Sexual differentiation of human behavior: effects of prenatal and pubertal organizational hormones

Under the influence: exogenous testosterone influences men's cross-sex perceptions of sexual interest

The sexual misperception bias is a cognitive bias in which men tend to overestimate sexual interest from women, potentially shaped by evolutionary mating strategies. Testosterone, often linked to mating behaviors, might play a role in sustaining sexual overperceptions. To explore this possibility, we conducted a placebo-controlled study with 190 heterosexual men, administering either 11 mg of testosterone or a placebo. Participants interacted with an attractive female confederate, while naïve raters assessed the confederate's affiliative behaviors. Our findings suggest that exogenous testosterone did not broadly impact sexual overperception. However, we found that affiliative behavior from the confederate was positively correlated with perceived sexual interest among testosterone-treated, but not placebo-treated men. In addition, we found that this effect among testosterone-treated men was contingent on their self-perceived attractiveness. Specifically, the confederate's affiliative behaviors were positively correlated with perceived sexual interest, but only for testosterone-treated men with average or above average self-perceived attractiveness. Furthermore, our data revealed that men's tendency to project their own short-term and long-term mating interests increases as a function of self-perceived attractiveness, and this coupling is enhanced by testosterone for long-term interest. Taken together, these results suggest that testosterone may potentiate existing biases, particularly when sexual motivation is high, and bias perceptions of friendly behavior when engaging in cross-sex mindreading. This study adds to the understanding of the neuroendocrine bases of social cognition, suggesting that testosterone can affect men's perceptions of potential mates.

Starting the pill during adolescence: Age of onset and duration of use influence morphology of the hippocampus and ventromedial prefrontal cortex

From adolescence, women become more likely to experience fear dysregulation. Oral contraceptives (OCs) can modulate the brain regions involved in fear processes. OCs are generally used for years and often initiated during adolescence, a sensitive period where certain brain regions involved in the fear circuitry are still undergoing important reorganization. It remains unknown whether OC use during adolescence may induce long-lasting changes in the fear circuitry. This study aimed to examine whether age of onset moderated the relationship between duration of use and fear-related brain structures. We collected structural MRI data in 98 healthy adult women (61 current users, 37 past users) and extracted grey matter volumes (GMV) and cortical thickness (CT) of key regions of the fear circuitry. Non-linear multiple regressions revealed interaction effects between age of onset and quadratic duration of use on GMV of the right hippocampus and right ventromedial prefrontal cortex (vmPFC). Among women who initiated OCs earlier in adolescence, a short duration of use was associated with smaller hippocampal GMV and thicker vmPFC compared to a longer duration of use. For both GMV and CT of the right vmPFC, women with an early OC onset had more grey matter at a short duration of use than those with a later onset. Our results suggest that OC use earlier in adolescence may induce lasting effects on structural correlates of fear learning and its regulation. These findings support further investigation into the timing of OC use to better comprehend how OCs could disrupt normal brain development processes.

Sex-specific associations of a ferroalloy metal mixture with motor function in Italian adolescents

Background

Motor function is critical for children's health, yet remains an understudied neurodevelopmental domain. Exposure to metals has been linked with motor function, but no study has examined the joint effects of metal mixtures.

Methods

We evaluated cross-sectional associations between a metal mixture and motor function among 569 adolescents (10-14 years old) living near the ferroalloy industry. Concentrations of blood lead, hair manganese, hair copper, and hair chromium were quantified using inductively coupled plasma mass spectrometry. Neuropsychologists administered multiple fine motor function assessments: pursuit aiming, finger tapping, visual reaction time (VRT), and subtests from the Luria Nebraska battery. We estimated associations between motor function and the metal mixture using quantile-based g-computation and multivariable linear regression, adjusting for child age, sex, and socioeconomic status. We explored sex-specific associations in stratified models.

Results

Associations between the metal mixture and motor function were mostly null but were modified by sex. We observed a beneficial association among females: a quartile increase in all metals in the mixture was associated with a 2.6% faster average response time on the VRT (95% confidence interval [CI] = -4.7%, -0.5%), driven by Cu and Cr. In contrast, this association was adverse among males (ß = 1.5% slower response time [95% CI = -0.7%, 3.9%]), driven by Cu and Mn.

Conclusions

Results suggest that males may be more susceptible to the adverse effects of metal exposure on motor function during adolescence than females. Future studies, particularly prospective study designs, are warranted to further understand the associations of metal mixtures with motor function.

Hormonal contraceptives and behavior: Updating the potent state of the nascent science

Hundreds of millions of people worldwide use hormonal contraceptives (HCs), which have been an essential part of women's reproductive health care for decades. Throughout that time, however, research on the neural and behavioral consequences of HCs was minimal and plagued by poor methodology. HC effects - and users - were assumed to be homogenous. Fortunately, there has been a recent upswell in the number and quality of investigations, affording tentative conclusions about the roles of HCs in spatial cognition and mental health, particularly depression. Thus, this paper leverages findings from the past few years to highlight the heterogeneous aspects of use that seem to matter for behavior - ranging from variation in hormonal contraceptive formulations and routes of administration to individual differences among users linked to age and reproductive health history. This paper closes with five tips for future research that will help capture and clarify heterogeneity in potential relations between HCs and behavior, namely data collection, regional access, lifespan factors, gender, and collaboration. HCs are sociopolitically provocative and research on their potential behavioral neuroendocrine impacts is becoming increasingly popular. It is, therefore, imperative for scientists to conduct replicable and robust empirical investigations, and to communicate findings with the nuance that the heterogeneity among users and effects requires.

Sex and Sexual Orientation Differences in Dark Triad Traits, Sexual Excitation/Inhibition, and Sociosexuality

The present study sought to investigate sex and sexual orientation differences in several traits related to sexuality and sexual behavior. Examining sexual orientation differences alongside basic sex differences to help identify correlates of sexual orientation diversity, and whether individuals with varying degrees of same-sex attraction show concurrent sex-atypical shifts in other domains. Males tend to score higher than females in the Dark Triad (DT) traits of sub-clinical narcissism, psychopathy, and Machiavellianism. Similarly, females tend to be more cautious than males in their attitudes and desires toward casual sex activity (i.e., sociosexuality). These sex differences may be related to the propensity for individuals to become easily sexually excited, which is higher in males, or to instead inhibit sexual arousal, which is higher in females. In a large undergraduate sample (N = 2047), we replicated expected sex differences in DT traits, sociosexuality, and sexual excitation/inhibition. We found that non-heterosexual females were "male-shifted" in some of these traits, but these shifts tended to be strongest among mostly heterosexual and bisexual individuals. Furthermore, we found that within-sex variation in sociosexuality, sexual excitation, and sexual inhibition was not related to sexual orientation in a linear fashion. Instead, sociosexuality and sexual excitation were related to sexual orientation in a curvilinear (inverted-U) fashion, especially among females. The fact that traits correlated with bisexuality and homosexuality were somewhat distinct is consistent with the idea that different developmental pathways may lead to these discrete sexual attraction patterns.

