齋藤 慈子

Adolescence is identified as a key period for identity development, but anthropological literature hints at cross-cultural variations. Past research suggests Japanese adolescents may experience more identity exploration/confusion compared to Western counterparts, but the reasons behind these findings remain unclear. This comparative study investigates how adolescents in England and Japan perceive and engage with their environments, and aims to identify similarities/differences that could explain cross-cultural variations in identity development. Using autophotography, 98 teenagers aged 13 to 15 years across 10 schools in England and Japan documented important aspects of their lives. We applied template analysis to qualitatively analyze these photographs/texts. Overall, we identified two shared themes between countries: “This Is Me,” reflecting personal identity through self-discovery and skill development, and “Connectedness,” emphasizing relationships and belonging. A Japan-specific theme, “Reflections Through Time,” captured the broader temporal lens of Japanese adolescents, sometimes with a sense of melancholy. This notably differed from English adolescents in our study, who focused on the present in a positive manner. These findings suggest cultural differences in how adolescents engage with their environments, which may contribute to cross-cultural variations in identity development. Our findings point to the importance of biocultural approaches in developmental research by considering the role of culture.

Introduction The extreme male brain (EMB) theory, a major causal hypothesis of autism (ASD: autism spectrum disorder), attributes excess androgens during early development as one of the causes. While studies have generally followed the EMB theory in females at birth, the co-occurrence of ASD in males at birth has been observed in conditions that are assumed to be associated with reduced androgen action during early development, including Klinefelter syndrome (KS) and sexual minorities. ASD is also associated with atypical sensory sensitivity, synesthesia, and savant syndrome. Methods In the present study, we examined adult KS individuals (n = 22), sexual minorities assigned male at birth (n = 66), and control males matched for age and educational background to those with KS [Exploratory analysis (control 1st): n = 36; Reanalysis (control 2nd): n = 583]. Participants completed a self-report questionnaire assessing sensory hypersensitivity/hyposensitivity, savant tendency (developed for the present study), synesthesia, and sexual aspects, including gender identity and sexual orientation. Results The results of the exploratory analysis suggested that individuals with KS exhibited a higher tendency toward sensory hypersensitivity/hyposensitivity than the tendency exhibited by the controls. In the Reanalysis, sexual minorities were more likely to be synesthetes, and in both analyses sexual minorities exhibited a higher savant tendency and sensory hypersensitivity/hyposensitivity than the controls. Moreover, the gender dysphoric state was associated with phenotypes observed in individuals with ASD, such as synesthesia, savant tendency, and sensory hypersensitivity/hyposensitivity. Discussion These results suggest a common physiological background among gender dysphoria, synesthesia, savant tendency, and atypical sensory sensitivity. Thus, androgynous features (reduced effects of sex steroids during early development) in males at birth may be partially related to the phenotype commonly observed in individuals with ASD. Based on the present results, we propose that the reduction of sex steroids during early development may lead to atypical neurodevelopment and be involved in the atypicality of external and internal sensory perception, and thus in the atypicality of self-concept integration, through the disruption of oxytocin and the gamma-aminobutyric acid system modulating the neural excitation/inhibition balance.

Abstract Although oxytocin (OT) plays a role in bonding between heterospecifics and conspecifics, the effects of OT on the formation of such interspecific social behavior have only been investigated between humans and dogs (Canis familiaris). In this study, for comparative evaluation of the effects of OT between dog–human and cat–human social interaction, we investigated the effects of exogenous OT on the behavior of domestic cats (Felis silvestris catus) toward humans. We intranasally administered OT or saline to 30 cats using a nebulizer and recorded their behavior (gaze, touch, vocalization, and proximity). The results showed an interaction between the administration condition and sex for gaze duration. Post hoc analyses revealed a significant increase in gaze in the OT condition in male cats but not in females. There were no significant differences in gaze toward owners and strangers in any condition or sex. The male-specific OT-mediated increase in gaze toward humans observed in this study differs from previous research on dogs wherein such effects were observed only in females. These findings suggest an overall effect of exogenous OT on cats’ social relationship with humans as well as the possibility of different mechanisms between cat–human and dog–human relationships.