Variations in gender identity and sexual orientation of university students.

Background: Previous studies have shown that a small percentage of people in the general population have atypical gender identity and/or sexual orientation. Aim: This study aimed to explore variations in gender identity and sexual orientation in university students and determine genetic factors associated with these variations. Methods: Deviations from complete gender congruence and exclusive heterosexual orientation in 736 Japanese university students were quantitatively assessed with self-assessment questionnaires. Next, we conducted genetic tests for 80 participants who showed relatively low gender identity scores and/or atypical sexual orientation. These genetic tests consisted of repeat number analysis of the androgen receptor gene (AR) and a SKAT-O: an optimal unified sequence kernel association test, which is an exome-based rare variant association study. The results of the genetic tests were compared with the Japanese reference data and the results of our 637 control samples. Outcomes: We calculated the gender identity and sexual orientation scores of all participants and analyzed the molecular data of 80 selected participants. Results: The gender identity scores of 736 participants were broadly distributed: only ~15% of natal males and ~5% of natal females had the maximum score that corresponds to complete gender congruence. The sexual orientation scores also varied: ~80% of natal males and ~60% of natal females showed exclusive heterosexual orientation. We found no association between gender characteristics and AR repeat numbers. The SKAT-O showed that rare damaging variants of TDRP and 3 other genes were more common in the 80 participants than in the control group. Clinical Implications: Our data support the view that gender is a phenotypic continuum rather than a binary trait. Strength and Limitations: This study quantitatively assessed the gender characteristics of a large cohort of university students. Moreover, we conducted systematic screening for genetic factors associated with gender variations. The weaknesses of the study were the limited analytic power of the questionnaires, the relatively small sample for molecular analyses, and incomplete clinical information and relatively advanced ages of the control group. Conclusion: This study revealed significant variations in gender identity and sexual orientation in university students, which may be partly associated with variants in TDRP or other genes.

Current situation and clinical burden of pediatricians for children with eating disorders during the COVID-19 pandemic.

During the COVID-19 pandemic, the incidence of eating disorders (ED) has increased not only in Japan but also worldwide. This online survey for pediatricians showed that caregivers tend to visit specific pediatric institutions or child psychiatry departments when children under junior high school age develop eating disorders. There are few pediatric institutions regarding treatment acceptance for children with ED. Of the 34 respondents, 16 (47.1%) answered that the number of visits for children with eating disorders had "stayed the same", one answered it had "decreased" and 17 (50.0%) answered it had "increased" or "increased very much". In addition, 28 of the 34 respondents (82.3%) experienced difficulties with psychotherapy for children with ED. For treating children with ED, pediatricians usually conducted physical examination and have some clinical burden. ED are increasing in the COVID-19 pandemic. Because children with severe ED need to be hospitalized, child and adolescent psychiatric wards are overcrowded and some children with other mental disorders can't be admitted.

[Does Early Olaparib Administration Improve Prognosis in Patients with HER2-Negative Metastatic Breast Cancer and BRCA1 and/or BRCA2 Pathogenic Variants?-A Case Report].

We herein describe our experience with patients who had been diagnosed with BRCA1/2 pathogenic variants and metastatic breast cancer. Three patients who experienced postoperative recurrences had received chemotherapy before recurrence, while an additional patient with stage Ⅳ disease at diagnosis required chemotherapy before olaparib administration. Prior anthracycline and/or taxane-based therapies needed prior to administration of poly(adenosine diphosphate ribose) polymerase inhibitors might still be controversial in terms of patient benefits.

Evaluating the daily life of child and adolescent psychiatric outpatients during temporary school closure over COVID-19 pandemic: A single-center case-control study in Japan.

