Detransition and Desistance Among Previously Trans-Identified Young Adults

Persons who have renounced a prior transgender identification, often after some degree of social and medical transition, are increasingly visible. We recruited 78 US individuals ages 18-33 years who previously identified as transgender and had stopped identifying as transgender at least six months prior. On average, participants first identified as transgender at 17.1 years of age and had done so for 5.4 years at the time of their participation. Most (83%) participants had taken several steps toward social transition and 68% had taken at least one medical step. By retrospective reports, fewer than 17% of participants met DSM-5 diagnostic criteria for Gender Dysphoria in Childhood. In contrast, 53% of participants believed that "rapid-onset gender dysphoria" applied to them. Participants reported a high rate of psychiatric diagnoses, with many of these prior to trans-identification. Most participants (N = 71, 91%) were natal females. Females (43%) were more likely than males (0%) to be exclusively homosexual. Participants reported that their psychological health had improved dramatically since detransition/desistance, with marked decreases in self-harm and gender dysphoria and marked increases in flourishing. The most common reason given for initial trans-identification was confusing mental health issues or reactions to trauma for gender dysphoria. Reasons for detransition were more likely to reflect internal changes (e.g., the participants' own thought processes) than external pressures (e.g., pressure from family). Results suggest that, for some transgender individuals, detransition is both possible and beneficial.

Prosocial motives underlie scientific censorship by scientists: A perspective and research agenda

Science is among humanity's greatest achievements, yet scientific censorship is rarely studied empirically. We explore the social, psychological, and institutional causes and consequences of scientific censorship (defined as actions aimed at obstructing particular scientific ideas from reaching an audience for reasons other than low scientific quality). Popular narratives suggest that scientific censorship is driven by authoritarian officials with dark motives, such as dogmatism and intolerance. Our analysis suggests that scientific censorship is often driven by scientists, who are primarily motivated by self-protection, benevolence toward peer scholars, and prosocial concerns for the well-being of human social groups. This perspective helps explain both recent findings on scientific censorship and recent changes to scientific institutions, such as the use of harm-based criteria to evaluate research. We discuss unknowns surrounding the consequences of censorship and provide recommendations for improving transparency and accountability in scientific decision-making to enable the exploration of these unknowns. The benefits of censorship may sometimes outweigh costs. However, until costs and benefits are examined empirically, scholars on opposing sides of ongoing debates are left to quarrel based on competing values, assumptions, and intuitions.

Sexual Orientation, Sexual Motivation, and Erotic Target Identity Inversions in Male Adult Baby/Diaper Lovers

Adult baby/diaper lovers (AB/DLs) enjoy role-playing as babies and/or wearing diapers. They also engage in other related activities, such as urinating or defecating themselves and having an adult care for them. Previous surveys have revealed that AB/DLs commonly report sexual motivation, a finding that is corroborated by case reports in the psychiatric literature and some media interviews. The fact that AB/DLs change their appearance and behavior to become more like babies raises the possibility that they have an erotic target identity inversion (ETII). In ETIIs, a person's external erotic target is inverted into the self, resulting in sexual arousal by the fantasy of being a member of the target class or by imitating one. If AB/DLs are sexually motivated by an ETII, they should experience both sexual attraction to babies and sexual arousal by the fantasy of being a baby. We surveyed 207 male AB/DLs recruited from the Internet about their sexual orientation, sexual motivation, and sexual interests for a primarily quantitative analysis. Consistent with past research, a substantial minority of participants reported non-heterosexual identities (42%), and a large majority reported some degree of sexual motivation for being AB/DLs (93%). Wearing diapers and urinating or defecating oneself were rated as especially sexual. Even though 40% of participants reported sexual arousal by the fantasy of being a baby, only 4% reported sexual attraction to babies. This pattern of results is contrary to predictions from the concept of ETIIs. Instead, participants indicated that physical or mental pain, humiliation, and an adult woman were important to their sexual fantasies of being a baby. Masochism appears to be a promising alternative to an ETII for explaining the sexual motivation of AB/DLs.

Elaborating and Testing Erotic Target Identity Inversion Theory in Three Paraphilic Samples

Some men sexually attracted to types of persons (e.g., women) or things (e.g., animals) also have internalized sexual attractions: sexual arousal by the idea of being the type of person or thing to whom they are attracted. Consequently, some of these men develop erotic target identity inversions, in which they imitate, yearn to be, or identify as an instance of their erotic target. Erotic Target Identity Inversion Theory predicts that for every external erotic target to which men are attracted, a subset of men will develop an internalized sexual attraction, which may cause an erotic target identity inversion. We examined these predictions in Internet surveys of three samples of men with paraphilic sexual interests: 322 men attracted to amputees, 1501 men attracted to animals, and 402 men attracted to severely obese persons. All samples included substantial minorities of men reporting internalized sexual attractions and erotic target identity inversions specific to their external sexual attractions (e.g., men attracted to amputees who are also aroused by the fantasy of being amputees and wish to become amputees). The correlation between degree of each internalized sexual attraction and degree of its corresponding erotic target identity inversion was approximately 1.0 after correction for attenuation. In each sample, participants' specific internalized sexual attraction was positively correlated with autogynephilia, likely the most common internalized sexual attraction in men. Erotic Target Identity Inversion Theory can potentially explain a variety of otherwise puzzling phenomena, including transgender identity among female-attracted natal males and men seeking amputations of healthy limbs.

