Posted by alexandra_k on December 20, 2004, at 1:31:28
From One to Two Factors in the Explanation of Delusion
While delusions have historically been considered paradigmatic of irrationality, the psychological theorist Brendan Maher (1999; 2003) counters that delusions are ‘not an example of disordered thinking but of normal adaptive thinking applied to explain very abnormal experiences’ (2003 p.19). He maintains that an anomalous experience of a certain intensity and duration is both necessary and sufficient for a subject to adopt a delusional belief. The nature of the anomalous experience is thought to be such that the subject is compelled to attempt to explain it. Maher considers that delusions are the inevitable result of such an attempt at explanation. He concurs with Reed’s claim that
>[G]iven the necessary information, the observer can empathize with the subject; if he himself were to have such an unusual experience he would express beliefs about it which would be just as unusual as those of the subject… They can occur in anybody who experiences disturbing phenomena, while retaining the ability to think clearly enough to be able to devise explanations of those phenomena (in Maher, 1999 p. 551).
Two-factor theorists depart from Maher by considering that delusions would not seem to be ‘normal’ or ‘rational’ responses - despite the nature of the delusional subject’s experience. Davies et al., (2002 pp. 136-137) present a battery of eight different types of delusion and they suggest that a prospective account should be assessed for adequacy with respect to how well it can explain each of these types. They argue that the anomalous experience that is relevant to each of these kinds of delusion is one that is experienced by both delusional and non-delusional subjects. They take this to be evidence that while anomalous experience may be necessary for delusion it cannot be sufficient. As such they consider that Maher’s account of the role of anomalous experience needs to be supplemented by a second factor. It is this second factor that is supposed to determine whether a subject will develop a delusion in the face of an anomalous experience. Various cognitive biases and / or deficits have been proposed as candidates for the second factor.
poster:alexandra_k
thread:431950
URL: http://www.dr-bob.org/babble/write/20041210/msgs/431950.html