This study evaluated the clinical characteristics of mental health of child and adolescent psychiatric patients during temporary school closure throughout the coronavirus 2019 (COVID-19) pandemic in Japan using the Questionnaire - Children with Difficulties (QCD) and other useful psychological rating scales. The participants were those who visited the Department of Child and Adolescent Psychiatry, Kohnodai Hospital. From those 1,463 participants, case and control groups were selected: 92 patients who visited the hospital during the temporary school closure from March 2020 to May 2020 (case group) and randomly sampled sex- and age-matched 92 patients during the pre-COVID period from April 2017 to March 2020 (control group). QCD is a parent-assessed questionnaire designed to evaluate the difficulties of children along the course of a day, right from waking up in the morning to retiring to bed at night. Lower scores indicate stronger difficulties. QCD scores were compared between the two groups in each of the following age groups: elementary school (6-12 years of age) and junior high school (12-15 years of age). In elementary school students, scores "during school" of QCD indicating functioning or disabilities during school hours were 3.31 ± 2.52 and 4.52 ± 2.33 in case group and control group, respectively (p < 0.05). In junior high school students, scores "Attention-Deficit Hyperactivity Disorder Rating Scale (ADHD-RS)" indicating ADHD symptoms were 16.78 ± 12.69 and 11.80 ± 10.40 in case group and control group, respectively (p < 0.05). The findings suggest that the closure of schools due to the pandemic might worsen difficulties among elementary school patients, and hyperactivity and impulsivity might increase among junior high school patients. The long-term impact of stress caused by school closure on child and adolescent psychiatric patients needs to be investigated in the future.

Effect of Human Cytochrome P450 2D6 Polymorphism on Progesterone Hydroxylation.

BACKGROUND AND OBJECTIVES: Herein, hydroxylation activities at the 6ß-position and 21-position of progesterone mediated by human cytochrome P450 (CYP) 2D6 and its variants and the effects of psychotropic drugs on these hydroxylation activities were compared to clarify whether CYP2D6 polymorphisms and psychotropic drugs impact neurosteroid levels in the brain. METHODS: Progesterone was incubated with CYP2D6.1, CYP2D6.2 (Arg296Cys, Ser486Thr), CYP2D6.10 (Pro34Ser, Ser486Thr), and CYP2D6.39 (Ser486Thr) in the absence or presence of typical psychotropic drugs (fluvoxamine, fluoxetine, paroxetine, fluphenazine, and milnacipran) and endogenous steroids (testosterone and cortisol). Then, 6ß- and 21-hydroxyprogesterone levels were determined by high-performance liquid chromatography. RESULTS: Although the Michaelis-Menten constants (Km) for progesterone 6ß- and 21-hydroxylation reactions mediated by the different CYP2D6 variants were similar, the maximal velocity (Vmax) values of the reactions mediated by CYP2D6.1 and CYP2D6.2 were the highest, followed by those mediated by CYP2D6.39 and CYP2D6.10. Thus, the of progesterone 6ß- and/or 21-hydroxylation reactions mediated by CYP2D6.1 and CYP2D6.2 showed the highest Vmax/Km values, followed by the reactions mediated by CYP2D6.39. All investigated compounds inhibited progesterone 21-hydroxylation mediated by CYP2D6 variants at high concentrations. Interestingly, at low concentrations, fluoxetine increased progesterone 21-hydroxylation mediated by CYP2D6.1, but not that mediated by CYP2D6.2 or CYP2D6.10. In addition, the Km value for CYP2D6.2 was elevated in the presence of fluoxetine, whereas the value for CYP2D6.1 was unaltered; however, Vmax values of both CYP2D6.1 and CYP2D6.2 were increased. Paroxetine competitively inhibited CYP2D6.1- and CYP2D6.2-mediated progesterone 21-hydroxylation. CONCLUSIONS: These results suggest that CYP2D6 polymorphism can affect the stimulation/inhibition of progesterone 21-hydroxylation.

Prevalence of common aneuploidy in twin pregnancies.