Rapid Onset Gender Dysphoria: Parent Reports on 1655 Possible Cases

During the past decade there has been a dramatic increase in adolescents and young adults (AYA) complaining of gender dysphoria. One influential if controversial explanation is that the increase reflects a socially contagious syndrome: Rapid Onset Gender Dysphoria (ROGD). We report results from a survey of parents who contacted the website ParentsofROGDKids.com because they believed their AYA children had ROGD. Results focused on 1655 AYA children whose gender dysphoria reportedly began between ages 11 and 21 years, inclusive. These youths were disproportionately (75%) natal female. Natal males had later onset (by 1.9 years) than females, and they were much less likely to have taken steps toward social gender transition (65.7% for females versus 28.6% for males). Pre-existing mental health issues were common, and youths with these issues were more likely than those without them to have socially and medically transitioned. Parents reported that they had often felt pressured by clinicians to affirm their AYA child's new gender and support their transition. According to the parents, AYA children's mental health deteriorated considerably after social transition. We discuss potential biases of survey responses from this sample and conclude that there is presently no reason to believe that reports of parents who support gender transition are more accurate than those who oppose transition. To resolve controversies regarding ROGD, it is desirable that future research includes data provided by both pro- and anti-transition parents, as well as their gender dysphoric AYA children.

How Autogynephilic Are Natal Females?

Blanchard proposed that autogynephilia is a natal male's paraphilic sexual arousal in response to the thought or fantasy of being a woman. Furthermore, based on evidence collected from natal males with gender dysphoria, Blanchard argued that autogynephilia is the fundamental motivation among nonhomosexual males (i.e., those not exclusively attracted to men) who pursue sex reassignment surgery or live as transgender women. These ideas have been challenged by several writers who have asserted, or offered evidence, that autogynephilia is common among women. However, their evidence was weakened by problematic measures and limited comparison groups. We compared four samples of autogynephilic natal males (N = 1549), four samples of non-autogynephilic natal males (N = 1339), and two samples of natal females (N = 500), using Blanchard's original measure: the Core Autogynephilia Scale. The autogynephilic samples had much higher mean scores compared with non-autogynephilic natal males and natal females, who were similar. Our findings refute the contention that autogynephilia is common among natal females.

Low Perinatal Androgens Predict Recalled Childhood Gender Nonconformity in Men

The contributions of gonadal hormones to the development of human behavioral sex differences are subjects of intense scientific and social interest. Isolated gonadotropin-releasing-hormone deficiency (IGD) is a rare endocrine disorder that can reveal a possible role of early gonadal hormones. IGD is characterized by low or absent gonadal hormone production after the first trimester of gestation, but external genitalia and hence gender of rearing are concordant with chromosomal and gonadal sex. We investigated recalled childhood gender nonconformity in men (n = 65) and women (n = 32) with IGD and typically developing men (n = 463) and women (n = 1,207). Men with IGD showed elevated childhood gender nonconformity, particularly if they also reported undescended testes at birth, a marker of low perinatal androgens. Women with IGD did not differ from typically developing women. These results indicate that early androgen exposure after the first trimester contributes to male-typical gender-role behaviors in childhood.

Genome-Wide Linkage and Association Study of Childhood Gender Nonconformity in Males

Male sexual orientation is influenced by environmental and complex genetic factors. Childhood gender nonconformity (CGN) is one of the strongest correlates of homosexuality with substantial familiality. We studied brothers in families with two or more homosexual brothers (409 concordant sibling pairs in 384 families, as well as their heterosexual brothers), who self-recalled their CGN. To map loci for CGN, we conducted a genome-wide linkage scan (GWLS) using SNP genotypes. The strongest linkage peaks, each with significant or suggestive two-point LOD scores and multipoint LOD score support, were on chromosomes 5q31 (maximum two-point LOD = 4.45), 6q12 (maximum two-point LOD = 3.64), 7q33 (maximum two-point LOD = 3.09), and 8q24 (maximum two-point LOD = 3.67), with the latter not overlapping with previously reported strongest linkage region for male sexual orientation on pericentromeric chromosome 8. Family-based association analyses were used to identify associated variants in the linkage regions, with a cluster of SNPs (minimum association p = 1.3 × 10^-8) found at the 5q31 linkage peak. Genome-wide, clusters of multiple SNPs in the 10^-6 to 10^-8 p-value range were found at chromosomes 5p13, 5q31, 7q32, 8p22, and 10q23, highlighting glutamate-related genes. This is the first reported GWLS and genome-wide association study on CGN. Further increasing genetic knowledge about CGN and its relationships to male sexual orientation should help advance our understanding of the biology of these associated traits.