Explaining work addiction through perceived behaviors of significant others in a family and organization: Gender differences

The objective of the study was to investigate the association between employees' work addiction and perceived work addiction of their immediate managers and parents, separate in samples of men and women. A total of 964 Lithuanian employees took part in the study. The levels of work addiction were assessed using the Bergen Work Addiction Scale (Andreassen, Griffiths, Hetland & Pallesen, 2012). We used the same scale to measure work addiction of the employees and perceived work addiction of their parents and immediate managers. The results showed that perceived work addiction of both parents and managers was related to higher levels of work addiction in women. We further found that the positive relationship between perceived work addiction of mothers and men's work addiction was as strong as the association between perceived work addiction of managers and men's work addiction. The positive relationship between perceived work addiction of fathers and men's work addiction was weaker as compared to that between perceived work addiction of managers and men's work addiction. All independent variables accounted for a greater part of the variance in work addiction of men than that of women.

Testosterone, gender identity and gender-stereotyped personality attributes

Sex/gender differences in personality associated with gender stereotyped behavior are widely studied in psychology yet remain a subject of ongoing debate. Exposure to testosterone during developmental periods is considered to be a primary mediator of many sex/gender differences in behavior. Extensions of this research has led to both lay beliefs and initial research about individual differences in basal testosterone in adulthood relating to "masculine" personality. In this study, we explored the relationships between testosterone, gender identity, and gender stereotyped personality attributes in a sample of over 400 university students (65 % female assigned at birth). Participants provided ratings of their self-perceived masculinity and femininity, resulting in a continuous measure of gender identity, and a set of agentic and communal personality attributes. A saliva sample was also provided for assay of basal testosterone. Results showed no compelling evidence that basal testosterone correlates with gender-stereotyped personality attributes or explains the relationship between sex/gender identity and these attributes, across, within, or covarying out sex assigned at birth. Contributing to a more gender diverse approach to assessing sex/gender relationships with personality and testosterone, our continuous measure of self-perceived masculinity and femininity predicted additional variance in personality beyond binary sex and showed some preliminary but weak relationships with testosterone. Results from this study cast doubt on the activational testosterone-masculinity hypothesis for explaining sex differences in gender stereotyped traits and within-sex/gender variation in attributes associated with agency and communality.

Recommendations for 46,XX Congenital Adrenal Hyperplasia Across Two Decades: Insights from the North American Differences of Sex Development Clinician Survey

Several aspects of clinical management of 46,XX congenital adrenal hyperplasia (CAH) remain unsettled and controversial. The North American Disorders/Differences of Sex Development (DSD) Clinician Survey investigated changes, over the last two decades, in clinical recommendations by specialists involved in the management of newborns with DSD. Members of the (Lawson Wilkins) Pediatric Endocrine Society and the Societies for Pediatric Urology participated in a web-based survey at three timepoints: 2003-2004 (T1, n = 432), 2010-2011 (T2, n = 441), and 2020 (T3, n = 272). Participants were presented with two clinical case scenarios-newborns with 46,XX CAH and either mild-to-moderate or severe genital masculinization-and asked for clinical recommendations. Across timepoints, most participants recommended rearing the newborn as a girl, that parents (in consultation with physicians) should make surgical decisions, performing early genitoplasty, and disclosing surgical history at younger ages. Several trends were identified: a small, but significant shift toward recommending a gender other than girl; recommending that adolescent patients serve as the genital surgery decision maker; performing genital surgery at later ages; and disclosing surgical details at younger ages. This is the first study assessing physician recommendations across two decades. Despite variability in the recommendations, most experts followed CAH clinical practice guidelines. The observation that some of the emerging trends do not align with expert opinion or empirical evidence should serve as both a cautionary note and a call for prospective studies examining patient outcomes associated with these changes.

Do Hormone Levels Influence Bullying during Childhood and Adolescence? A Systematic Review of the Literature

(1) Background: Bullying is one of the most common forms of aggressive behavior during childhood and adolescence. Some decades ago, researchers began exploring the basis of peer victimization from a biological perspective. Specifically, the Hypothalamic-Pituitary-Adrenal (HPA) and Hypothalamic-Pituitary-Gonadal (HPG) axes have been studied in relation to status-relevant behaviors, such as bullying. (2) Methods: We conducted a systematic review following the PRISMA guide and registered the review protocol at PROSPERO (CRD42023494738). We searched for relevant studies in PubMed, Psycinfo, Scopus, and Web of Science, and assessed them using the Robins E-tool. (3) Results: Our search yielded 152 studies, of which 33 were included in the review. These studies explored the association between testosterone and cortisol levels with bullying behavior, finding diverse results. Most of the studies were rated as having a low risk of bias. (4) Conclusions: This study not only enhances our understanding of bullying, but also provides guidance for the development of prevention and management programs for it. In the future, researchers should continue exploring the joint effects of different hormones on the HPA and HPG axis, using a broader set of biomarkers.

Sex steroids and the female brain across the lifespan: insights into risk of depression and Alzheimer's disease

Despite widespread sex differences in prevalence and presentation of numerous illnesses affecting the human brain, there has been little focus on the effect of endocrine ageing. Most preclinical studies have focused on males only, and clinical studies often analyse data by covarying for sex, ignoring relevant differences between the sexes. This sex- (and gender)-neutral approach is biased and contributes to the absence of targeted treatments and services for all sexes (and genders). Female health has been historically understudied, with grave consequences for their wellbeing and health equity. In this Review, we spotlight female brain health across the lifespan by informing on the role of sex steroids, particularly oestradiol, on the female brain and on risk for diseases more prevalent in females, such as depression and Alzheimer's disease.

Developmental changes in endogenous testosterone have sexually-dimorphic effects on spontaneous cortical dynamics

The transition from childhood to adolescence is associated with an influx of sex hormones, which not only facilitates physical and behavioral changes, but also dramatic changes in neural circuitry. While previous work has shown that pubertal hormones modulate structural and functional brain development, few of these studies have focused on the impact that such hormones have on spontaneous cortical activity, and whether these effects are modulated by sex during this critical developmental window. Herein, we examined the effect of endogenous testosterone on spontaneous cortical activity in 71 typically-developing youth (ages 10-17 years; 32 male). Participants completed a resting-state magnetoencephalographic (MEG) recording, structural MRI, and provided a saliva sample for hormone analysis. MEG data were source-reconstructed and the power within five canonical frequency bands (delta, theta, alpha, beta, and gamma) was computed. The resulting power spectral density maps were analyzed via vertex-wise ANCOVAs to identify spatially specific effects of testosterone and sex by testosterone interactions, while covarying out age. We found robust sex differences in the modulatory effects of testosterone on spontaneous delta, beta, and gamma activity. These interactions were largely confined to frontal cortices and exhibited a stark switch in the directionality of the correlation from the low (delta) to high frequencies (beta/gamma). For example, in the delta band, greater testosterone related to lower relative power in prefrontal cortices in boys, while the reverse pattern was found for girls. These data suggest testosterone levels are uniquely related to the development of spontaneous cortical dynamics during adolescence, and such levels are associated with different developmental patterns in males and females within regions implicated in executive functioning.

