Interpretation and judgmental biases in social phobia.

Previous research demonstrated that social phobia is characterized by content-specific interpretation and judgmental biases. The present study investigated whether this interpretation bias occurs not only in ambiguous, but also in positive and negative social events, and whether social phobic patients (SPs) are more characterized by a judgmental bias in costs than in probability. Besides, we argued that the judgmental bias observed in former studies could also be attributed to accurate estimations of SPs (of, for example, stuttering). Therefore, we assessed judgmental bias by the ratings of probability and costs of a negative evaluation (e.g. 'people dislike me') and not, as in previous studies, of negative social events (e.g. 'stuttering'). SPs (n=228) and normal controls (n=33) were presented social and non-social events ranging from positive to profoundly negative. They ranked four different interpretations on likelihood to assess interpretation bias, and rated the profoundly negative interpretation on probability and cost to assess judgmental bias. SPs demonstrated content-specific interpretation and judgmental biases that also occurred in positive and negative social events. In contrast with expectations, SPs were characterized by a judgmental bias in both costs and probability.