Paranoid ideation and assessments of trust

The ability to make accurate social judgements is crucial to effective functioning in society. Individuals suffering from paranoia are suspicious and mistrustful of others and consequently may have difficulties accurately assessing information about others within their environment. We investigated the effects of paranoid ideation on evaluations of trustworthiness from unfamiliar faces in a non-clinical sample. Measures of paranoid beliefs about others were used to assess 122 typically developing young adults. Individuals categorised with high paranoid ideation (n = 25) and low paranoid ideation (n = 23) subsequently rated unfamiliar faces that had previously been manipulated to look untrustworthy, of average trust, and trustworthy. Individuals high in paranoid ideation rated faces as significantly less trustworthy than those low in paranoid ideation. Both groups altered their ratings according to the trustworthiness of the face, but those high in paranoia rated all faces as less trustworthy. The findings suggest a bias in social judgements in individuals with high levels of paranoid ideation. They are able to judge faces for trustworthiness but have a bias towards a lower estimation of trust.