Cognitive development from infancy to young adulthood in common marmosets (Callithrix jacchus): Effect of age, sex, and hormones on learning and affective state

Studies looking at individual variability in cognition have increased in recent years. We followed 43 marmosets (21 males, 22 females) from infancy to young adulthood. At 3-months old, marmosets were trained to touch a rewarded stimulus. At 9-, 15-, and 21-months old, they were given visual discrimination and cognitive bias tests, and urine samples were collected to examine hormone levels. Marmosets were significantly more successful learners at 15 months than 9 months. Individuals who were more successful learners at 9 months were also more successful at 15 months, with more male learners than expected at 15 months. At 9 months, learning success was associated with higher cortisol levels. At 15 months, males with higher estradiol levels were more successful learners, whereas at 21 months, females with higher estradiol and cortisol levels tended to be less successful learners and more pessimistic. Nine months, therefore, appears to be an important developmental timepoint for acquiring cognitive control, which has developed by 15 months. Steroids may have differential effects on each sex, with complex interactions between gonadal and adrenal hormones having an influence on cognitive function over the lifespan. This longitudinal study offers new insight into cognition, including its development and biological underpinnings.

Early prenatal sex steroids and sex-typed play behavior at 4 years of age

During pregnancy, estrogens and testosterone influence brain development, resulting in sex-typical behavioral phenotypes. Prenatal testosterone exposure is associated with more male-typical behaviors in rodents, monkeys, and humans; however, few studies have examined the relationship between maternal sex hormones within the normal range and sex-dimorphic behaviors. In this study, we examined associations between prenatal estrogens and testosterone and sex-typical play in The Infant Development and the Environment Study (TIDES), a multicenter pregnancy cohort. We collected prenatal serum during the first trimester (mean=11.1 ± 2.6 weeks) and assessed child play behavior using the maternally completed Pre-School Activities Inventory (PSAI) at a mean age of 4.5 ± 0.3 years. This analysis includes mother-child pairs with complete data on hormones, play behavior, and covariates (n = 192 boys and 207 girls). No associations were seen between testosterone and PSAI scores in boys or girls or between estrogens and PSAI scores in boys. In girls, we observed an inverse relationship between feminine PSAI scores and both estradiol (E2) and estriol (E3) in multivariable linear regression analyses (E2: -0.11 [95% CI -0.20, -0.02]; E3: -0.44 [95% CI -0.83,-0.04]). Because the relationship between sex hormones and PSAI scores appeared nonlinear, we fit piecewise regression models to better fit the data and identify inflection points (point at which there is a significant change in slope). Piecewise regression analyses yielded inverse associations between masculine PSAI scores and estrone (E1) at values of E1 > 1340 pg/mL and E2 at values of E2 > 2870 pg/mL in girls. Further studies are needed to better understand the role of prenatal sex steroids on sexually dimorphic behavior.

Sex/gender differences in cognitive abilities

Sex/gender differences in cognitive sciences are riddled by conflicting perspectives. At the center of debates are clinical, social, and political perspectives. Front and center, evolutionary and biological perspectives have often focused on 'nature' arguments, while feminist and constructivist views have often focused on 'nurture arguments regarding cognitive sex differences. In the current narrative review, we provide a comprehensive overview regarding the origins and historical advancement of these debates while providing a summary of the results in the field of sexually polymorphic cognition. In so doing, we attempt to highlight the importance of using transdisciplinary perspectives which help bridge disciplines together to provide a refined understanding the specific factors that drive sex differences a gender diversity in cognitive abilities. To summarize, biological sex (e.g., birth-assigned sex, sex hormones), socio-cultural gender (gender identity, gender roles), and sexual orientation each uniquely shape the cognitive abilities reviewed. To date, however, few studies integrate these sex and gender factors together to better understand individual differences in cognitive functioning. This has potential benefits if a broader understanding of sex and gender factors are systematically measured when researching and treating numerous conditions where cognition is altered.

In support of 2D:4D: More data exploring its conflicting results on handedness, sexual orientation and sex differences

In the last few years, several studies have questioned the value of the second-to-fourth digit ratio (2D:4D) as a measure of exposure to sex hormones before birth. Controversy has also extended to the 2D:4D association with individual features previously related to this exposure such as handedness and sexual orientation. Given that it has been argued that sex differences in 2D:4D could be a consequence of body-size differences, we have tested in a large sample the allometric relationship between finger lengths and body size. Our results show that the association is either allometric or isometric, depending on the analyses performed. In any case, the deviation from isometry is not large enough to explain the typically observed sex difference in this trait. We have also tested the association between sexual orientation and 2D:4D, finding a relationship between 2D:4D and sexual orientation in men but not in women. We attribute this discordance with previously published meta-analysis to differences in genetic background, a variable that has gained relevance in recent years in studies involving 2D:4D. Finally, we did not find any relationship between 2D:4D and handedness, evaluated through self-reported preference and hand performance. Our main conclusion is that 2D:4D shows differences between sexes beyond their disparity in body size. In our opinion, 2D:4D can be used cautiously as an indicator of intrauterine exposure to sex hormones taking into account some considerations, such as analysing a very large sample and taking careful measurements of the ethnicity of the sample.

Does the primate face cue personality?

When looking at others, primates primarily focus on the face - detecting the face first and looking at it longer than other parts of the body. This is because primate faces, even without expression, convey trait information crucial for navigating social relationships. Recent studies on primates, including humans, have linked facial features, specifically facial width-to-height ratio (fWHR), to rank and Dominance-related personality traits, suggesting these links' potential role in social decisions. However, studies on the association between dominance and fWHR report contradictory results in humans and variable patterns in nonhuman primates. It is also not clear whether and how nonhuman primates perceive different facial cues to personality traits and whether these may have evolved as social signals. This review summarises the variable facial-personality links, their underlying proximate and evolutionary mechanisms and their perception across primates. We emphasise the importance of employing comparative research, including various primate species and human populations, to disentangle phylogeny from socio-ecological drivers and to understand the selection pressures driving the facial-personality links in humans. Finally, we encourage researchers to move away from single facial measures and towards holistic measures and to complement perception studies using neuroscientific methods.

Prenatal androgen influences on the brain: A review, critique, and illustration of research on congenital adrenal hyperplasia

Sex hormones, especially androgens, contribute to sex and gender differences in the brain and behavior. Organizational effects are particularly important because they are thought to be permanent, reflecting hormone exposure during sensitive periods of development. In human beings, they are often studied with natural experiments in which sex hormones are dissociated from other biopsychosocial aspects of development, such as genes and experiences. Indeed, the greatest evidence for organizational effects on sex differences in human behavior comes from studies of females with congenital adrenal hyperplasia (CAH), who have heightened prenatal androgen exposure, female-typical rearing, and masculinized toy play, activity and career interests, spatial skills, and some personal characteristics. Interestingly, however, neuroimaging studies of females with CAH have revealed few neural mechanisms underlying these hormone-behavior links, with the exception of emotion processing; studies have instead shown reduced gray matter volumes and reduced white matter integrity most consistent with other disease-related processes. The goals of this narrative review are to: (a) describe methods for studying prenatal androgen influences, while offering a brief overview of behavioral outcomes; (b) provide a critical methodological review of neuroimaging research on females with CAH; (c) present an illustrative analysis that overcomes methodological limitations of previous work, focusing on person-specific neural reward networks (and their associations with sensation seeking) in women with CAH and their unaffected sisters in order to inform future research questions and approaches that are most likely to reveal organizational hormone effects on brain structure and function.