A map of desire: multidimensional scaling of men's sexual interest in male and female children and adults

BACKGROUND

Men sexually interested in children of a specific combination of maturity and sex tend to show some lesser interest in other categories of persons. Patterns of men's sexual interest across erotic targets' categories of maturity and sex have both clinical and basic scientific implications.

METHOD

We examined the structure of men's sexual interest in adult, pubescent, and prepubescent males and females using multidimensional scaling (MDS) across four datasets, using three large samples and three indicators of sexual interest: phallometric response to erotic stimuli, sexual offense history, and self-reported sexual attraction. The samples were highly enriched for men sexually interested in children and men accused of sexual offenses.

RESULTS

Results supported a two-dimensional MDS solution, with one dimension representing erotic targets' biological sex and the other dimension representing their sexual maturity. The dimension of sexual maturity placed adults and prepubescent children on opposite ends, and pubescent children intermediate. Differences between men's sexual interest in adults and prepubescent children of the same sex were similar in magnitude to the differences between their sexual interest in adult men and women. Sexual interest in adult men was no more associated with sexual interest in boys than sexual interest in adult women was associated with sexual interest in girls.

CONCLUSIONS

Erotic targets' sexual maturity and biological sex play important roles in men's preferences, which are predictive of sexual offending. The magnitude of men's preferences for prepubescent children v. adults of their preferred sex is large.

Evidence that perinatal ovarian hormones promote women's sexual attraction to men

Ovarian estrogens may influence the development of the human brain and behavior, but there are few opportunities to test this possibility. Isolated GnRH deficiency (IGD) is a rare endocrine disorder that could provide evidence for the role of estrogens in organizing sexually differentiated phenotypes: Unlike typical development, development in individuals with IGD is characterized by low or absent gonadal hormone production after the first trimester of gestation. Because external genitalia develop in the first trimester, external appearance is nevertheless concordant with gonadal sex in people with IGD. We therefore investigated the effects of gonadal hormones on sexual orientation by comparing participants with IGD (n = 97) to controls (n = 1670). Women with IGD reported lower male-attraction compared with typically developing women. In contrast, no consistent sexuality differences between IGD and typically developing men were evident. Ovarian hormones after the first trimester appear to influence female-typical dimensions of sexual orientation.

Familiality of Gender Nonconformity Among Homosexual Men

We examined whether recalled childhood gender nonconformity and self-reported adult gender nonconformity is familial, using data from 1154 families selected for having at least two homosexual brothers. Specifically, we examined the extent to which homosexual men's variation in gender nonconformity runs in families by examining pairs of genetic brothers who were both homosexual (N = 672-697 full sibling concordant pairs). We also examined similarity between homosexual and heterosexual brothers (N = 79-82 full sibling discordant pairs). Consistent with past studies, concordant pairs yielded modest positive correlations consistent with moderate genetic and/or familial environmental effects on gender nonconformity. Unlike results of smaller past studies, discordant pairs also yielded modest positive, though nonsignificant, correlations. Our results support the feasibility of supplementing genetic studies of male sexual orientation with analyses of gender nonconformity variation.

Sexual Arousal Patterns of Mostly Heterosexual Men

Mostly heterosexual men describe themselves as slightly bisexual, with predominant sexual attraction to women but occasional attraction to men. After "completely heterosexual," "mostly heterosexual" is the most common male sexual orientation, by self-report. However, self-reported bisexual feelings among men can diverge from patterns of genital arousal, an objective measure of sexual interest with high validity. We compared 49 mostly heterosexual and 50 completely heterosexual men's patterns of genital and subjective sexual arousal to male and female erotic stimuli. In addition, we compared these groups on relevant self-report measures pertaining to sexual feelings, identity, and behavior. Results supported increased bisexual arousal with respect to self-report and genital arousal pattern among the mostly heterosexual men, compared with the completely heterosexual men. Furthermore, mostly heterosexual men reported more childhood gender nonconformity, greater male sex partners, and less self-reported disgust or aversion to sex acts with men. "Mostly heterosexual" appears to be a gradation of male sexual orientation associated with unique genital arousal patterns, among other correlates.

