SEX DIFFERENCES IN AUTISM SPECTRUM DISORDER: INTERNATIONAL RESEARCH EVIDENCE AND PHENOTYPIC CHARACTERISTICS

Abstract

The article presents a systematic theoretical analysis of recent research on sex differences in the phenotype of autism spectrum disorder (ASD). The relevance of the topic is determined by the need to reconsider long-standing diagnostic approaches that were predominantly based on male samples and resulted in the establishment of a «male» normative profile of autism. The persistent underrepresentation of girls in empirical and clinical cohorts has contributed to the systematic underrecognition of the female phenotype and has led to diagnostic biases that delay timely identification. A synthesis of current empirical studies demonstrates that sex differences in ASD emerge across multiple levels of functioning, including behavioral, cognitive, adaptive, neurobiological and comorbid domains. Particular attention is given to the phenomenon of camouflaging, which is more frequently observed among girls and constitutes a key mechanism reducing the visibility of autistic traits. As a result, many girls present with hidden or atypical symptom profiles that escape detection when assessed with traditional tools.

The review also highlights the moderating role of cognitive functioning, which shapes the representation of boys and girls across different intellectual levels and contributes to the variability of observed sex ratios. Typical patterns described in the literature include more pronounced externalizing behaviors among boys and greater internalizing symptoms, such as anxiety and depression, among girls. Methodological factors influencing inconsistencies across studies are examined, including sample heterogeneity, variability of diagnostic instruments, diversity of data sources and unequal sex distribution.

The analysis emphasizes the scarcity of research addressing sex differences in ASD within the Ukrainian scientific context and underscores the importance of integrating international findings to inform evidence-based diagnostic and clinical practices. The article concludes that sex differences in ASD represent a systemic and multifaceted phenomenon that must be accounted for in assessment, research design and the development of gender-sensitive diagnostic frameworks.