Chromosomal and gonadal factors regulate microglial sex effects in the aging brain

Biological sex contributes to phenotypic sex effects through genetic (sex chromosomal) and hormonal (gonadal) mechanisms. There are profound sex differences in the prevalence and progression of age-related brain diseases, including neurodegenerative diseases. Inflammation of neural tissue is one of the most consistent age-related phenotypes seen with healthy aging and disease. The pro-inflammatory environment of the aging brain has primarily been attributed to microglial reactivity and adoption of heterogeneous reactive states dependent upon intrinsic (i.e., sex) and extrinsic (i.e., age, disease state) factors. Here, we review sex effects in microglia across the lifespan, explore potential genetic and hormonal molecular mechanisms of microglial sex effects, and discuss currently available models and methods to study sex effects in the aging brain. Despite recent attention to this area, significant further research is needed to mechanistically understand the regulation of microglial sex effects across the lifespan, which may open new avenues for sex informed prevention and treatment strategies.

The association of prenatal amniotic sex hormones and digit ratio (2D:4D) in children aged 5 to 70 months: A longitudinal study

The sex difference of the 2D:4D digit ratio (female > male)-a proposed marker for prenatal testosterone exposure-is well established. Studies suggest it already exists in utero and is of moderate effect size in adulthood. However, evidence for the claim that 2D:4D reflects prenatal androgen action is limited, and the sex difference may exhibit lability during childhood. In the present study, 244 mothers were recruited in the course of an amniocentesis examination (performed between gestational weeks 14 and 18). Prenatal testosterone (T) and estradiol (E) levels were determined from amniotic fluid for boys and girls. The majority (97.4%, n = 114) of available female T levels (n = 117) were found below the level of quantification. Therefore, only male amniotic fluid data (n = 117) could be included for the analysis of associations between amniotic sex hormones (T levels and T to E ratio (T/E)) and 2D:4D. The families were then invited to each of the five consecutive follow-ups (ages: 5, 9, 20, 40, and 70 months) where children's 2D:4D was measured for both hands. The alternative marker D[r-l] reflects the directional asymmetry of 2D:4D (right subtracted by left 2D:4D) and was subsequently calculated as an additional measure for prenatal T exposure. No significant correlations between amniotic T or the T/E ratio (measured between week 14 and 18 of gestation) with 2D:4D respectively D[r-l] were observed for any time point. There was a significant sex difference (females > males) and a significant age effect with moderate correlations of 2D:4D between time points. 2D:4D increased between 20 and 40 months and between 40 and 70 months of age. The findings raise questions regarding the applicability of 2D:4D as a marker for prenatal androgen action and are discussed in terms of the reliability of obtained digit ratio data as well as in terms of the developmental timing of amniocentesis.

Sexuality and fertility desire in a large cohort of individuals with 46, XY differences in sex development

OBJECTIVE

To analyze aspects of sexual life and fertility desire among 46, XY DSD people, including those who changed their gender.

METHODS

It is a cross-sectional study including 127 adults (> 16 years of age) with 46, XY DSD (83 females; 44 males) from a Single Brazilian Tertiary-Care Medical Center.

RESULTS

Sexual fantasies and masturbation were more frequent in 46, XY DSD males, whereas orgasm and sexual life satisfaction were similar in both genders. More 46, XY DSD men than women had a long-term romantic relationship. 46, XY DSD women with prenatal androgen exposure reported more fear of being romantically rejected. External genitalia appearance at birth did not impact the sexuality of 46, XY DSD women after surgical genital treatment had been completed. Overall, the sexual life was similar between 46, XY men assigned as males and those who changed to the male gender. Regarding sexual orientation, most self-reported as heterosexual (91% and 92% of women and men, respectively). The desire for fertility had a similar prevalence in both genders, but more women than men considered infertility a barrier to a long-term romantic relationship. Twelve individuals (7 males) had children; 10 out of 12 have adopted children.

CONCLUSION

Fertility desire was shared among 46, XY DSD people, regardless of gender. Prenatal androgen exposure reduced the desire for motherhood in 46, XY women. 46, XY DSD people who changed from female to male gender presented similar sexual parameters as those assigned as males. Among females, virilized genitalia at birth did not affect sexuality once the surgical treatment is completed.

Psychological Femininity and Masculinity and Motivation in Team Sports

It is hypothesized that levels of femininity and masculinity may be relevant to specific types of engagement in action. For this reason, the aim of this study was to search for relationships between psychological dimensions of femininity and masculinity and different forms of motivation, as well as their specific parts, among women and male athletes practicing team sports games. We researched 49 women aged 19 to 32 years representing sports such as football, handball, hockey, volleyball, and basketball and 56 men aged 18 to 31 years practicing football, hockey, volleyball, basketball, and handball. The respondents completed the Inventory to Assess Psychological Gender (IPP) and the Polish adaptation of the Sport Motivation Scale (SMS). It was determined that the psychological dimension of femininity was (in the male group) positively related to the dimension of amotivation, i.e., the lack of perception of a relationship between one's action and the outcome. In turn, the psychological dimension of masculinity was positively related to the motivation to know, motivation to accomplish, and motivation to experience stimulation, as well as the overall level of intrinsic motivation and the overall dimension of extrinsic motivation. Furthermore, the masculinity dimension is, in male athletes, related to the level of the introjection motive, i.e., the process of integrating accepted patterns.

Empathy development from adolescence to adulthood and its consistency across targets

This research was conducted with two main goals-to contribute to knowledge on the development of empathy from early adolescence to adulthood, including its contribution to decoding emotion expression, and to improve the understanding of the nature of empathy by simultaneously assessing empathy toward two different targets-humans and animals. It unfolded into two cross-sectional studies: One (S1) obtaining measures of empathy toward humans and animals as targets across five age groups (from pre-adolescents to adults); and another (S2) where a subset of the adolescents who participated in S1 were assessed in emotion expression decoding and subjective and physiological responses to emotional video clips. The results of S1 showed that empathy toward animals and most dimensions of empathy toward humans increase toward adulthood, with important gender differences in empathy to animals and humans, and empathy levels in girls starting off in the age trajectory at higher levels, A moderate correlation between empathy toward human and toward animal targets was also found. S2 showed that the expression of positive emotion is better recognized than that of negative emotion, surprise, or neutral expression, and that the measure of human-directed empathy predicts successful decoding of negative emotion, whereas skin conductance responses (SCRs) and subjective valence ratings predicted successful identification of positive emotion. Gender differences emerged but not across all age groups nor all subscales. Results yield keys to the developmental "pace" and trajectory of the various dimensions of empathy and to how empathy relates to emotion decoding.