Gender Nonconformity of Bisexual Men and Women

The degree to which bisexual-identified individuals are distinct from either heterosexual or homosexual individuals in their sexual orientation is an ongoing debate. We examined potential differences between these groups with respect to a strong correlate of sexual orientation, gender nonconformity (femininity in males, masculinity in females). Across pooled data, we compared self-reports of childhood gender nonconformity (n = 919) and adulthood gender nonconformity (n = 1265) and observer ratings of adulthood gender nonconformity (n = 915) between sexual orientations. Most analyses suggested a steady increase in gender nonconformity from exclusively heterosexual to exclusively homosexual. However, in some analyses, bisexual men were closer to homosexual men than to heterosexual men in their gender nonconformity. The intermediate status of bisexual people in gender nonconformity was not due to the sample having a mixture of very gender-conforming and very gender-nonconforming individuals. In total, men and women with bisexual orientations appeared neither like heterosexual nor homosexual individuals, at least with respect to their gender-related traits.

Robust evidence for bisexual orientation among men

The question whether some men have a bisexual orientation-that is, whether they are substantially sexually aroused and attracted to both sexes-has remained controversial among both scientists and laypersons. Skeptics believe that male sexual orientation can only be homosexual or heterosexual, and that bisexual identification reflects nonsexual concerns, such as a desire to deemphasize homosexuality. Although most bisexual-identified men report that they are attracted to both men and women, self-report data cannot refute these claims. Patterns of physiological (genital) arousal to male and female erotic stimuli can provide compelling evidence for male sexual orientation. (In contrast, most women provide similar physiological responses to male and female stimuli.) We investigated whether men who self-report bisexual feelings tend to produce bisexual arousal patterns. Prior studies of this issue have been small, used potentially invalid statistical tests, and produced inconsistent findings. We combined nearly all previously published data (from eight previous studies in the United States, United Kingdom, and Canada), yielding a sample of 474 to 588 men (depending on analysis). All participants were cisgender males. Highly robust results showed that bisexual-identified men's genital and subjective arousal patterns were more bisexual than were those who identified as exclusively heterosexual or homosexual. These findings support the view that male sexual orientation contains a range, from heterosexuality, to bisexuality, to homosexuality.

Neural Responses to Sexual Stimuli in Heterosexual and Homosexual Men and Women: Men's Responses Are More Specific

Patterns of genital arousal in response to gendered sexual stimuli (i.e., sexual stimuli presenting members of only one sex at a time) are more predictive of men's than of women's sexual orientations. Additional lines of evidence may shed light on the nature of these differences. We measured neural activation in homosexual and heterosexual men and women using fMRI while they viewed three kinds of gendered sexual stimuli: pictures of nude individuals, pictures of same-sex couples interacting, and videos of individuals self-stimulating. The primary neural region of interest was the ventral striatum (VS), an area of central importance for reward processing. For all three kinds of stimuli and for both VS activation and self-report, men's responses were more closely related to their sexual orientations compared with women's. Furthermore, men showed a much greater tendency to respond more positively to stimuli featuring one sex than to stimuli featuring the other sex, leading to higher correlations among men's responses as well as higher correlations between men's responses and their sexual orientations. Whole-brain analyses identified several other regions showing a similar pattern to the VS, and none showed an opposite pattern. Because fMRI is measured identically in men and women, our results provide the most direct evidence to date that men's sexual arousal patterns are more gender specific than women's.

The "Furry" Phenomenon: Characterizing Sexual Orientation, Sexual Motivation, and Erotic Target Identity Inversions in Male Furries

Furries are individuals who are especially interested in anthropomorphic or cartoon animals (e.g., Bugs Bunny). They often strongly identify with anthropomorphic animals and create fursonas, identities of themselves as those anthropomorphic animals. Some practice fursuiting, or wearing costumes that resemble anthropomorphic animals. Furries have been portrayed as sexually motivated in the media and popular culture, although little empirical research has addressed this issue. If some furries are sexually motivated, they may be motivated by an erotic target identity inversion (ETII): sexual arousal by the fantasy of being the same kinds of individuals to whom they are sexually attracted. Furries with ETIIs would experience both sexual attraction to anthropomorphic animals and sexual arousal by fantasizing about being anthropomorphic animals, because they often change their appearance and behavior to become more like anthropomorphic animals. We surveyed 334 male furries recruited from the Internet about their sexual orientation, sexual motivation, and sexual interests. A large majority of our sample reported non-heterosexual identities (84%) and some degree of sexual motivation for being furries (99%). Male furries also tended to report a pattern of sexual interests consistent with an ETII involving anthropomorphic animals. Both sexual attraction to anthropomorphic animals and sexual arousal by fantasizing about being anthropomorphic animals were nearly universal. Furthermore, male furries tended to be sexually aroused by fantasizing about being the same kinds of anthropomorphic animals to whom they were sexually attracted, with respect to gender and species. This sexual motivation and these unusual sexual interests do not justify discrimination or stigmatization.

