than average but still experienced self-perceived problematic masturbation). Moreover, among both sexes, self-perceived problematic masturbation was positively associated with childhood sexual abuse, depression, and anxiety, while negatively associated with a sex-positive family background. Our results point to the complexity of defining problematic masturbation. Causes of sexual distress related to masturbation need to be carefully examined case by case to choose an appropriate clinical approach.

No evidence that sociosexual orientation moderates effects of conception probability on women's preferences for male facial masculinity.

Although many researchers have proposed that women will show stronger preferences for male facial masculinity when conception probability is high, empirical tests of this hypothesis have produced mixed results. One possible explanation for these inconsistent findings is that effects of conception probability on women's preferences for facial masculinity are moderated by additional factors not typically considered in these empirical tests. One such potential moderator is individual differences in women's openness to uncommitted sexual relationships (i.e., individual differences in women's sociosexual orientation); women who are more open to uncommitted sexual relationships might show stronger positive effects of conception probability on masculinity preferences, as their sexuality is more overt and sexual attitudes and behaviours are more diversified. Consequently, we analysed data from three independent samples (N = 2304, N = 483, and N = 339) to assess whether sociosexual orientation moderates the hypothesised positive effect of conception probability on women's facial masculinity preferences. Analyses showed no evidence that higher conception probability increased preferences for facial masculinity or that sociosexual orientation moderated the effect of conception probability on women's preferences for facial masculinity. While it remains possible that factors other than sociosexual orientation moderate effects of conception probability on masculinity preferences, our null results suggest that the mixed results for the effects of conception probability on facial masculinity preferences in previous studies are unlikely to be a consequence of failing to consider the moderating role of sociosexual orientation.

Associations between sexually submissive and dominant behaviors and sexual function in men and women.

The current study investigated the associations between sexually submissive and dominant behaviors and sexual dysfunction in Finnish men and women. We analyzed three population-based data sets from 2006, 2009, and 2021-2022, including 29,821 participants in total. Participants filled out a questionnaire about their sexually submissive and dominant behaviors, Sexual Distress Scale, Checklist for Early Ejaculation Symptoms and International Index of Erectile Function Questionnaire-5 (men), and Female Sexual Function Index (women). Pearson Correlations showed that for both sexes, sexually submissive (men: r = 0.119, p < 0.001; women: r = 0.175, p < 0.001) and dominant (men: r = 0.150, p < 0.001; women: r = 0.147, p < 0.001) behaviors were both associated with more sexual distress. However, for men, sexually submissive (r = -0.126, p < 0.001) and dominant behaviors (r = -0.156, p < 0.001) were associated with less early ejaculation symptoms. Both sexually submissive (r = 0.040, p = 0.026) and dominant behaviors (r = 0.062, p < 0.001) were also associated with better erectile function while sexually dominant behavior alone was associated with better orgasmic function (r = 0.049, p = 0.007), intercourse satisfaction (r = 0.068, p < 0.001), and overall satisfaction (r = 0.042, p = 0.018). For women, both sexually submissive (r = 0.184, p < 0.001) and dominant behaviors (r = 0.173, p < 0.001) were also associated with better overall female sexual function. One possible explanation is that these individuals have a clear idea of what they prefer sexually facilitating arousal. Particularly, sexually submissive behavior may reduce high-level self-awareness and, in this way, contribute to reduced performance anxiety. However, non-normative interests seem to simultaneously result in increased sexual distress probably due to the absence of self-acceptance. Further research about the causal mechanisms between non-normative sexual interest and sexual function is needed.

Premature ejaculation among Chinese urban men: prevalence and correlates.

Background: Premature ejaculation (PE) is a common male sexual dysfunction worldwide. It leads to substantial distress in men and their partners, constitutes a serious threat to the quality and stability of romantic relationships, and results in a decreased quality of life in a large part of the population. Aim: We investigated the prevalence of PE and correlated factors in an urban sample of Chinese men. Methods: In total, 1976 Chinese men aged 18 to 50 years responded to an online questionnaire regarding background information, present and previous sexual experience, frequency of different types of sex, as well as erectile and ejaculatory function. Outcomes: Participants' age, assigned sex at birth, sexual identity, relationship status, present and previous sexual experience, frequency of sexual activities, International Index of Erectile Function-5, and Checklist for Early Ejaculation Symptoms were used in the analyses. Results: Forty-four (2.3%) participants had scores that were indicative or strongly indicative of PE, which was highly correlated with erectile problems. Men with more sexual experience (ie, more sexual partners and longer duration of being sexually active) had fewer ejaculatory problems. More frequent masturbation was associated with ejaculatory problems when controlling for age and education. More frequent partnered sex (ie, penile-vaginal sex) was associated with fewer ejaculatory problems. Ejaculation latency times for different types of sexual activities were positively correlated. Clinical Translation: The results indicated that ejaculatory problems have complex relationships with sexual experience that clinicians should be aware of. Strengths and Limitations: This study was the first to investigate PE with the Checklist for Early Ejaculation Symptoms as the measurement tool and the associations between PE and sexual experience, frequency of sexual activities, and sexual function in a large Chinese sample. However, self-reported ejaculation latency times may suffer from problems with validity. Conclusion: Men's sexual experience (ie, more sexual partners and longer duration of being sexually active) has an effect on their sexual function, which in turn affects their sexual activity.