Hormonal contraceptive influences on cognition and psychopathology: Past methods, present inferences, and future directions

In the last decade, there has been a remarkable surge in research on the neural and behavioral correlates of hormonal contraceptive use, particularly oral contraceptive use. Questions have evolved swiftly and notably, with studies no longer revealing if hormonal contraceptives matter for the brain and behavior, but rather how, when, and for whom they matter most. Paralleling this shift, the goal of this review is to move beyond an average synthesis of hormonal contraceptive influences on human cognition and psychopathology (and their neural substrates) in order to consider the nature and specificity of effects. Accompanied by an evaluation of study methods and informed by findings from animal models, this consideration uncovers promising areas of research in the next ten years, including potential activational and organizational effects of hormonal contraceptive use, individual differences in effects that matter for the wellbeing of unique individuals, and correlates of intrauterine device use.

Androgens and male sexual function

Sexual symptoms are the most specific determinants of low testosterone (T) observed during adulthood. In this narrative review, we summarize the most important evidence supporting the positive relationships between endogenous T levels and sexual activity in the adult male, by using preclinical and clinical observations. In addition, we also report an update of our previous meta-analysis evaluating the effects of T treatment (TRT) on sexual functioning in subjects with T deficiency. Available data indicate that TRT of symptomatic hypogonadal men can improve several aspects of sexual life, including erection. However, the effect is rather modest and lower in subjects with associated metabolic conditions. The specific observed effects are similar to those derived from lifestyle intervention. Since TRT might result in body composition improvement, it is reasonable to suppose that an initial treatment with T can improve the willingness of hypogonadal subjects to perform physical exercise and to adhere to a healthier behavior. Similar data were derived from animal models. However, it should be important to recognize that lifestyle modifications should be the first step to promote weigh reduction. TRT can be combined with lifestyle interventions only in symptomatic hypogonadal subjects especially in the presence of comorbid metabolic conditions.

Hormonal contraceptives as disruptors of competitive behavior: Theoretical framing and review

Emerging evidence suggests that hormonal contraceptives (HCs) impact psychological outcomes through alterations in neurophysiology. In this review, we first introduce a theoretical framework for HCs as disruptors of steroid hormone modulation of socially competitive attitudes and behaviors. Then, we comprehensively examine prior research comparing HC users and non-users in outcomes related to competition for reproductive, social, and financial resources. Synthesis of 46 studies (n = 16,290) led to several key conclusions: HC users do not show the same menstrual cycle-related fluctuations in self-perceived attractiveness and some intrasexual competition seen in naturally-cycling women and, further, may show relatively reduced status- or achievement-oriented competitive motivation. However, there a lack of consistent or compelling evidence that HC users and non-users differ in competitive behavior or attitudes for mates or financial resources. These conclusions are tentative given the notable methodological limitations of the studies reviewed. Implications and recommendations for future research are discussed.

Pubertal induction and transition to adult sex hormone replacement in patients with congenital pituitary or gonadal reproductive hormone deficiency: an Endo-ERN clinical practice guideline

An Endo-European Reference Network guideline initiative was launched including 16 clinicians experienced in endocrinology, pediatric and adult and 2 patient representatives. The guideline was endorsed by the European Society for Pediatric Endocrinology, the European Society for Endocrinology and the European Academy of Andrology. The aim was to create practice guidelines for clinical assessment and puberty induction in individuals with congenital pituitary or gonadal hormone deficiency. A systematic literature search was conducted, and the evidence was graded according to the Grading of Recommendations, Assessment, Development and Evaluation system. If the evidence was insufficient or lacking, then the conclusions were based on expert opinion. The guideline includes recommendations for puberty induction with oestrogen or testosterone. Publications on the induction of puberty with follicle-stimulation hormone and human chorionic gonadotrophin in hypogonadotropic hypogonadism are reviewed. Specific issues in individuals with Klinefelter syndrome or androgen insensitivity syndrome are considered. The expert panel recommends that pubertal induction or sex hormone replacement to sustain puberty should be cared for by a multidisciplinary team. Children with a known condition should be followed from the age of 8 years for girls and 9 years for boys. Puberty induction should be individualised but considered at 11 years in girls and 12 years in boys. Psychological aspects of puberty and fertility issues are especially important to address in individuals with sex development disorders or congenital pituitary deficiencies. The transition of these young adults highlights the importance of a multidisciplinary approach, to discuss both medical issues and social and psychological issues that arise in the context of these chronic conditions.

Killing two birds with one stone: Pregnancy is a sensitive window for endocrine effects on both the mother and the fetus

Pregnancy is a complex process requiring tremendous physiological changes in the mother in order to fulfill the needs of the growing fetus, and to give birth, expel the placenta and nurse the newborn. These physiological modifications are accompanied with psychological changes, as well as with variations in habits and behaviors. As a result, this period of life is considered as a sensitive window as impaired functional and physiological changes in the mother can have short- and long-term impacts on her health. In addition, dysregulation of the placenta and of mechanisms governing placentation have been linked to chronic diseases later-on in life for the fetus, in a concept known as the Developmental Origin of Health and Diseases (DOHaD). This concept stipulates that any change in the environment during the pre-conception and perinatal (in utero life and neonatal) period to puberty, can be "imprinted" in the organism, thereby impacting the health and risk of chronic diseases later in life. Pregnancy is a succession of events that is regulated, in large part, by hormones and growth factors. Therefore, small changes in hormonal balance can have important effects on both the mother and the developing fetus. An increasing number of studies demonstrate that exposure to endocrine disrupting compounds (EDCs) affect both the mother and the fetus giving rise to growing concerns surrounding these exposures. This review will give an overview of changes that happen during pregnancy with respect to the mother, the placenta, and the fetus, and of the current literature regarding the effects of EDCs during this specific sensitive window of exposure.

Transgender Youths' Sexual Health and Education: A Qualitative Analysis

STUDY OBJECTIVE

To characterize transgender adolescents' sexual behaviors, identities, and their perceived experiences with sex education.

DESIGN

Semi-structured interviews were conducted and addressed sexual experiences and perceptions of sex education received from family, school educators, and healthcare providers. Interviews were audio recorded, transcribed, and analyzed utilizing NVivo 12 software for thematic analysis.

SETTING

Child and adolescent gender services clinic at a Midwestern university-based medical center in the United States.

PARTICIPANTS

30 transgender adolescents between the ages of 15 to 20.

INTERVENTIONS AND MAIN OUTCOME MEASURES

Themes generated during semi-structured interviews.

RESULTS

Sexual orientations were inclusive of attractions to a spectrum of gender identities. Libido was perceived to be impacted by gender-affirming hormone therapy, which was unanticipated for some adolescents. Family and school-based sex education was perceived to be relevant only for heterosexual and cisgender adolescents. Inclusive education for transgender adolescents was desired. Counseling provided by gender-affirming providers on sexual health was trusted and other healthcare providers were perceived to lack training on gender-inclusive care.

CONCLUSION

This study demonstrated that families and school educators did not provide sex education perceived to be applicable to transgender adolescents. Similarly, healthcare providers of transgender adolescents were perceived to not provide inclusive or comprehensive medical care in comparison to physicians who routinely provide gender-affirming care. Gaps in education and healthcare could be improved with sex education outreach or training for families and school educators as well as the development and implementation of professional competencies for pediatricians on transgender adolescent healthcare.

