The broad autism phenotype has fascinated researchers for decades. It describes a constellation of milder autistic characteristics—such as socially aloof personality, pragmatic language difficulties, and rigid, inflexible behavior—that appear at levels below the threshold for an autism diagnosis. Studies have repeatedly shown that these traits are more common among first-degree relatives of children with autism spectrum disorder than in the general population, a pattern that has helped researchers understand the hereditary architecture of autism. Because the phenotype represents an expression of the same genetic liability that, in stronger forms, produces the full condition, measuring it accurately in relatives can sharpen both genetic studies and family-centered clinical research.

The questionnaire at the heart of the new study, originally developed in English, is a 36-item self-report measure designed to capture these traits in adults. It yields a total score along with three subscale scores corresponding to its three underlying dimensions: Aloof Personality, Rigid Personality, and Pragmatic Language. Each item is rated on a six-point scale ranging from strongly disagree to strongly agree, allowing respondents to convey nuanced self-assessments. Translating such an instrument, however, is far more mechanical than swapping words between languages; it demands careful cultural adaptation so that idioms, social norms, and conceptual framings resonate with the target population while preserving the original construct.

To establish the Turkish version, the research team, led by corresponding author Mert Şenel of the Department of Psychiatry at Ankara Bilkent City Hospital, recruited a sample of 164 parents of children diagnosed with autism spectrum disorder and 81 parents of typically developing children. Every participant completed both the adapted Broad Autism Phenotype Questionnaire and the Autism Quotient, a widely used screening instrument for autistic traits in adults. In addition, the researchers evaluated test–retest reliability by asking 44 randomly selected parents of children with autism to complete the questionnaire again after an interval of three to four weeks, a standard approach for checking whether a measure produces stable results over time.

The statistical scrutiny began with confirmatory factor analysis, a technique that tests whether data collected with the translated instrument fit a predetermined structure—in this case, the original three-factor model of Aloof Personality, Rigid Personality, and Pragmatic Language. The results supported retaining the original three-factor architecture, an encouraging outcome because it means the Turkish version measures the same underlying constructs as the source instrument rather than something subtly different. That structural fidelity matters enormously when researchers want to compare findings across countries or pool data in international studies of autism genetics and family traits.

Reliability findings were largely strong. Internal consistency, assessed with Cronbach’s alpha, reached 0.840 for the total score in the self-report format and 0.831 in the informant-report format—values conventionally interpreted as good. One caveat emerged for the Rigid Personality subscale, where alphas fell to 0.610 for self-report and 0.525 for informant-report, indicating weaker internal consistency for that specific dimension. The authors report that the final construction of the questionnaire incorporated the outcomes of the confirmatory factor analysis, and the overall instrument performed reliably. Test–retest stability was assessed with the intraclass correlation coefficient, which came in at 0.815, a figure consistent with good temporal stability over the three-to-four-week retest window.

Convergent validity also received support. Scores on the Turkish Broad Autism Phenotype Questionnaire correlated significantly with scores on the Autism Quotient, meaning that parents who reported more broad-phenotype traits on one measure tended to report more autistic traits on the other. This pattern of agreement between two independently developed instruments is exactly what validity researchers hope to see, because it suggests both tools are tapping into the same psychological territory rather than measuring unrelated noise.

The discriminative results told a more nuanced story. When the researchers examined best-estimate scores—which combine self-report and informant-report information—the questionnaire distinguished significantly between parents of children with autism and parents of typically developing children, with the autism group scoring higher, precisely as the broad autism phenotype literature predicts. Interestingly, however, no significant between-group difference appeared when only self-report scores were analyzed. The authors note this contrast candidly: the combined best-estimate approach captured the group difference while self-report alone did not. This finding may reflect well-documented limitations of self-assessment for socially undesirable or subtly atypical traits, since people with aloof or rigid tendencies may not recognize or report them accurately. It also underscores the practical value of informant reports from spouses or close relatives, who may observe traits the individual himself or herself underestimates.

The research team spanned multiple institutions, including the Department of Child and Adolescent Psychiatry at Ankara Bilkent City Hospital, Gölbaşı Şehit Ahmet Özsoy State Hospital, and the Department of Speech Pathology and Audiology at the National Institute of Mental Health and Neurosciences in Bangalore, India, with Shoba S. Meera among the co-authors. The study received no external funding, was approved by the Ankara Bilkent City Hospital Ethics Committee, and was conducted in accordance with the Declaration of Helsinki, with written informed consent from all participants. The authors acknowledge the contribution of Joseph Piven, a leading figure in broad autism phenotype research, and declare no competing interests.

Why does a Turkish-language questionnaire matter beyond Türkiye? Validated instruments are the currency of cumulative science. Without them, researchers in non-English-speaking countries cannot reliably measure the phenotypes that genetic and epidemiological studies require, and cross-cultural comparisons become fraught with uncertainty about whether observed differences reflect real variation or translation artifacts. With the Broad Autism Phenotype Questionnaire now shown to be a useful instrument for assessing these traits among parents of children with autism spectrum disorder in the Turkish population, local researchers gain entry to a global research conversation. The tool can support studies of autism heritability, family counseling, screening of relatives, and investigations of how subthreshold traits relate to parenting stress, family dynamics, and developmental outcomes in siblings. At the same time, the weaker performance of the Rigid Personality subscale signals an area for continued refinement, and the advantage of best-estimate scoring offers practical guidance for future users. For a condition as genetically complex as autism, instruments like this one are quiet but essential infrastructure—unremarkable to look at, yet indispensable for translating biological insight into clinically meaningful knowledge about families living with autism.

Subject of Research: Cultural adaptation and psychometric validation of the Turkish Broad Autism Phenotype Questionnaire in parents of children with autism spectrum disorder

Article Title: Cultural adaptation and psychometric properties of the Turkish version of the broad autism phenotype questionnaire in parents of children with autism spectrum disorder

Article References: Şenel, M., Akçay, E., Büyüklüoğlu, N., Kaynak, M., Meera, S. S., Kaya, H., Çöp, E., & Göka, E. (2026). Cultural adaptation and psychometric properties of the Turkish version of the broad autism phenotype questionnaire in parents of children with autism spectrum disorder. BMC Psychology. https://doi.org/10.1186/s40359-026-05597-w

Image Credits: AI Generated

DOI: 10.1186/s40359-026-05597-w

Keywords: broad autism phenotype, autism spectrum disorder, BAPQ, psychometrics, Turkish validation, autistic traits, parents of children with autism, confirmatory factor analysis, reliability and validity, Autism Quotient, cultural adaptation, BMC Psychology