The incidence of chromosomal abnormalities in twin pregnancies is not well-studied. In this retrospective study, we investigated the frequency of chromosomal abnormalities in twin pregnancies and compared the incidence of chromosomal abnormalities in dichorionic diamniotic (DD) and monochorionic diamniotic (MD) twins. We used data from 57 clinical facilities across Japan. Twin pregnancies of more than 12 weeks of gestation managed between January 2016 and December 2018 were included in the study. A total of 2899 and 1908 cases of DD and MD twins, respectively, were reported, and the incidence of chromosomal abnormalities in one or both fetuses was 0.9% (25/2899) and 0.2% (4/1908) in each group (p = 0.004). In this study, the most common chromosomal abnormality was trisomy 21 (51.7% [15/29]), followed by trisomy 18 (13.8% [4/29]) and trisomy 13 (6.9% [2/29]). The incidence of trisomy 21 in MD twins was lower than that in DD twins (0.05% vs. 0.5%, p = 0.007). Trisomy 21 was less common in MD twins, even when compared with the expected incidence in singletons (0.05% vs. 0.3%, RR 0.15 [95% CI 0.04-0.68]). The risk of chromosomal abnormality decreases in twin pregnancies, especially in MD twins.

Lower systolic blood pressure levels in early pregnancy are associated with a decreased risk of early-onset superimposed preeclampsia in women with chronic hypertension: a multicenter retrospective study.

To clarify the impact of blood pressure (BP) management ranges on pregnancy outcomes, we conducted a multicenter retrospective analysis of 215 women with singleton pregnancies diagnosed with essential hypertension either before or within 14 weeks of gestation. Patients were classified according to systolic BP (sBP; <130, 130-139, 140-159, and ≥160 mmHg) or diastolic BP (dBP; <80, 80-89, 90-109, and ≥110 mmHg) at 8-11, 12-15, and 16-19 weeks of gestation. The risk of early-onset superimposed preeclampsia and small-for-gestational-age neonates was assessed in each BP group. Moreover, a subgroup analysis was performed in 144 eligible patients whose BP was measured at both 12-13 and 14-15 weeks of gestation. At 16-19 weeks of gestation, higher sBP significantly increased the incidence of early-onset superimposed preeclampsia (13.3%, 24.6%, 32.2% and 75.0%, respectively) and small-for-gestational-age neonates (6.0%, 13.1%, 16.9% and 50.0%, respectively). Multivariate logistic regression analyses showed that women with sBP < 130 mmHg at 16-19 weeks of gestation had a significantly lower risk of early-onset superimposed preeclampsia than women with sBP of 140-159 mmHg. Subgroup analyses also showed that even at 14-15 weeks of gestation, sBP < 130 mmHg was associated with a significantly lower risk of early-onset superimposed preeclampsia than an sBP of 140-159 mmHg. In conclusion, sBP < 130 mmHg within 14 weeks of gestation reduced the risk of developing early-onset superimposed preeclampsia in women with chronic hypertension.

Case-control study on clinical characteristics of child and adolescent psychiatric outpatients with child-to-parent violence.

OBJECTIVES: To the best of our knowledge, no case-control study on child and adolescent psychiatric outpatients has investigated the clinical characteristics of patients with child-to-parent violence (CPV). The current study aimed to evaluate the clinical characteristics of child and adolescent psychiatric patients with CPV. SETTING AND PARTICIPANTS: This research included child and adolescent psychiatric patients who were aged 10-15 years during their initial consultation. The participants were allocated to one of two groups: children with CPV (CPV group, n=109) and without CPV (non-CPV group, n=713). OUTCOME MEASURES: This study analysed data including age, sex, diagnostic classification of the primary diagnosis, antisocial behaviour, suicidal attempt or self-harm and refusal to attend school. Moreover, a history of abuse by parents was investigated. Psychological rating scales such as the Spence Children's Anxiety Scale, Depression Self-Rating Scale for Children, Tokyo Autistic Behavior Scale, Attention-deficit/Hyperactivity Disorder-Rating Scale and Oppositional Defiant Behavior Inventory were used. RESULTS: Of 822 patients who sought consultation in our department, 109 (13.26%) were included in the CPV group during the first consultation. Compared with the non-CPV group, the CPV group had significantly higher proportions of patients who experienced physical abuse, psychological abuse and who witnessed violence between parents. Meanwhile, the proportion of patients with neurodevelopmental disorders was significantly higher in the CPV group than in the non-CPV group. Regarding developmental characteristics, impulsivity might be correlated with CPV. Moreover, violence and behavioural problems outside of home were associated with CPV. CONCLUSIONS: In patients with CPV who sought consultation, the findings of the current study should be considered to understand invisible side and to facilitate the use of appropriate treatment approaches. However, a prospective study should be performed to investigate the causality between CPV and clinical characteristics.

