This project addresses the added value of temperament, and its interplay with parenting, to describe and explain the large diversity in the clinical phenotype and social-emotional functioning across three prevalent neurodevelopmental disabilities (Autism, Down Syndrome, Cerebral Palsy). The meta-analysis and cross-sectional comparison will unravel syndrome-specific temperamental traits, while the longitudinal study will test the temperament-parenting interplay as transdiagnostic modifiers.