Background. Advances in our knowledge of attachment, stress and coping may foster new explanations for the development of challenging behaviour in people with intellectual disability (ID). Method. Research on stress and coping among people with ID was reviewed initially, and then studies on the security of the attachment relationships of people with ID with their caregivers were analysed. Results. There is evidence that people with ID are more vulnerable to stress and use less effective coping strategies. Furthermore, the body of studies on attachment indicates that people with ID are at risk for developing insecure, especially disorganized attachment. There is evidence from other populations that the combination of stress, and insecure or disorganized attachment may put people at risk for developing behaviour problems. Conclusion. A stress-attachment model of the development of challenging behaviour among people with ID shows promise as an explanatory frame-work. The uncovering of these developmental mechanisms may be particularly useful for the prevention of behavioural problems.