Effects of Ginger on Disgust, Sexual Arousal, and Sexual Engagement: A Placebo-Controlled Experiment.

Sexual problems are common complaints across countries and cultures, and behavioral immune system theory suggests disgust plays an essential role in sexual functioning. The current study investigated 1) if disgust induced by sexual body fluids would reduce sexual arousal, reduce the likelihood of sexual engagement, and enhance disgust toward subsequent erotic stimuli, and 2) if the administration of ginger would affect these reactions. We administered either ginger or placebo pills to a sample of 247 participants (Mage = 21.59, SD = 2.52; 122 women) and asked them to complete either behavioral approach tasks with sexual body fluids or with neutral fluids. Next, participants viewed and responded to questions concerning erotic stimuli (nude and seminude pictures of opposite-sex models). As expected, the sexual body fluids tasks induced disgust. The elevated disgust induced by sexual body fluids tasks resulted in lower sexual arousal in women, whereas ginger consumption counteracted this inhibiting effect of disgust on sexual arousal. Disgust elicited by sexual body fluids also increased disgust toward the subsequent erotic stimuli. Ginger increased sexual arousal toward the erotic stimuli in both men and women who had completed the neutral fluids tasks. Findings provide further evidence of the role of disgust in sexual problems, and, importantly, that ginger may improve the sexual function of individuals via its sexual arousal-enhancing effect.

Does Sexual Desire Fluctuate More Among Women than Men?

There is a lay assumption that women's sexual desire varies substantially over time, whereas men's is stable. This assumption is mirrored in prominent theories of desire, which posit that women are more variable than men in the extent to which they desire sex, and that women's sexual desire is more contextually sensitive than men's. We tested this assumption across three longitudinal studies. Study 1 assessed desire at 3 time points spanning 13 years (Nobservations = 5562), and Studies 2 and 3 (Nobservations = 11,282) assessed desire moment-to-moment over 7 days. When desire was measured over years, women were more variable in their sexual desire than men (Study 1). However, we found a different pattern of results when desire was measured over the short term. In Studies 2 and 3, we found no significant differences in women's and men's desire variability. The extent to which desire varied as a function of affective states (e.g., happiness) and relationship-oriented states (e.g., partner closeness) was similar for women and men, with some exceptions; women's desire was more negatively associated with tiredness and anger in Study 2. These data qualify existing assumptions about sex differences in sexual desire variability.

Causal Influences of Same-Sex Attraction on Psychological Distress and Risky Sexual Behaviors: Evidence for Bidirectional Effects.

Although health disparities among same-sex attracted compared to heterosexual individuals are typically explained by minority stress, there is limited evidence for a causal effect. This study investigated whether same-sex attraction was causally associated with psychological distress and risky sexual behavior using sociosexual behavior as a proxy. The sample comprised monozygotic and dizygotic twins and their non-twin siblings (n = 2036, 3780 and 2356, respectively) genotyped and assessed for same-sex attraction, psychological distress (anxiety and depressive symptoms), and risky sexual behavior. Causal influences were investigated with same-sex attraction as the predictor and psychological distress and risky sexual behavior as the outcomes in two separate Mendelian Randomization-Direction of Causation (MRDoC) models using OpenMx in R. The MRDoC model improves on the Mendelian Randomization and Direction of Causation twin models by allowing analyses of variables with similar genetic architectures, incorporating polygenic scores as instrumental variables and specifying pleiotropy and residual covariance. There were significant causal influences flowing from same-sex attraction to psychological distress and risky sexual behavior (standardized coefficients = 0.13 and 0.16; 95% CIs 0.03-0.23 and 0.08-0.25, respectively). Further analyses also demonstrated causal influences flowing from psychological distress and risky sexual behavior toward same-sex attraction. Causal influences from same-sex attraction to psychological distress and risky sexual behavior may reflect minority stress, which reinforces ongoing measures to minimize social disparities. Causal influences flowing in the opposite direction may reflect rejection sensitivity, stigma-inducing outcomes of risky sexual behavior, and recall bias; however, further research is required to specifically investigate these processes.

Bidirectional Causal Associations Between Same-Sex Attraction and Psychological Distress: Testing Moderation and Mediation Effects.

