This special issue has two main purposes: (1) to contextualize autism as a multifaceted construct that can be studied across both clinical and nonclinical populations, and (2) to highlight how autism research can benefit from an interdisciplinary approach that integrates quantitative behavioural analyses, neuroimaging, and computational methods. Together, these approaches can help characterize both qualitative and quantitative differences among individuals with different constellations of autistic features.
The studies featured in the special issue approach autistic traits from different perspectives. Some focus on describing and quantifying autistic traits within specific domains, whereas others emphasize the importance of understanding autism as a multidimensional construct. Similarly, some studies examine autistic traits in large nonclinical samples with sufficient variability in trait expression, while others focus on smaller samples of individuals with a formal autism diagnosis. Taken together, these different approaches demonstrate the value of studying autistic traits across a broad range of populations and levels of trait expression.
A recurring theme across the papers is the importance of thoroughly characterizing participant samples. This includes examining how different recruitment contexts and cohorts—for example, online versus in-person participants—may differ, as well as considering other clinical symptom dimensions that may interact with or shape the presentation of autistic traits. Such considerations are critical for understanding the heterogeneity of autism and for avoiding overly narrow characterizations based on a single or highly selected population.
Another important theme is the need to study autistic traits across larger and more diverse populations of individuals both with and without formal autism diagnoses. Expanding research beyond individuals with more prototypical or clinically recognized presentations may help identify autistic trait constellations and individuals who are often overlooked. This broader approach also creates opportunities for a more transdiagnostic understanding of autistic traits—one that examines which symptom dimensions and trait features are shared across clinical conditions and diagnostic categories. Ultimately, this perspective may contribute to more multidimensional approaches to diagnosis and intervention, consistent with dimensional models of psychopathology such as the Hierarchical Taxonomy of Psychopathology (HiTOP).
The special issue includes two editorials that frame these themes from complementary perspectives. The first is a perspective that introduces the need to examine autistic traits more thoroughly across clinical and nonclinical samples and highlights computational approaches as a means of identifying both qualitative and quantitative differences in trait expression. The second is a conclusion that synthesizes the findings across the papers, identifies common themes, and offers a perspective on the next steps needed to better understand autistic traits across clinical groups. Overall, this special issue considers how research can move toward a more nuanced understanding of the qualitative and quantitative differences among individuals who meet current thresholds for an autism diagnosis, while also situating these differences within the broader dimensional landscape of autistic traits.