Visual Attention to Sexual Stimuli in Mostly Heterosexuals

Individuals who report mostly heterosexual orientations (i.e., mostly sexually attracted to the opposite sex, but occasionally attracted to the same sex) outnumber all other non-heterosexual individuals combined. The present study examined whether mostly heterosexual men and women view same- and other-sex sexual stimuli differently than exclusively heterosexual men and women. A novel eye-tracking paradigm was used with 162 mostly and exclusively heterosexual men and women. Compared to exclusively heterosexual men, mostly heterosexual men demonstrated greater attention to sexually explicit features (i.e., genital regions and genital contact regions) of solo male and male-male erotic stimuli, while demonstrating equivalent attention to sexually explicit features of solo female and female-female erotic stimuli. Mediation analyses suggested that differences between mostly and exclusively heterosexual profiles in men could be explained by mostly heterosexual men's increased sexual attraction to solo male erotica, and their increased sexual attraction and reduced disgust to the male-male erotica. No comparable differences in attention were observed between mostly and exclusively heterosexual women-although mostly heterosexual women did demonstrate greater fixation on visual erotica overall-a pattern of response that was found to be mediated by reduced disgust.

Neural Correlates of Sexual Orientation in Heterosexual, Bisexual, and Homosexual Women

We used fMRI to investigate neural correlates of responses to erotic pictures and videos in heterosexual (N = 26), bisexual (N = 26), and homosexual (N = 24) women, ages 25–50. We focused on the ventral striatum, an area of the brain associated with desire, extending previous findings from the sexual psychophysiology literature in which homosexual women had greater category specificity (relative to heterosexual and bisexual women) in their responses to male and female erotic stimuli. We found that homosexual women’s subjective and neural responses reflected greater bias towards female stimuli, compared with bisexual and heterosexual women, whose responses did not significantly differ. These patterns were also suggested by whole brain analyses, with homosexual women showing category-specific activations of greater extents in visual and auditory processing areas. Bisexual women tended to show more mixed patterns, with activations more responsive to female stimuli in sensory processing areas, and activations more responsive to male stimuli in areas associated with social cognition.

Genome-Wide Association Study of Male Sexual Orientation

Family and twin studies suggest that genes play a role in male sexual orientation. We conducted a genome-wide association study (GWAS) of male sexual orientation on a primarily European ancestry sample of 1,077 homosexual men and 1,231 heterosexual men using Affymetrix single nucleotide polymorphism (SNP) arrays. We identified several SNPs with p < 10-5, including regions of multiple supporting SNPs on chromosomes 13 (minimum p = 7.5 × 10-7) and 14 (p = 4.7 × 10-7). The genes nearest to these peaks have functions plausibly relevant to the development of sexual orientation. On chromosome 13, SLITRK6 is a neurodevelopmental gene mostly expressed in the diencephalon, which contains a region previously reported as differing in size in men by sexual orientation. On chromosome 14, TSHR genetic variants in intron 1 could conceivably help explain past findings relating familial atypical thyroid function and male homosexuality. Furthermore, skewed X chromosome inactivation has been found in the thyroid condition, Graves' disease, as well as in mothers of homosexual men. On pericentromeric chromosome 8 within our previously reported linkage peak, we found support (p = 4.1 × 10-3) for a SNP association previously reported (rs77013977, p = 7.1 × 10-8), with the combined analysis yielding p = 6.7 × 10-9, i.e., a genome-wide significant association.

Neural Correlates of Sexual Orientation in Heterosexual, Bisexual, and Homosexual Men

Studies of subjective and genital sexual arousal in monosexual (i.e. heterosexual and homosexual) men have repeatedly found that erotic stimuli depicting men’s preferred sex produce strong responses, whereas erotic stimuli depicting the other sex produce much weaker responses. Inconsistent results have previously been obtained in bisexual men, who have sometimes demonstrated distinctly bisexual responses, but other times demonstrated patterns more similar to those observed in monosexual men. We used fMRI to investigate neural correlates of responses to erotic pictures and videos in heterosexual, bisexual, and homosexual men, ages 25–50. Sixty participants were included in video analyses, and 62 were included in picture analyses. We focused on the ventral striatum (VS), due to its association with incentive motivation. Patterns were consistent with sexual orientation, with heterosexual and homosexual men showing female-favoring and male-favoring responses, respectively. Bisexual men tended to show less differentiation between male and female stimuli. Consistent patterns were observed in the whole brain, including the VS, and also in additional regions such as occipitotemporal, anterior cingulate, and orbitofrontal cortices. This study extends previous findings of gender-specific neural responses in monosexual men, and provides initial evidence for distinct brain activity patterns in bisexual men.

