ABSTRACT
A crucial element in the development of the understanding of how negative thoughts operate in depression, and then in other psychological problems was the identi®cation of distorting tendencies likely to promote `cognitive errors' on the part of the sufferer. Beck (1976) distinguishes these distortions from `delusions' of more psychotic illnesses but also sees the two phenomena as being on the same continuum with the degree of distortion and error increasing the more severe the symptoms become. Beck (1963, 1976) identi®ed various types of distortion ± for example, `personalisation' and `polarised thinking', and their number was gradually expanded in succeeding publications (Beck et al., 1979b; Beck & Emery, 1985) to become a list of cognitive distortions that became standard in cognitive therapy texts thereafter, including:
· Overgeneralisation: the client typically describes a higher ratio of his experiences as negative than is really the case.
· Arbitrary inference: the client typically latches on to one particular negative view of her situation.