Care for children's mental health during the COVID-19 pandemic in Japan.

COVID-19 causes very serious issues all over the world. In Japan, the number of new infections in Tokyo exceeded 2,000 for the first time on 7 January 2021, and the situation is becoming increasingly serious. Japan is in the midst of its third big outbreak. Japanese society will face several challenges regarding children's mental health during the COVID-19 pandemic. In order to develop healthy minds in children, it is important to view the changes in children's minds in a positive light and promote their healthy emotional development while correctly fearing COVID-19. This sense of social stagnation and uncertainty is likely to increase feelings of insecurity and isolation among children. It is also important to prevent the repetition of child abuse in the home due to parental unemployment, alcohol problems, and reduced contact with non-family members in stay home and the recession as a result of COVID-19. During the pandemic, adults should be sensitive to the unusual behavior of children. We propose six suggestions of care for children during the COVID-19 pandemic.

Comparison of the Stimulatory and Inhibitory Effects of Steroid Hormones and α-Naphthoflavone on Steroid Hormone Hydroxylation Catalyzed by Human Cytochrome P450 3A Subfamilies.

The inhibitory and stimulatory effects of steroid hormones and related compounds on the hydroxylation activity at the 6ß-position of two steroid hormones, progesterone and testosterone, by CYP3A4, polymorphically expressed CYP3A5, and fetal CYP3A7 were compared to clarify the catalytic properties of the predominant forms of the human CYP3A subfamily. Hydroxylation activities of progesterone and testosterone by CYP3A4, CYP3A5, and CYP3A7 were estimated using HPLC. The Michaelis constants (Km) for progesterone 6ß-hydroxylation by CYP3A5 were markedly decreased in the presence of dehydroepiandrosterone (DHEA) and α-naphthoflavone (ANF), whereas progesterone and DHEA competitively inhibited testosterone 6ß-hydroxylation mediated by CYP3A4, and progesterone competitively inhibited CYP3A5-mediated activity, which was weaker than that for CYP3A4. ANF noncompetitively inhibited testosterone 6ß-hydroxylation mediated by both CYP3A4 and CYP3A5. Progesterone and testosterone 6ß-hydroxylation mediated by CYP3A7 was inhibited or unaffected by DHEA, pregnenolone, and ANF. These results suggested that DHEA and ANF stimulated progesterone 6ß-hydroxylation by CYP3A5 but not by CYP3A4 and CYP3A7; however, progesterone, DHEA, and ANF inhibited testosterone 6ß-hydroxylation mediated by all CYP3A subfamily members. The inhibitory/stimulatory pattern of steroid-steroid interactions is different among CYP3A subfamily members and CYP3A5 is the most sensitive in terms of activation among the CYP3A subfamily members investigated.

Comparison of steroid hormone hydroxylation mediated by cytochrome P450 3A subfamilies.

