The challenges of ecological validity in the measurement of social perception in schizophrenia.

Ecological validity may be substantiated by verisimilitude (the stimuli and cognitive processing of a test resemble the stimuli and cognitive processing required in everyday life) and/or veridicality (a test is statistically associated with everyday life functioning). The Interpersonal Perception Task uses real-life social behavior as stimuli and has high verisimilitude. We examined the Interpersonal Perception Task-15 in 72 persons with schizophrenia and 58 healthy controls. The test discriminated well between groups, but failed to show associations with community functioning in participants with schizophrenia, indicating poor veridicality. This study shows that the 2 approaches to ecological validity can dissociate. Hence, it is important for investigators to conduct psychometric investigations when borrowing measures from social psychology for schizophrenia research.