Differences/Disorders of Sex Development: Medical Conditions at the Intersection of Sex and Gender

Defined as congenital conditions in which development of chromosomal, gonadal, or anatomic sex is atypical, differences or disorders of sex development (DSDs) comprise many discrete diagnoses ranging from those associated with few phenotypic differences between affected and unaffected individuals to those where questions arise regarding gender of rearing, gonadal tumor risk, genital surgery, and fertility. Controversies exist in numerous areas including how DSDs are conceptualized, how to refer to the set of conditions and those affected by them, and aspects of clinical management that extend from social media to legislative bodies, courts of law, medicine, clinical practice, and scholarly research in psychology and sociology. In addition to these aspects, this review covers biological and social influences on psychosocial development and adjustment, the psychosocial and psychosexual adaptation of people born with DSDs, and roles for clinical psychologists in the clinical management of DSDs. Expected final online publication date for the Annual Review of Clinical Psychology, Volume 18 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

A Year Through the COVID-19 Pandemic: Deleterious Impact of Hormonal Contraception on Psychological Distress in Women

BACKGROUND

Women are more at risk than men of suffering from psychological distress during disease outbreaks. Interestingly, no biological factors have been studied to explain this disparity in such contexts. Sex hormone variations induced by hormonal contraceptives (HC) have been associated with mental health vulnerabilities. However, most studies have examined current effects of HC without considering whether a chronic modulation of sex hormone levels could induce long-lasting effects that persist after HC cessation.

OBJECTIVES

To date, the role of HC on psychological health in women during a disease outbreak is still unknown. We aimed to investigate both current and long-term effects of HC on psychological distress throughout the COVID-19 pandemic.

METHOD

At four time points during the COVID-19 pandemic (June 2020, September 2020, December 2020, March 2021), we collected self-reported data on psychological distress, assessing symptoms of post-traumatic stress [via the Impact of Event Scale-Revised (IES-R)], symptoms of depression, anxiety, and stress [via the Depression Anxiety Stress Scales (DASS-21)]. Linear mixed models were first used to compare men (n = 49), naturally cycling women (n = 73), and women using HC (n = 32) across time. To examine long-lasting effects of HC, exploratory analyses were restricted to women, comparing current HC users (n = 32), past users (n = 56), and never users (n = 17).

RESULTS

The first model revealed that women taking HC reported stable post-traumatic stress symptoms across time, compared to naturally cycling women and men who showed a significant decrease from T1 to T2. HC users also reported greater DASS-21 total scores over time. Moreover, HC users reported higher stress and anxiety symptoms than men. In the second model, results showed that past HC users had similar anxiety levels as current HC users. These two groups reported significantly more anxiety symptoms than never users.

CONCLUSION

HC users report increased distress during the pandemic relative to naturally cycling women and men. Our results also suggest a long-lasting effect of HC intake, highlighting the importance of considering both the current use of HC and its history. This could provide some insight into potential avenues for explaining why some women are prone to higher psychological distress than men.

Sex and gender difference in cognitive and behavioral studies in developmental age: An introduction

This paper introduces a special issue focused on sex and gender (s/g) cognitive/behavioral differences at developmental ages providing an overview of this multifaceted and debated topic. It will provide a description of the biological systems that are strongly interconnected to generate s/g differences, that is, genetic determinants, sex hormones, differences in brain structure, organization, and/or function, inherited or modifiable under environmental pressures. Developmental studies are rare. Some addressed whether s/g differences in cognitive/behavioral characteristics are evident early in life and are consistent throughout development, entailing that s/g differences can follow the evolving steps in girls and boys in different domains. The data are far from being homogeneous and consistent about s/g difference in language, social skills, and visuo/spatial abilities. The differences are small, often with overlapping performances, similar to what is seen in adulthood. Given that several variables and the interactions between them are implicated, further longitudinal studies adopting adequate assessment tools, very large size multicultural samples stratified in different, well-sized and precise age groups, considering biological and sociocultural variables, are needed. Due to the complexity of the issue, there is still the need to support and adopt an s/g difference approach also in cognitive and behavioral studies at developmental ages. Finally, these studies have not only scientific importance and relevant cultural, anthropological, and social implications, but are also useful for pedagogical programming as well as for the study of the different susceptibility to develop CNS diseases and consequently to promote different therapies and treatments.

Masculinity and Lying

Dishonesty in communication has important economic implications. The standing literature has shown that lying is less pervasive than predicted by standard economic theory. We explore whether biology can help to explain this behavior. In a sample of men, we study whether masculine traits are related to (dis)honesty in a sender-receiver game. We study three masculine physical traits: the second-to-fourth digit ratio, facial morphometric masculinity and the facial width-to-height ratio. These biomarkers display significant associations with lying and deception in the game. We also explore the extent to which these effects operate through social preferences or through beliefs about the behavior of receivers.

Premenstrual dysphoric disorder is associated with the longer length from clitoris to urethra

Background

Premenstrual dysphoric disorder (PMDD) is a common, recently recognized, psychiatric condition among reproductive women, reflecting abnormal responsivity to ovarian steroids. Moreover, the potential organizational effect of prenatal sex hormones during PMDD has got attentions, but there have been considerably less of researches on this topic. The aim of this research was to investigate the possible role of prenatal androgen in the PMDD.

Methods

Anogenital distance (AGD), the distance between a woman’s clitoris and her urethral meatus (CUMD), left and right 2D:4D ratios were measured in 77 subjects (25 patients with PMDD), as these anthropometric indicators are considered to indirectly reflect prenatal androgen exposures in utero.

Results

Patients with PMDD had a longer CUMD than controls (25.03 ± 4.73 vs. 22.07 ± 4.30, P = 0.008), while there were no significant difference between PMDD group and control group in the AGD and right and left 2D:4D ratios.

Conclusion

Atypical high prenatal androgen exposure might predispose individuals to be susceptible to PMDD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-021-01403-4.

Development of sex differences in the human brain

Sex differences in brain anatomy have been described from early childhood through late adulthood, but without any clear consensus among studies. Here, we applied a machine learning approach to estimate 'Brain Sex' using a continuous (rather than binary) classifier in 162 boys and 185 girls aged between 5 and 18 years. Changes in the estimated sex differences over time at different age groups were subsequently calculated using a sliding window approach. We hypothesized that males and females would differ in brain structure already during childhood, but that these differences will become even more pronounced with increasing age, particularly during adolescence. Overall, the classifier achieved a good performance, with an accuracy of 80.4% and an AUC of 0.897 across all age groups. Assessing changes in the estimated sex with age revealed a growing difference between the sexes with increasing age. That is, the very large effect size of d = 1.2 which was already evident during childhood increased even further from age 11 onward, and eventually reached an effect size of d = 1.6 at age 17. Altogether these findings suggest a systematic sex difference in brain structure already during childhood, and a subsequent increase of this difference during adolescence.

Evidence and Implications from a Natural Experiment of Prenatal Androgen Effects on Gendered Behavior

Sex and gender are key to people's lives, and are the focus of scientific and popular interest and controversy. Sex-related psychological characteristics reflect more than socialization; they are influenced by sex hormones present during sensitive periods of development, particularly prenatal androgens. Studies of females with congenital adrenal hyperplasia (CAH) show how prenatal androgens affect behavior across the life span, with large effects on gendered activity interests and engagement, moderate effects on spatial abilities, and relatively small (or no) effects on gender identity, gender cognitions, and gendered peer involvement. In addition to showing the complexity of androgen effects on gendered behavior, studies of females with CAH provide an opportunity to test theories of gender development, understand how nature and nurture work together, and examine mechanisms of development. The implications of this work have often been misunderstood, so we consider what it means - and does not mean - for biology to influence gender-related behavior.

