The use of humour is a complex and intriguing aspect of human behaviour. Nash goes as far as to claim that ‘humour is a specifying characteristic of humanity’, comparable in this respect to ‘the power of speech, the mathematical gift, the gripping thumb’ (Nash 1985: 1). Humour is present throughout social conventions and cultural artefacts, and the use of humour is highly valued in interactions between people. Despite this apparent importance, there is, as Raskin has observed, currently no major theory of humour, in the sense of something which ‘explains what is funny, why it is funny, how it is funny, when it is funny, and to whom it is funny’ (Raskin 1998: 3, italics in original). This statement might seem to conflict with the literature on humour, where there are many proposals for dealing with humour, often claiming to be theories (e.g. Veatch (1998), Berger (1998), Latta (1999) ). However, most of these ‘theories’ rarely define their basic terms formally, and are insufficiently developed to make precise falsifiable predictions. That is, they are at best interesting informal discussions, but are not formal theories or models. Nevertheless, we shall follow common practice and continue to refer to these ideas as ‘theories’.