Only one study has examined bidirectional causality between sexual minority status (having same-sex attraction) and psychological distress. We combined twin and genomic data from 8700 to 9700 participants in the UK Twins Early Development Study cohort at ≈21 years to replicate and extend these bidirectional causal effects using separate unidirectional Mendelian Randomization-Direction of Causation models. We further modified these models to separately investigate sex differences, moderation by childhood factors (retrospectively-assessed early-life adversity and prospectively-assessed childhood gender nonconformity), and mediation by victimization. All analyses were carried out in OpenMx in R. Same-sex attraction causally influenced psychological distress with significant reverse causation (beta = 0.19 and 0.17; 95% CIs = 0.09, 0.29 and 0.08, 0.25 respectively) and no significant sex differences. The same-sex attraction → psychological distress causal path was partly mediated by victimization (12.5%) while the reverse causal path was attenuated by higher childhood gender nonconformity (moderation coefficient = -0.09, 95% CI: -0.13, -0.04).

The Prevalence of BDSM in Finland and the Association between BDSM Interest and Personality Traits.

According to previous research, interest in BDSM (Bondage-Discipline, Dominance-Submission and Sadomasochism) activities is high in several European countries and various BDSM practices are not uncommon. There is a limited amount of research on the personalities of BDSM practitioners, but in previous research practitioners have been found to have better overall well-being and to be more educated than the general population. The current study explored the prevalence of BDSM interest and practice in a Finnish sample (n = 8,137, age range 18-60, M = 30.14, SD = 8.08) and investigated the association between BDSM interest and personality measured with the six-factor personality measure HEXACO. A total of 38% of the sample was interested in BDSM sex and non-heterosexual individuals displayed almost twice as much interest and at most 83% more participation in BDSM than heterosexual individuals. Younger participants (18-28 years old) displayed almost three times as much interest than older participants. There were some associations between BDSM interest and personality factors, but the effect sizes of these associations were modest. The study shows that BDSM interest is quite common among the Finnish population.

Mental health among sexual and gender minorities: A Finnish population-based study of anxiety and depression discrepancies between individuals of diverse sexual orientations and gender minorities and the majority population.

Substantial empirical evidence suggests that individuals who belong to sexual and gender minorities experience more anxiety and depression than heterosexual and cisgender people. Many previous studies have not, however, used population-based samples. There is also a shortage of evidence about certain sexual and gender minorities (e.g., nonbinary individuals). We examined differences in levels of anxiety and depression within sexual and gender minorities, as well as compared to the heterosexual and cisgender majority in a population-based Finnish sample (N = 8,589). We also explored if individuals who belong to both a gender and a sexual minority (double minority) reported higher rates of anxiety and depression than individuals who hold either a gender or a sexual minority status (single minority). Individuals who belonged to either a sexual or a gender minority overall experienced significantly higher rates of anxiety and depression than cisgender and heterosexual individuals. Among the different sexual and gender minorities, bisexual, emerging identity, and nonbinary individuals reported the highest rates of anxiety and depression. We found no differences in anxiety and depression between single minority and double minority individuals. Our results suggest that even though Finland is a country with an inclusive social climate, sexual and gender minorities are, nevertheless, disproportionately affected by mental health issues. The present study gives further support to the claim that individuals holding a sexual or gender minority status experience higher levels of depression and anxiety compared to cisgender and heterosexual individuals and pinpoints the need to acknowledge these issues both in the context of health care and in the society at large.

An Exploratory Network Analysis of Sexual and Relationship Satisfaction Comparing Partnered Cisgendered Men and Women.

BACKGROUND: Sexual and relationship satisfaction are intimately connected and share many predictors. AIM: The aim of the present study is to disentangle the relationship between sexual and relationship satisfaction, by exploring the connections to other relevant correlates. METHODS: Regularized mixed graphical model networks were estimated separately for men and women, which were compared using the network comparison test. In addition, strength centrality and community structure were explored. OUTCOME: The partial correlation structure between sexual satisfaction, relationship satisfaction and their correlates. RESULTS: The associations between variables measuring sexual and relationship satisfaction and related constructs did not differ significantly between partnered, cisgendered men and women. Sexual and relationship satisfaction were associated with sexual pleasure, sexual distress, and sexual communication for both men and women. Sexual satisfaction was the most central variable in the network for men (strength = 1.1), while sexual desire was the most central variable for women (strength = 1.1). Frequency of sexual activity was a central variable for both men and women (strength men = 1.0, strength women = 1.1). The community analysis showed similar communities of variables for men and women, except that frequency of sexual activity consistently belonged to the same community as sexual and relationship satisfaction for men, but not as consistently for women. CLINICAL TRANSLATION: The results have clinical implication in sex and couples therapy, as they increase the knowledge on sexual and relationship satisfaction. STRENGTHS & LIMITATIONS: A strength of the study is the population-based dataset, and a limitation is that inferences of causality cannot be made due to the cross-sectional study design. CONCLUSION: The present study suggests that men and women are largely similar when comparing constructs related to sexual and relationship satisfaction. Nickull S, Källström M, Jern P. An Exploratory Network Analysis of Sexual and Relationship Satisfaction Comparing Partnered Cisgendered Men and Women. J Sex Med 2022;19:711-718.

