Introduction: Attribution theory posits that helping behaviour is determined in part by the potential helper's attributions and emotions regarding the behaviour that requires help. Specifically, helping is considered to be more likely if stability is perceived as low, generating optimism for change, and if controllability is perceived as low, engendering high levels of sympathy and low levels of anger. Method: We conducted a systematic literature search to identify studies that have tested these predictions in relation to carers' propensity to help people with intellectual disabilities who display challenging behaviour. Results: The literature is inconsistent and provides at best partial support for the theory. This situation differs from that seen in the general population, where the predictions of attribution theory are broadly supported. Discussion: We consider three potential explanations for this discrepancy: the reliability of the largely vignette-based methodology, the fact that most studies fail to define "helping" explicitly and the possibility that attribution theory might apply only to low-frequency behaviours.