Percentile values for serum levels of vitamins A and D in Iranian children and adolescents: The CASPIAN-V study

OBJECTIVES

The reference values to determine vitamin A and D deficiency may vary based on ethnicity, age, and region of residence. The aim of this study was to determine the reference interval of circulating vitamin A and D levels among Iranian children and adolescents based on sex, age, and region of residence.

METHODS

This nationwide cross-sectional study was performed with 2596 students 7 to 18 y of age from the CASPIAN-V (Childhood and Adolescence Surveillance and Prevention of Adult Non- communicable disease) study. A parametric method was used to define the age-specific reference values by obtaining smooth centile curves and explicit formulae for the centile estimates and SD scores for both sexes and regions of residence.

RESULTS

Significant differences were found between the residents of rural and urban regions in terms of serum 25-hydroxyvitamin D [25(OH)D] and retinol concentration (P < 0.05). Boys (27 ± 8 versus 26.04 ± 10, P = 0.009). Children ages 7 to 12 y had higher serum 25(OH)D concentration than 13- to 18-y-old adolescents (26.96 ± 8 versus 26.04 ± 10, P = 0.007). The estimated reference interval for circulating 25(OH)D levels corresponding to the range between the 5th and 95th percentiles were 11.45 to 48.40 ng/mL in boys and 9.51 to 47.69 ng/mL in girls. Estimated reference intervals for serum retinol concentration among boys and girls corresponding to the 5th and 95th percentiles were 0.58 to 3.38 and 0.58 to 4.52, respectively. There were significant variations in both retinol and 25(OH)D concentrations across different age groups.

CONCLUSION

This study established the reference intervals for circulating 25(OH)D and retinol levels in Iranian adolescents and children in different age groups based on sex and region.

Markers of Prenatal Androgen Exposure Correlate With Online Sexual Compulsivity and Erectile Function in Young Men

Pornography addiction and sexual dysfunction are increasingly prevalent in young men. Previous studies suggest that prenatal androgen exposure plays a role in addiction and sexual functionality. Here, we tested whether lower second-to-fourth finger length ratio (2D:4D) and later age at spermarche, both putative indicators of higher androgen levels in utero, correlate with online sexual compulsivity (OSC scale of ISST), erectile function (IIEF-5), and ejaculatory control (PEPA) in 4,370 young men (age IQR: 25-26 years) of the Cohort Study on Substance Use Risk Factors. Statistical analyses revealed that lower 2D:4D correlated with higher scores on the OSC scale. Moreover, higher age at spermarche correlated with higher OSC scores and decreased erectile function. Interestingly, OSC severity, but not the frequency of pornography use, correlated negatively with erectile function and ejaculatory control. This is the first study to associate two independent proxies of prenatal testosterone level with OSC. These findings provide novel insight into intrauterine predisposition of sexual behavior and related sexual function in adulthood.

2D:4D Digit Ratios in Adults with Gender Dysphoria: A Comparison to Their Unaffected Same-Sex Heterosexual Siblings, Cisgender Heterosexual Men, and Cisgender Heterosexual Women

We compared gender dysphoria (GD) patients and their same-sex siblings in terms of their 2D:4D ratios, which may reflect prenatal exposure to androgen, one of the possible etiological mechanisms underlying GD. Sixty-eight GD patients (46 Female-to-Male [FtM]; 22 Male-to-Female [MtF]), 68 siblings (46 sisters of FtMs; 22 brothers of MtFs), and 118 heterosexual controls (62 female; 56 male) were included in the study. FtMs were gynephilic and MtFs were androphilic. We found that 2D:4D ratios in the both right hand (p < .001) and the left hand (p = .003) were lower in male controls than in female controls. Regarding right hands, FtM GD patients had lower 2D:4D ratios than female controls (p < .001) but their ratios did not differ from those of their sisters or male controls. FtM GD patients had no significant difference in their left-hand 2D:4D ratios compared to their sisters or female and male controls. While there was no significant difference in right hands between FtM's sisters and male controls, left-hand 2D:4D ratios were significantly higher in FtM's sisters (p = .017). MtF GD patients had lower right-hand 2D:4D ratios than female controls (p <.001), but their right-hand ratios did not differ from those of their brothers and male controls. There was no significant difference in left-hand 2D:4D ratios between MtF GD patients, and their brothers, or female and male controls. FtM GD patients showed significantly masculinized right-hand 2D:4D ratios, while there was no evidence of feminization in MtF GD patients.

Intrauterine testosterone exposure and depression risk in opposite-sex and same-sex twins, a Danish register study

BACKGROUND

Males have a lower prevalence of depression than females and testosterone may be a contributing factor. A comparison of opposite-sex and same-sex twins can be used indirectly to establish the role of prenatal testosterone exposure and the risk of depression. We therefore aimed to explore differences in depression risk using opposite-sex and same-sex twins.

METHODS

We included 126 087 opposite-sex and same-sex twins from the Danish Twin Registry followed in nationwide Danish registers. We compared sex-specific incidences of depression diagnosis and prescriptions of antidepressants between opposite-sex and same-sex twins using Cox proportional hazard regression.

RESULTS

During follow-up, 2664 (2.1%) twins were diagnosed with depression and 19 514 (15.5%) twins had purchased at least one prescription of antidepressants. First, in male twins, we found that the opposite-sex male twins had the same risk of depression compared to the same-sex male twins {hazard ratio (HR) = 1.01 [95% confidence interval (CI) 0.88-1.17)]}. Revealing the risk of use of antidepressants, the opposite-sex male twins had a slightly higher risk of 4% (HR = 1.04 (95% CI 1.00-1.11)) compared with the same-sex male twins. Second, in the female opposite-sex twins, we revealed a slightly higher, however, not statistically significant risk of depression (HR = 1.08 (95% CI 0.97-1.29)) or purchase of antidepressants (HR = 1.01 (95% CI 0.96-1.05)) when compared to the same-sex female twins.

CONCLUSIONS

We found limited support for the hypothesis that prenatal exposure to testosterone was associated with the risk of depression later in life.

Prenatal exposure to bisphenol A and autistic- and ADHD-related symptoms in children aged 2 and5 years from the Odense Child Cohort

BACKGROUND

Bisphenol A (BPA) is a non-persistent chemical with endocrine disrupting abilities used in a variety of consumer products. Fetal exposure to BPA is of concern due to the elevated sensitivity, which particularly relates to the developing brain. Several epidemiological studies have investigated the association between prenatal BPA exposure and neurodevelopment, but the results have been inconclusive.

OBJECTIVE

To assess the association between in utero exposure to BPA and Attention Deficit/Hyperactivity Disorder (ADHD-) symptoms and symptoms of Autism Spectrum Disorder (ASD) in 2 and 5-year old Danish children.

