The current state of sexual fluidity research

The standardization of a new Explicit Pornographic Picture Set (EPPS)

Pictures with affective content have been extensively used in scientific studies of emotion and sexuality. However, only a few standardized picture sets have been developed that offer explicit images, with most lacking pornographic pictures depicting diverse sexual practices. This study aimed to fill this gap through developing a standardized affective set of diverse pornographic pictures (masturbation, oral sex, vaginal sex, anal sex, group sex, paraphilia) of same-sex and opposite-sex content, offering dimensional affective ratings of valence, arousal, and dominance, as well as co-elicited discrete emotions (disgust, moral and ethical acceptance). In total, 192 pornographic pictures acquired from online pornography platforms and 24 control IAPS images have been rated by 319 participants (Mage = 22.66, SDage = 4.66) with self-reported same- and opposite-sex sexual attraction. Stimuli were representative of the entire affective space, including positively and negatively perceived pictures. Participants showed differential affective perception of pornographic pictures according to gender and sexual attraction. Differences in affective ratings related to participants' gender and sexual attraction, as well as stimuli content (depicted sexual practices and sexes). From the stimuli set, researchers can select explicit pornographic pictures based on the obtained affective ratings and technical parameters (i.e., pixel size, luminosity, color space, contrast, chromatic complexity, spatial frequency, entropy). The stimuli set may be considered a valid tool of diverse explicit pornographic pictures covering the affective space, in particular, for women and men with same- and opposite-sex sexual attraction. This new explicit pornographic picture set (EPPS) is available to the scientific community for non-commercial use.

Sexual Orientation and Gender Identity/Expression in Adolescent Research: Two Decades in Review

There is a long history of research among adolescents who are minoritized and marginalized for their sexual orientation and gender identity/expression (SOGIE). However, it remains unclear how we can best conceptualize and assess SOGIE in adolescence, resulting in different subpopulations and findings across studies. Addressing this issue, we present a narrative literature review of the conceptualization and assessment of SOGIE, and provide recommendations for conceptualizing and operationalizing these concepts. Our review indicated that most research with adolescent populations still almost exclusively assesses isolated dimensions of sexuality and gender (e.g., attraction but not identity). We argue that to make research inclusive and equitable, scholars are required to make clear substantiated decisions and be transparent about the SOGIE dimensions and, thus, subpopulations they represent.

Probing the genomic landscape of human sexuality: a critical systematic review of the literature

Whether human sexuality is the result of nature or nurture (or their complex interplay) represents a hot, often ideologically driven, and highly polarized debate with political and social ramifications, and with varying, conflicting findings reported in the literature. A number of heritability and behavioral genetics studies, including pedigree-based investigations, have hypothesized inheritance patterns of human sexual behaviors. On the other hand, in most twin, adoption, and nuclear family studies, it was not possible to disentangle between underlying genetic and shared environmental sources. Furthermore, these studies were not able to estimate the precise extent of genetic loading and to shed light both on the number and nature of the putative inherited factors, which remained largely unknown. Molecular genetic studies offer an unprecedented opportunity to overcome these drawbacks, by dissecting the molecular basis of human sexuality and allowing a better understanding of its biological roots if any. However, there exists no systematic review of the molecular genetics of human sexuality. Therefore, we undertook this critical systematic review and appraisal of the literature, with the ambitious aims of filling in these gaps of knowledge, especially from the methodological standpoint, and providing guidance to future studies. Sixteen studies were finally retained and overviewed in the present systematic review study. Seven studies were linkage studies, four studies utilized the candidate gene approach, and five studies were GWAS investigations. Limitations of these studies and implications for further research are discussed.

Fluidity in Gender Identity and Sexual Orientation Identity in Transgender and Nonbinary Youth

Changes in sexual orientation identity (SOI) and gender identity (GI) have rarely been studied in transgender and/or nonbinary youth (TNBY), but documenting such changes is important for understanding identity development and gender transition and supporting the needs of TNBY. This study examined the frequency and patterning of changes in GI and SOI across 3 months (T1-T2) and 1.5 years (T1-T4) among 183 TNBY (baseline age 14-17 years; 83.6% White, 16.9% Hispanic/Latinx) who participated in a longitudinal US study. Participants completed online surveys including measures of GI and SOI. The most common gender identity selected at T1 (with or without another gender identity) was nonbinary (56.3%), and more than half (57.4%) of youth identified with a plurisexual identity (e.g., bisexual, pansexual). GI fluidity from T1-T2 was 13.2% and from T1-T4 was 28.9%. It was equally common to move toward a nonbinary gender identity as toward a binary gender identity. SOI fluidity was more common (30.6% from T1-T2; 55.8% from T1-T4) than GI fluidity. Shifts toward plurisexual identities were more common than shifts toward monosexual identities (e.g., straight, gay). Findings highlight the need to assess changes in GI and SOI in research and clinical practice to address the unique needs of TNBY accurately and effectively.