Reconceptualizing Testimonial Reliability in Children with Intellectual and Developmental Disabilities: A Systematic Review and Process-Oriented Framework.

Abstract

Children with intellectual and developmental disabilities (IDD) face elevated risks of victimization and may participate in forensic interviews, yet their reports are often evaluated through deficit-based assumptions. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, this review synthesized 67 studies (2000-2026; PsycINFO, PubMed, Web of Science) examining how cognitive, linguistic, adaptive, executive, and social-interactive factors, together with interview conditions, relate to testimonial performance. Findings revealed a recurring but not universal quantity-accuracy dissociation: children with IDD often provided fewer details than typically developing peers, yet their accuracy was sometimes comparable once developmental level and elicitation conditions were considered. Suggestibility varied across studies and was more pronounced under repeated, leading, or linguistically complex questioning. Fuzzy-trace theory and source monitoring theory jointly explained the preservation of core event information despite reduced detail, and source errors under demanding retrieval conditions. The resulting framework conceptualizes accuracy, completeness, consistency, and suggestibility as conditional outcomes of the fit between functional developmental profiles and interview demands, extending existing developmental and forensic interviewing models and providing a basis for developmentally calibrated assessment and practice.