Bisexual Phenomena Among Gay-Identified Men

A high proportion of self-identified gay men exhibit aspects of bisexuality during their lives. Some identify as bisexual before later identifying as gay; this has been called transitional bisexuality. Although many gay men report no attraction to women-or even sexual disgust toward them-others report some slight attraction to women. The latter have been studied as mostly homosexual men. We studied men with and without a history of transitional bisexuality, as well as mostly homosexual (i.e., those with Kinsey scores of 5) and completely homosexual (i.e., those with Kinsey scores of 6) men with respect to their sexual history with women, their current self-reported sexual arousal and disgust toward women and men, and their patterns of genital sexual arousal to female and male stimuli. Gay men with a history of transitional bisexuality generally lacked current sexual attraction and sexual arousal to women, compared with other gay men. Thus, transitional bisexuality among future gay men is mostly a matter of transitional bisexual identification. In contrast, mostly homosexual men showed statistically significant increases in genital arousal to female stimuli, compared with completely homosexual men.

Sexual Arousal Patterns of Autogynephilic Male Cross-Dressers

Men's sexual arousal patterns have been an important window into the nature of their erotic interests. Autogynephilia is a natal male's paraphilic tendency to be sexually aroused by the thought or image of being a woman. Autogynephilic arousal per se is difficult to assess objectively, because it is inwardly focused. However, assessing sexual arousal patterns of autogynephilic males in response to external stimuli is also potentially useful. For example, there is substantial association between autogynephilia and gynandromorphophilia (GAMP), or sexual attraction to gynandromorphs (GAMs), colloquially "she-males." GAMP men's sexual arousal patterns in response to GAM, female, and male stimuli have recently been characterized. In the present study, we extended this understanding by comparing the sexual arousal patterns of autogynephilic male cross-dressers, GAMP men, heterosexual men, and homosexual men. Erotic stimuli included sexually explicit videos of men, women, and GAMs. Autogynephilic men were much more similar in their arousal patterns to heterosexual and GAMP men than to homosexual men. However, similar to GAMP men, autogynephilic men showed increased arousal by GAM stimuli relative to female stimuli compared with heterosexual men.

Who Are Gynandromorphophilic Men? An Internet Survey of Men with Sexual Interest in Transgender Women

Gynandromorphophilia (GAMP) is attraction to gynandromorphs (GAMs), who are natal males with both breasts and a penis, colloquially known as "she-males." Men with GAMP (n = 314) and heterosexual men not attracted to GAMs (n = 211) completed an Internet survey regarding their sexual attraction patterns, relationship history, and potential correlates of GAMP. Men with GAMP reported much higher attraction to natal women than to men, although they also reported slightly higher levels of bisexual feelings compared with controls. Men with GAMP were equally attracted to natal women and GAMs, on average. Thus, GAMP is best considered an unusual form of heterosexuality rather than a separate sexual orientation. Indeed, men with GAMP scored much higher than controls on a measure of autogynephilia, or sexual arousal by the idea or fantasy of being a woman, which is also considered a variant of heterosexual attraction.

Autopedophilia

The most salient dimension of men’s sexual orientation is gender: attraction to males versus females. A second dimension is sexual maturity: attraction to children versus adults. A less appreciated dimension is location: attraction to other individuals versus the sexual fantasy of being one of those individuals. Men sexually aroused by the idea or fantasy of being the kinds of individuals to whom they are sexually attracted have an erotic-target identity inversion (ETII). We conducted an online survey to investigate the prevalence and phenomenology of ETIIs among 475 men sexually attracted to children. Autopedophilia, or sexual arousal by the idea of being a child, was common. Furthermore, autopedophilic men tended to be sexually aroused by imagining themselves as the kinds of children (with respect to gender and age) to whom they are sexually attracted. Results support the concept of ETIIs and exemplify the simultaneous importance of three dimensions of male sexual orientation.

Sexual Orientation, Controversy, and Science

Summary

Ongoing political controversies around the world exemplify a long-standing and widespread preoccupation with the acceptability of homosexuality. Nonheterosexual people have seen dramatic surges both in their rights and in positive public opinion in many Western countries. In contrast, in much of Africa, the Middle East, the Caribbean, Oceania, and parts of Asia, homosexual behavior remains illegal and severely punishable, with some countries retaining the death penalty for it. Political controversies about sexual orientation have often overlapped with scientific controversies. That is, participants on both sides of the sociopolitical debates have tended to believe that scientific findings—and scientific truths—about sexual orientation matter a great deal in making political decisions. The most contentious scientific issues have concerned the causes of sexual orientation—that is, why are some people heterosexual, others bisexual, and others homosexual? The actual relevance of these issues to social, political, and ethical decisions is often poorly justified, however.

Who are gynandromorphophilic men? Characterizing men with sexual interest in transgender women

BACKGROUND

Gynandromorphophilia (GAMP) is sexual interest in gynandromorphs (GAMs; colloquially, shemales). GAMs possess a combination of male and female physical characteristics. Thus, GAMP presents a challenge to conventional understandings of sexual orientation as sexual attraction to the male v. female form. Speculation about GAMP men has included the ideas that they are homosexual, heterosexual, or especially, bisexual.

METHOD

We compared genital and subjective sexual arousal patterns of GAMP men with those of heterosexual and homosexual men. We also compared these groups on their self-ratings of sexual orientation and sexual interests.

