The current project aims to assess the feasibility of conducting Functional Communication Training in the UK with a small sample of young children (aged under 9) in an NHS setting. Three delivery formats will be assessed in order to demonstrate the feasibility of conducting FCT via different delivery methods within an NHS context. Participants will be four children aged under 9 who have an identified intellectual / developmental disability and display either self-injury, property destruction, or aggression at home. In addition, one family carer per child will be coached to implement the intervention, either following researcher intervention, or from the beginning. Data will be collected on challenging behaviour, communication responses, family carer confidence in managing behaviour, fidelity of intervention implementation, family quality of life, and acceptability of the intervention.

Inclusion Criteria:

• Child aged under 9
• Child has identified intellectual disability or genetic syndrome associated with intellectual disability (e.g. Fragile X Syndrome)
• Child uses only phrase speech (i.e. 2-3 word utterances)
• Child displays self injury, aggression, property destruction at home
• Family carers aged over 18 with capacity to consent
• Family carer speaks English as first language (to ensure that the child understands English and will therefore understand researcher)

Exclusion Criteria:

• Child experiences health condition involving pain that is not well controlled by treatment
• Child is fully deaf / blind
• Child or family carer receiving active treatment in relation to child's behaviour (e.g. direct behavioural support, parenting programme etc.)