Rej. Dudley et al., THE EFFECT OF SELF-REFERENT MATERIAL ON THE REASONING OF PEOPLE WITH DELUSIONS, British journal of clinical psychology, 36, 1997, pp. 575-584
People with delusions have been shown to have both generalized (Hug, G
arety & Hemsley, 1988) and content-specific biases in reasoning (Benta
ll, 1994). Our concern here was whether the hastiness that has been fo
und when people with delusions reason on relatively abstract tasks wou
ld be present on a more realistic task. A second concern was whether r
easoning with salient or emotional material would increase the hastine
ss bias in people with delusions. Two versions of a probabilistic reas
oning task were used to study the data gathering of people with delusi
ons. The first version employed realistic but emotionally neutral mate
rial. People with delusions requested less evidence before making a de
cision than psychiatric and normal comparison groups. Therefore, the h
astiness found previously with abstract materials was seen to generali
ze to a more realistic task. In the second version participants were r
equired to reason with material that had an emotional content and may
have been regarded as being personally meaningful. In this condition a
ll groups reduced the amount of evidence requested before making a dec
ision.