RESULTS

GAMP men had arousal patterns similar to those of heterosexual men and different from those of homosexual men. However, compared to heterosexual men, GAMP men were relatively more aroused by GAM erotic stimuli than by female erotic stimuli. GAMP men also scored higher than both heterosexual and homosexual men on a measure of autogynephilia.

CONCLUSIONS

Results provide clear evidence that GAMP men are not homosexual. They also indicate that GAMP men are especially likely to eroticize the idea of being a woman.

Developmental exposure to a complex PAH mixture causes persistent behavioral effects in naive Fundulus heteroclitus (killifish) but not in a population of PAH-adapted killifish

Acute exposures to some individual polycyclic aromatic hydrocarbons (PAHs) and complex PAH mixtures are known to cause cardiac malformations and edema in the developing fish embryo. However, the heart is not the only organ impacted by developmental PAH exposure. The developing brain is also affected, resulting in lasting behavioral dysfunction. While acute exposures to some PAHs are teratogenically lethal in fish, little is known about the later life consequences of early life, lower dose subteratogenic PAH exposures. We sought to determine and characterize the long-term behavioral consequences of subteratogenic developmental PAH mixture exposure in both naive killifish and PAH-adapted killifish using sediment pore water derived from the Atlantic Wood Industries Superfund Site. Killifish offspring were embryonically treated with two low-level PAH mixture dilutions of Elizabeth River sediment extract (ERSE) (TPAH 5.04 μg/L and 50.4 μg/L) at 24h post fertilization. Following exposure, killifish were raised to larval, juvenile, and adult life stages and subjected to a series of behavioral tests including: a locomotor activity test (4 days post-hatch), a sensorimotor response tap/habituation test (3 months post hatch), and a novel tank diving and exploration test (3months post hatch). Killifish were also monitored for survival at 1, 2, and 5 months over 5-month rearing period. Developmental PAH exposure caused short-term as well as persistent behavioral impairments in naive killifish. In contrast, the PAH-adapted killifish did not show behavioral alterations following PAH exposure. PAH mixture exposure caused increased mortality in reference killifish over time; yet, the PAH-adapted killifish, while demonstrating long-term rearing mortality, had no significant changes in mortality associated with ERSE exposure. This study demonstrated that early embryonic exposure to PAH-contaminated sediment pore water caused long-term locomotor and behavioral alterations in killifish, and that locomotor alterations could be observed in early larval stages. Additionally, our study highlights the resistance to behavioral alterations caused by low-level PAH mixture exposure in the adapted killifish population. Furthermore, this is the first longitudinal behavioral study to use killifish, an environmentally important estuarine teleost fish, and this testing framework can be used for future contaminant assessment.

p53 mutations cooperate with oncogenic Kras to promote adenocarcinoma from pancreatic ductal cells

Pancreatic cancer is one of the most lethal malignancies, with virtually all patients eventually succumbing to their disease. Mutations in p53 have been documented in >50% of pancreatic cancers. Owing to the high incidence of p53 mutations in PanIN 3 lesions and pancreatic tumors, we interrogated the comparative ability of adult pancreatic acinar and ductal cells to respond to oncogenic Kras and mutant Tp53(R172H) using Hnf1b:CreER(T2) and Mist1:CreER(T2) mice. These studies involved co-activation of a membrane-tethered GFP lineage label, allowing for direct visualization and isolation of cells undergoing Kras and mutant p53 activation. Kras activation in Mist1(+) adult acinar cells resulted in brisk PanIN formation, whereas no evidence of pancreatic neoplasia was observed for up to 6 months following Kras activation in Hnf1beta(+) adult ductal cells. In contrast to the lack of response to oncogenic Kras alone, simultaneous activation of Kras and mutant p53 in adult ductal epithelium generated invasive PDAC in 75% of mice as early as 2.5 months after tamoxifen administration. These data demonstrate that pancreatic ductal cells, whereas exhibiting relative resistance to oncogenic Kras alone, can serve as an effective cell of origin for pancreatic ductal adenocarcinoma in the setting of gain-of-function mutations in p53.

Neurotoxicity of FireMaster 550® in zebrafish (Danio rerio): Chronic developmental and acute adolescent exposures

BACKGROUND

FireMaster® 550 (FM 550) is the second most commonly used flame retardant (FR) product in consumer goods and has been detected in household dust samples. However, neurobehavioral effects associated with exposure have not been characterized in detail. We investigated the behavioral effects of FM 550 in zebrafish to facilitate the integration of the cellular and molecular effects of FM 550 with its behavioral consequences. The effects of developmental FM 550 exposure on zebrafish larvae swimming shortly after the end of exposure as well as the persisting effects of this exposure on adolescent behavior were studied. In addition, the acute effects of FM 550 on behavior with exposure during adolescence in zebrafish were studied.