Hydroxylation activity at the 6ß-position of steroid hormones (testosterone, progesterone, and cortisol) by human cytochromes P450 (CYP) 3A4, polymorphic CYP3A5, and fetal CYP3A7 were compared to understand the catalytic properties of the major forms of human CYP3A subfamily. Testosterone, progesterone, and cortisol 6ß-hydroxylation activities of recombinant CYP3A4, CYP3A5, and CYP3A7 were determined by liquid chromatography. Michaelis constants (Km) for CYP3A7-mediated 6ß-hydroxylation of testosterone, progesterone, and cortisol were similar to those of CYP3A4 and CYP3A5. The maximal velocity (kcat) and kcat/Km values for CYP3A4 were the highest, followed by CYP3A5 and those for CYP3A7 were the lowest among three CYP3A subfamily members. A decrease in Km values for progesterone 6ß-hydroxylation by CYP3A4, CYP3A5, and CYP3A7 in the presence of testosterone was observed, and the kcat values for CYP3A5 gradually increased with increasing testosterone. This indicated that testosterone stimulated progesterone 6ß-hydroxylation by all three CYP3A subfamily members. However, progesterone inhibited testosterone 6ß-hydroxylation mediated by CYP3A4, CYP3A5, and CYP3A7. In conclusion, the kcat values, rather than Km values, for 6ß-hydroxylation of three steroid hormones mediated by CYP3A7 were different from those for CYP3A4 and CYP3A5. In addition, the inhibitory/stimulatory pattern of steroid-steroid interactions would be different among CYP3A subfamily members.

Impact of Organization and Career Commitment on Clinical Nursing Competency.

BACKGROUND: The majority of nurses are employed at medical institutions and acquire clinical competency through their work within their organization. Hands-on experience in the clinical setting is essential to enhance a nurse's clinical competence. The objective of this study was to determine the impact of commitment to the practical skills of nurses within Tottori prefecture. METHODS: We studied data from 916 nurses employed at 7 publicly-funded medical facilities (national and other public institutions). Data on basic information, clinical nursing competence, and commitment were collected via an anonymous self-administered questionnaire. RESULTS: A total of 672 valid questionnaires were analyzed. Mean clinical nursing competence scores showed a tendency to increase with years of experience. Scores increased from years 1 to 4, and then tended to plateau or decrease slightly thereafter up to around year 9. Mean commitment scores decreased from 1 to 2 years of experience to 3 to 4 years of experience. Other than "normative factors," mean scores tended to increase after 5 to 10 years of experience. Multiple regression analysis showed that "job involvement" at 1 to 2 years; "overall job satisfaction" at 5 to 9 years; "career commitment" at 10 to 19 years; and "job involvement" and "career commitment" at ≥ 20 years impacted results. No factors appeared to have an influence on nurses in their 3rd to 4th year of experience. CONCLUSION: Based on the concepts described above, self-assessment of nursing competence scores tended to improve with years of experience. Mean commitment scores tended to decrease after 3 to 4 years of experience and thereafter plateaued or increased. Organizational commitment has not clearly been shown to affect nursing competency, but the factors that affect this parameter changed with the length of experience. Results suggest support is needed in the 1st and 2nd years to help nurses adapt to the organization while in years 5 through 9, support that takes work-life balance into consideration is needed. This indicates support should change to meet the needs of each stage in a nurse's career. In years 3 to 4, it was suspected that the nurses' relationship with the organization weakened. Helping nurses forge a good relationship with their organization is believed to be effective in improving clinical competency in nurses with 5 or more years of experience.

Psychosocial Twin Cohort Studies in Japan: The Keio Twin Research Center (KoTReC).

The Keio Twin Research Center (KoTReC) was established in 2009 at Keio University to combine two longitudinal cohort projects - the Keio Twin Study (KTS) for adolescence and adulthood and the Tokyo Twin Cohort Project (ToTCoP) for infancy and childhood. KoTReC also conducted a two-time panel study of self-control and psychopathology in twin adolescence in 2012 and 2013 and three independent anonymous cross-sectional twin surveys (ToTcross) before 2012 - the ToTCross, the Junior and Senior High School Survey and the High School Survey. This article introduces the recent research designs of KoTReC and its publications.

