Abstract
The dysfunctional cognitive and reasoning biases which underpin
psychotic symptoms are likely to present prior to the onset of a diagnosable
disorder and should therefore be detectable along the psychosis continuum in
individuals with schizotypal traits. Two reasoning biases, Bias Against
Disconfirmatory Evidence (BADE) and Jumping to Conclusions (JTC), describe
how information is selected and weighed under conditions of uncertainty
during decision making. It is likely that states such as elevated stress
exacerbates JTC and BADE in individuals with high schizotypal traits
vulnerable to displaying these information gathering styles. Therefore, we
evaluated whether stress and schizotypy interacted to predict these
reasoning biases using separate samples from the US (JTC) and England
(BADE). Generally speaking, schizotypal traits and stress were not
independently associated with dysfunctional reasoning biases. However,
across both studies, the interaction between schizotypy traits and stress
significantly predicted reasoning biases such that increased stress was
associated with increased reasoning biases, but only for individuals low in
schizotypal traits. These patterns were observed for positive schizotypal
traits (in both samples), for negative traits (in the England sample only),
but not for disorganization traits. For both samples, our findings suggest
that the presence of states such as stress is associated with, though not
necessarily dysfunctional, reasoning biases in individuals with low
schizotypy. These reasoning biases seemed, in some ways, relatively
immutable to stress in individuals endorsing high levels of positive
schizotypal traits.
Stress and cognitive biases in schizotypy: A two-site study of bias
against disconfirmatory evidence and jumping to conclusions