METHODS

Developmental exposure to 0, 0.01, 0.1 or 1 mg/L of FM 550 via immersion spanned 0-5 days post fertilization, with larval testing on day 6 and adolescent testing on days 40-45. Acute adolescent (45 dpf) exposure was to 0, 1.0 or 3.0 mg/L of FM 550 via immersion, for 24 h, with testing 2 h or 1 week later. The vehicle condition was colony tank water with .0004% (developmental) or .0012% (adolescent) DMSO. Zebrafish behavior was characterized across several domains including learning, social affiliation, sensorimotor function, predator escape, and novel environment exploration.

RESULTS

Persisting effects of developmental FM 550 exposure included a significant (p<0.01) reduction in social behavior among all dose groups. Acute FM 550 exposure during adolescence caused hypoactivity and reduced social behavior (p's<0.05) when the fish were tested 2 h after exposure. These effects were attenuated at the 1 week post exposure testing point

DISCUSSION

Taken together, these data indicate that FM 550 may cause persisting neurobehavioral alterations to social behavior in the absence of perturbations along other behavioral domains and that developmental exposure is more costly to the organism than acute adolescent exposure.

The Psychometric Structure of Items Assessing Autogynephilia

Autogynephilia, or paraphilic sexual arousal in a man to the thought or image of himself as a woman, manifests in a variety of different behaviors and fantasies. We examined the psychometric structure of 22 items assessing five known types of autogynephilia by subjecting them to exploratory factor analysis in a sample of 149 autogynephilic men. Results of oblique factor analyses supported the ability to distinguish five group factors with suitable items. Results of hierarchical factor analyses suggest that the five group factors were strongly underlain by a general factor of autogynephilia. Because the general factor accounted for a much greater amount of the total variance of the 22 items than did the group factors, the types of autogynephilia that a man has seem less important than the degree to which he has autogynephilia. However, the five types of autogynephilia remain conceptually useful because meaningful distinctions were found among them, including differential rates of endorsement and differential ability to predict other relevant variables like gender dysphoria. Factor-derived scales and subscales demonstrated good internal consistency reliabilities, and validity, with large differences found between autogynephilic men and heterosexual male controls. Future research should attempt to replicate our findings, which were mostly exploratory.

Genome-wide scan demonstrates significant linkage for male sexual orientation

BACKGROUND

Findings from family and twin studies support a genetic contribution to the development of sexual orientation in men. However, previous studies have yielded conflicting evidence for linkage to chromosome Xq28.

METHOD

We conducted a genome-wide linkage scan on 409 independent pairs of homosexual brothers (908 analyzed individuals in 384 families), by far the largest study of its kind to date.

RESULTS

We identified two regions of linkage: the pericentromeric region on chromosome 8 (maximum two-point LOD = 4.08, maximum multipoint LOD = 2.59), which overlaps with the second strongest region from a previous separate linkage scan of 155 brother pairs; and Xq28 (maximum two-point LOD = 2.99, maximum multipoint LOD = 2.76), which was also implicated in prior research.

CONCLUSIONS

Results, especially in the context of past studies, support the existence of genes on pericentromeric chromosome 8 and chromosome Xq28 influencing development of male sexual orientation.

Long-term behavioral impairment following acute embryonic ethanol exposure in zebrafish

BACKGROUND

Developmental exposure to ethanol has long been known to cause persisting neurobehavioral impairment. However, the neural and behavioral mechanisms underlying these deficits and the importance of exposure timing are not well-characterized. Given the importance of timing and sequence in neurodevelopment it would be expected that alcohol intoxication at different developmental periods would result in distinct neurobehavioral consequences.

METHODS

Zebrafish embryos were exposed to ethanol (0%, 1%, 3%) at either 8-10 or 24-27 h post-fertilization (hpf) then reared to adolescence and evaluated on several behavioral endpoints. Habituation to a repeated environmental stimulus and overall sensorimotor function were assessed using a tap startle test; measurements of anxiety and exploration behavior were made following introduction to a novel tank; and spatial discrimination learning was assessed using aversive control in a three-chambered apparatus. Overt signs of dysmorphogenesis were also scored (i.e. craniofacial malformations, including eye diameter and midbrain-hindbrain boundary morphology).

RESULTS

Ethanol treated fish were more active both at baseline and following a tap stimulus compared to the control fish and were hyperactive when placed in a novel tank. These effects were more prominent following exposure at 24-27 hpf than with the earlier exposure window, for both dose groups. Increases in physical malformation were only present in the 3% ethanol group; all malformed fish were excluded from behavioral testing.

DISCUSSION

These results suggest specific domains of behavior are affected following ethanol exposure, with some but not all of the tests revealing significant impairment. The behavioral phenotypes following distinct exposure windows described here can be used to help link cellular and molecular mechanisms of developmental ethanol exposure to functional neurobehavioral effects.