METHOD

In the prospective Odense Child Cohort, BPA was measured in urine samples collected in gestational week 28 and adjusted for osmolality. ADHD and ASD symptoms were assessed with the use of the ADHD scale and ASD scale, respectively, derived from the Child Behaviour Checklist preschool version (CBCL/1½-5) at ages 2 and 5 years. Negative binomial and multiple logistic regression analyses were performed to investigate the association between maternal BPA exposure (continuous ln-transformed or divided into tertiles) and the relative differences in ADHD and ASD problem scores and the odds (OR) of an ADHD and autism score above the 75th percentile adjusting for maternal educational level, maternal age, pre-pregnancy BMI, parity and child age at evaluation in 658 mother-child pairs at 2 years of age for ASD-score, and 427 mother-child pairs at 5 years of age for ADHD and ASD-score.

RESULTS

BPA was detected in 85.3% of maternal urine samples even though the exposure level was low (median 1.2 ng/mL). No associations between maternal BPA exposure and ASD at age 2 years or ADHD at age 5 years were found. Trends of elevated Odds Ratios (ORs) were seen among 5 year old children within the 3rd tertile of BPA exposure with an ASD-score above the 75th percentile (OR = 1.80, 95% CI 0.97,3.32), being stronger for girls (OR = 3.17, 95% CI 1.85,9.28). A dose-response relationship was observed between BPA exposure and ASD-score at 5 years of age (p-trend 0.06) in both boys and girls, but only significant in girls (p-trend 0.03).

CONCLUSION

Our findings suggest that prenatal BPA exposure even in low concentrations may increase the risk of ASD symptoms which may predict later social abilities. It is therefore important to follow-up these children at older ages, measure their own BPA exposure, and determine if the observed associations persist.

Emotional stability is related to 2D:4D and social desirability in women: Possible implications on subjective well-being and psychopathology

Emotional stability-Neuroticism is a complex construct influenced by genetics and environmental factors. Women tend to exhibit higher neuroticism scores than men, which may be associated with an increased risk of suffering from some common mental conditions. Some authors have pointed out the influence of sex hormones, since they induce sexual differentiation of the brain that can lead to sex-specific behaviors. 2D:4D digit ratio is commonly used as a marker of prenatal sex hormones. In this study we analyzed whether there was an association between 2D:4D and personality measured through the BFQ in a homogeneous sample of 101 young women college students. We found a positive association between 2D:4D and emotional stability, as well as with its subdimensions emotion control and impulse control. This association could be quadratic and nonlinear. However, no association was found with the other four dimensions. We also measured anxiety, depression and global life satisfaction, variables related to neuroticism. We observed that emotional stability is positively associated to social desirability and global life satisfaction, and negatively related to anxiety and depression. On the other hand, we did not find any association between 2D:4D and anxiety, depression, and global life satisfaction. These results can be linked to other aspects such as subjective well-being and psychopathological symptoms. This study may help to better understand how these constructs are related and could lead to future projects to elucidated how these variables influence personality.

High emotional experience during autobiographical retrieval in women with Korsakoff syndrome

INTRODUCTION

In this exploratory study, we investigated gender differences regarding autobiographical memory in KS.

METHOD

We invited 33 patients with KS and 35 matched control participants to retrieve autobiographical memories and, afterward, to rate mental time travel during retrieval, emotional value and importance of memories.

RESULTS

Analysis demonstrated lower specificity (i.e., lower ability to retrieve memories situated in a specific time and space), mental time travel, and importance in patients with KS compared to control participants. Analysis also demonstrated no significant difference between patients with KS and control participants regarding emotion. Critically, analysis demonstrated no significant differences neither women and men with KS, nor between women and men in the control group, regarding autobiographical specificity, mental time travel, or importance. However, women with KS attributed higher emotional value for memories compared to men with KS, and the same results were observed in the control group.

DISCUSSION

These findings demonstrate that the higher emotional experience during autobiographical retrieval, as observed in the general population, can also be observed in KS.

No evidence for a difference in 2D:4D ratio between youth with elevated prenatal androgen exposure due to congenital adrenal hyperplasia and controls

The second-to-fourth digit ratio (2D:4D) has been associated with sexual dimorphism, with a lower 2D:4D in males. A large body of research has relied on the 2D:4D as a proxy for prenatal androgen exposure, and includes reports of relationships between 2D:4D and a wide range of human traits. Here, we examine the validity of the 2D:4D proxy by studying the association between 2D:4D and classical Congenital Adrenal Hyperplasia (CAH) due to 21-hydroxylase deficiency, a condition characterized by excessive prenatal exposure to androgens during most of the gestational period. To this end, we retrospectively examine 513 serial radiographs of the left hand obtained clinically in 90 youth with classical CAH (45 female) and 70 control youth (31 female). Replicating previous reports, we observe associations of the 2D:4D with sex (lower 2D:4D in males) and age (increase of 2D:4D through development). However, we find no evidence for differences in 2D:4D between CAH and controls (full sample: β = -0.001 (-0.008, 0.006); females: β = -0.004 [-0.015, 0.007]; males: β = 0.001, [-0.008, 0.011]). Although our findings do not rule out a small association between the 2D:4D and CAH, they cast doubt on the usefulness of the 2D:4D as a biomarker for prenatal androgen exposure in behavioral research.

Men, women and STEM: Why the differences and what should be done?

It is a well-known and widely lamented fact that men outnumber women in a number of fields in STEM (science, technology, engineering and maths). The most commonly discussed explanations for the gender gaps are discrimination and socialization, and the most common policy prescriptions target those ostensible causes. However, a great deal of evidence in the behavioural sciences suggests that discrimination and socialization are only part of the story. The purpose of this paper is to highlight other aspects of the story: aspects that are commonly overlooked or downplayed. More precisely, the paper has two main aims. The first is to examine the evidence that factors other than workplace discrimination contribute to the gender gaps in STEM. These include relatively large average sex differences in career and lifestyle preferences, and relatively small average differences in cognitive aptitudes – some favouring males, others favouring females – which are associated with progressively larger differences the further above the average one looks. The second aim is to examine the evidence suggesting that these sex differences are not purely a product of social factors but also have a substantial biological (i.e. inherited) component. A more complete picture of the causes of the unequal sex ratios in STEM may productively inform policy discussions.

Sex continuum in the brain and body during adolescence and psychological traits

Many traits of the brain and body show marked sex differences, but the distributions of their values overlap substantially between the two sexes. To investigate variations associated with biological sex, beyond binary differences, we create continuous sex scores capturing the inter-individual variability in phenotypes. In an adolescent cohort (n = 1,029; 533 females), we have generated three sex scores based on brain-body traits: 'overall' (48 traits), 'pubertal' (26 traits) and 'non-pubertal' (22 traits). We then conducted sex-stratified multiple linear regressions (adjusting for age) using sex scores to test associations with sex hormones, personality traits and internalizing-externalizing behaviour. Higher sex scores (that is, greater 'femaleness') were associated with lower testosterone in males only, as well as lower extraversion, higher internalizing and lower externalizing in both sexes. The associations with testosterone, internalizing and externalizing were driven by pubertal sex scores, underscoring the importance of adolescence in shaping within-sex individual variability.