Peter Baker and David Allen describe an evidence-based approach to helping people with severe learning disabilities who behave with aggression towards themselves or others

The presentation of challenging behaviour by people with learning disabilities can be persistent and can have a huge effecton the individuals concerned and their carers. Applied behavioural analysis has offered much promise in this area, but concerns regarding the use of aversive procedures, such as punishment, along with recognition of the human rights of people with intellectual disabilities, has led to the development of positive behaviour support (PBS). This article argues that, as an emergingconcept, PBS is particularly vulnerable to corruption. To guardagainst this, PBS should always be based on data-based functional assessment and use empirically tested intervention strategies.