Successful treatment with gefitinib after Stevens-Johnson syndrome associated with afatinib therapy in a patient with adenocarcinoma of the lung.

We report a case of a 65-year-old woman with stage IV lung adenocarcinoma who experienced Stevens-Johnson syndrome (SJS) during afatinib therapy. The patient received afatinib as the first-line therapy after the confirmation of harboring an exon 19 deletion mutation in the epidermal growth factor receptor (EGFR) gene. The patient presented with multiple erythematous papules mainly on the body trunk and thigh 32 days after afatinib administration. Subsequently, diffuse erosions of oral mucosa and purpuric macules with flat atypical targets emerged. Skin biopsy specimen showed the histology compatible with epidermal necrosis and the patient was diagnosed as having SJS. The symptoms of SJS were recovered by systemic steroid and immunoglobulin treatment. Gefitinib was administered as the third-line therapy after the second-line therapy with carboplatin plus pemetrexed had failed. Tumor shrinkage was obtained shortly and has been maintained without the recurrence of SJS. Rechallenge of tyrosine kinase inhibitor by gefitinib could be an alternative treatment option in patients who experienced SJS by afatinib.

Genetic and Environmental Influences on Traits of Gender Identity Disorder: A Study of Japanese Twins Across Developmental Stages.

The present study examined: (1) gender and age differences of mean gender identity disorder (GID) trait scores in Japanese twins; (2) the validity of the prenatal hormone transfer theory, which predicts that, in dizygotic (DZ) twin pairs, twins with an opposite-gender co-twin more frequently exhibit GID traits than twins with a same-gender co-twin; and (3) the magnitude of genetic and environmental influences on GID traits as a function of age and gender. Data from 1450 male twin pairs, 1882 female twin pairs, and 1022 DZ male-female pairs ranging from 3 to 26 years of age were analyzed. To quantify individual variances in GID traits, each participant completed four questionnaire items based on criteria for GID from the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR). Our most important findings were: (1) Japanese females exhibited GID traits more frequently than males and Japanese children exhibited GID traits less frequently than adolescents and adults (among females, the prevalence was 1.6 % in children, 10 % in adolescents, and 12 % in adults; among males, the prevalence was 0.5, 2, and 3 %, respectively); (2) the data did not support the prenatal hormone transfer theory for GID traits; and (3) a large part of the variance for GID traits in children was accounted for by familial factors; however, the magnitude was found to be greater in children than in adolescents or adults, particularly among females. This study suggests that although the prevalence is likely to increase, familial effects are likely to decrease as individuals age.

Two cohort and three independent anonymous twin projects at the Keio Twin Research Center (KoTReC).

The Keio Twin Research Center has conducted two longitudinal twin cohort projects and has collected three independent and anonymous twin data sets for studies of phenotypes related to psychological, socio-economic, and mental health factors. The Keio Twin Study has examined adolescent and adult cohorts, with a total of over 2,400 pairs of twins and their parents. DNA samples are available for approximately 600 of these twin pairs. The Tokyo Twin Cohort Project has followed a total of 1,600 twin pairs from infancy to early childhood. The large-scale cross-sectional twin study (CROSS) has collected data from over 4,000 twin pairs, from 3 to 26 years of age, and from two high school twin cohorts containing a total of 1,000 pairs of twins. These data sets of anonymous twin studies have mainly targeted academic performance, attitude, and social environment. The present article introduces the research designs and major findings of our center, such as genetic structures of cognitive abilities, personality traits, and academic performances, developmental effects of genes and environment on attitude, socio-cognitive ability and parenting, genes x environment interaction on attitude and conduct problem, and statistical methodological challenges and so on. We discuss the challenges in conducting twin research in Japan.

The relationship between second-to-fourth digit ratio and female gender identity.

