Relationship Development Intervention (also known as RDI) is a parent-led approach which focuses on a child's difficulties with flexibility of thought, emotional regulation and perspective-taking.
RDI is based on the idea that children with autism have missed key developmental milestones (such as social referencing, joint attention) that enable them to think flexibly, regulate their emotions, and understand social situations.
RDI seeks to give children another chance to master these milestones in the same way that they are mastered by typically developing children: through their relationship with their parents.
An RDI consultant guides the parent to change their communication and interaction style so that they can support their child to fill in the developmental gaps they missed. This is done through everyday activities such as washing up, cooking, going for a walk, etc (some of which are video recorded and shared with the family's consultant who then provides feedback on progress).