Face first impression of trustworthiness in Williams Syndrome: Dissociating automatic vs decision based perception

Humans make rapid decisions of trustworthiness based on facial appearance. Williams Syndrome (WS) is a genetic disorder associated with hypersociability toward strangers, suggesting a disruption in trust assessment. We recorded eye-movements in neurotypically-developed (TD) participants (N = 21) and in patients with WS (N = 22) as we presented pairs of computer-generated faces, pre-rated as trustworthy or untrustworthy. In a spontaneous visual preference task, TD participants gazed significantly longer at trustworthy faces while patients with WS showed no preferences for either face-type. Next, in a decision task, participants selected the face that they judged consistent with one of three social descriptions relating to high levels of trust. Both groups gazed longer at trustworthy faces and made correct matches with the corresponding social descriptions. Improvements by patients with WS in the decision task were contingent on outcomes measured on the emotional NEPSY scale. We conclude that while spontaneous representation of trustworthiness is impaired in WS, top-down mechanisms of trust recognition appear partially preserved.