Atypical Behavioral Responsiveness to Pressure in Autistic Children Across Two Independent Samples

Background: Hypo- and hyperreactivity to sensory input are included in the DSM-5 diagnostic criteria for autism spectrum disorder (ASD). While deep pressure contributes to the development of the body schema, motor organization, and affective regulation, behavioral responsiveness to sustained deep pressure has rarely been quantified directly, and most available evidence derives from caregiver-report instruments. Objective: This study aimed to compare behavioral response thresholds to deep pressure between autistic and neurotypical (NT) children, to test whether group differences were replicated across two independent samples recruited in ecologically comparable regions (southern Italy and southern Argentina), and to evaluate the feasibility of a standardized, low-cost protocol based on a pediatric aneroid sphygmomanometer. Methods: A total of 511 children aged 3–14 years participated (174 autistic and 337 NT children). ASD diagnoses were established according to DSM-5 criteria by specialized clinicians. Two independent samples of Italian and Argentine children were examined. Graduated pressure was applied using a pediatric cuff at four limb sites, and the behavioral response threshold was recorded when the child first signaled detection. Mean behavioral response thresholds were compared between the ASD and NT groups, across age groups within the ASD samples, and across language-status categories. Results: Mean composite behavioral response thresholds were higher in ASD than in NT children across all four age bands in both countries, and these differences persisted after adjustment for exact age and recorded sex. Higher thresholds in ASD were also observed at each anatomical site. Within the Italian ASD sample, verbal children had lower thresholds than minimally verbal and nonverbal children, while in the Argentine sample, only the nonverbal–verbal contrast remained statistically significant after correction. No statistically significant nonverbal–minimally verbal difference was found. Conclusions: Autistic participants showed markedly higher behavioral response thresholds than NT participants. Verbal participants in the Italian sample had lower response thresholds than minimally verbal and nonverbal children. A standardized sphygmomanometer-based protocol may offer a feasible approach for research and, pending further validation, for clinical use in low-resource settings.