BACKGROUND: The purpose of this review is to examine the notion of a behavioural phenotype for Angelman syndrome and identify methodological and conceptual influences on the accepted presentation. METHODS: Studies examining the behavioural characteristics associated with Angelman syndrome are reviewed and methodology is described. RESULTS: Potential bias in the description of the phenotype emerges with the use of case and cohort studies with the absence of comparison groups. A trend in the literature from a direct gene effect to a socially mediated effect on laughter is evident. CONCLUSION: Evidence for a behavioural phenotype of Angelman syndrome has begun to emerge. However, by adopting the concept of a 'behavioural phenotype', attention may become biased towards the underlying biological basis of the syndrome, with developmental and environmental factors being overlooked.