INTRODUCTION: Gender identity and the second-to-fourth finger length ratio (2D : 4D) are discriminative between the sexes. However, the relationship between 2D : 4D and gender identity disorder (GID) is still controversial. AIM: The aim of this study is to investigate the relationship between 2D : 4D and score on the Gender Identity Scale (GIS) in female-to-male (FtM) GID subjects. METHODS: Thirty-seven GID-FtM with testosterone replacement therapy from our clinic were included in this study. As controls, 20 male and 20 female volunteers participated from our institution (medical doctors and nurses). We photocopied left and right hands of the participants and measured the second and fourth finger lengths. Gender identity was measured with the GIS. MAIN OUTCOME MEASURES: 2D : 4D digit ratio and GIS in male, female, and GID-FtM subjects. RESULTS: The 2D : 4D (mean ± standard deviation) in male, female, and GID-FtM were 0.945 ± 0.029, 0.999 ± 0.035, and 0.955 ± 0.029 in right hand and 0.941 ± 0.024, 0.979 ± 0.040, and 0.954 ± 0.036 in left hand, respectively. The 2D : 4D was significantly lower in male controls in both hands and GID-FtM in the right hand than in female controls (P < 0.05, analysis of variance). Multiple linear regression analysis revealed that "consistent gender identity" score in the higher domain in GIS and "persistent gender identity" score in the lower domain are statistically significant variables correlating with 2D : 4D in the right hands among biological females. CONCLUSIONS: The finger length ratio 2D : 4D in GID-FtM was significantly lower than in female controls in the right hand in this study. 2D : 4D showed a positive correlation with GIS score. Because 2D : 4D influences are assumed to be established in early life and to reflect testosterone exposure, our results suggest a relationship between GID-FtM and perinatal testosterone.

The second to fourth digit ratio (2D:4D) in a Japanese twin sample: heritability, prenatal hormone transfer, and association with sexual orientation.

The second to fourth digit ratio has been argued to reflect prenatal hormonal influences and is reportedly associated with various psychological and behavioral traits, such as sexual orientation, cognitive abilities, and personality. We examined genetic and environmental influences on the second to fourth digit ratio (2D:4D) using a Japanese twin sample (N=300). The genetic analysis showed substantial additive genetic influences for both right and left hand 2D:4D. The rest of the variance was explained mainly by environmental influences not shared within twin pairs. These findings were, in general, in accordance with preceding studies with primarily Caucasian twin samples. The bivariate genetic analysis revealed that the additive genetic influences were largely shared between the right and left hand, while the non-shared environmental influences were largely unique to each hand. Results from a comparison of opposite-sex and same-sex twins were not significant, although they were in the predicted direction according to the prenatal hormone transfer hypothesis. Female monozygotic twin pairs discordant in sexual orientation showed significant within-pair differences in left hand 2D:4D, where non-heterosexual twins had lower (more masculinized) 2D:4D. In addition, we found that non-heterosexual male MZ twins had larger (more feminized) 2D:4D than their heterosexual co-twins. These results suggest the existence of non-shared environmental influences that affect both 2D:4D and sexual orientation.

Implicit and explicit associations in the fear structure of social anxiety.

Summary.-Implicit associations in the fear structure of social anxiety were investigated and their relations with explicit associations were examined in the present study. The Implicit Association Test was used to assess implicit associations. Individuals scoring High (n = 26) and Low (n = 18) on Social Anxiety completed two forms of the Implicit Association Test and rated the probability and cost of negative social outcomes. Analyses showed an implicit association between anxiety responses and negative evaluations was more strongly formed in the High Social Anxiety group than in the Low Social Anxiety group. Furthermore, relations between implicit associations and explicit measures were minimal. These findings suggested that the Implicit Association Test is suitable for the assessment of implicit associations in the fear structure of social anxiety, and that implicit associations of social anxiety are relatively independent of explicit associations.