Increased depressive and anxiety symptoms in non-heterosexual individuals: Moderation by childhood factors using a twin design.

BACKGROUND: Evidence indicates that minority stress does not sufficiently explain mental health disparities in non-heterosexual compared to heterosexual individuals. We investigated alternative mechanisms whereby childhood factors (childhood gender nonconformity, early-life adversities and parent-child interactions) moderate the relationships between sexual orientation and depressive and anxiety symptoms. METHODS: The sample comprised twin pairs from the Finnish Genetics of Sexuality and Aggression cohort (n = 3166 individuals, mean age = 37.5 ± 2.93 years). Twin analyses using structural equation modelling was performed in OpenMx. Specifically, we tested whether childhood factors differentially moderated the underlying genetic and environmental influences on the relationships between sexual orientation, and depressive and anxiety symptoms. RESULTS: The associations between non-heterosexuality, and depressive and anxiety symptoms (r = 0.09, 0.10 respectively) were significantly influenced by both genetic and environmental factors. The genetic influences explaining the relationships of sexual orientation with depressive and anxiety symptoms were maximal at high levels of childhood gender nonconformity (ßA = 0.09 and 0.11 respectively) whereas the individual-specific environmental influences on these relationships were maximal at lower levels of childhood gender nonconformity (ßE = -0.10). LIMITATIONS: Childhood factors were assessed retrospectively in a cross-sectional design. CONCLUSIONS: Childhood gender nonconformity is associated with increased genetic and decreased individual-specific environmental influences on mental health among non-heterosexual individuals. Childhood gender nonconformity may, thus, enhance genetic risk and non-genetic protective processes for depressive and anxiety symptoms among non-heterosexual individuals.

Do psychosocial factors mediate sexual minorities' risky sexual behaviour? A twin study.

OBJECTIVES: Risky sexual behavior among sexual minorities (lesbian, gay, and bisexual individuals) are partly attributed to mental health and other social disparities; but this may be confounded by correlated genetic and environmental influences. As preregistered, the present study investigated indirect associations between sexual minority status and increased lifetime sexual partners through increased psychosocial adversity (depressive and anxiety symptoms, intimate partner violence, and early life adversities) and substance use (alcohol, cannabis, and other illicit drugs), confounding by correlated genetic and environmental influences, and sex differences in these relationships. METHOD: The sample comprised sexual minority and heterosexual twins who participated in the first and second phases of the latest wave of data collection in the U.K. population-based Twins Early Development study cohort (June 2017 through February 2019; n = 9,697 and 8,718, respectively, Mage = 22.3 ± .92 years). Structural equation modeling was used to specify psychosocial adversity and substance use as mediators while genetic and environmental confounding was further determined by biometrical genetic analyses in which similarities in identical and nonidentical twins were compared. RESULTS: Increased psychosocial adversity and substance use fully mediated increased lifetime sexual partners in sexual minority women while this effect was partial (31.1%) in men. The best-fitting genetic models indicated that these relationships were not confounded by correlated genetic and environmental influences. CONCLUSIONS: The relationships between sexual minority status, psychosocial adversity, substance use, and sexual health disparities appeared independent of genetic and environmental influences. Individual and systemic interventions to reduce psychosocial disadvantage and substance use can also decrease sexual health disparities among sexual minorities. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

µ-opioid receptor availability is associated with sex drive in human males.

The endogenous mu-opioid receptor (MOR) system modulates a multitude of social and reward-related functions, and exogenous opiates also influence sex drive in humans and animals. Sex drive shows substantial variation across humans, and it is possible that individual differences in MOR availability underlie interindividual of variation in human sex drive. We measured healthy male subjects' (n = 52) brain's MOR availability with positron emission tomography (PET) using an agonist radioligand, [11C]carfentanil, that has high affinity for MORs. Sex drive was measured using self-reports of engaging in sexual behaviour (sex with partner and masturbating). Bayesian hierarchical regression analysis revealed that sex drive was positively associated with MOR availability in cortical and subcortical areas, notably in caudate nucleus, hippocampus, and cingulate cortices. These results were replicated in full-volume GLM analysis. These widespread effects are in line with high spatial autocorrelation in MOR expression in human brain. Complementary voxel-based morphometry analysis (n = 108) of anatomical MR images provided limited evidence for positive association between sex drive and cortical density in the midcingulate cortex. We conclude that endogenous MOR tone is associated with individual differences in sex drive in human males.