Can social attitudes shape the ability to discriminate social signals from faces? A study on a typical developing population

The ability to discriminate social signals from faces is a fundamental component of human social interactions. Recent studies shed light on the cognitive and neural mechanisms that underlie this ability (e.g., Falvello et al., 2015). Still, there have not been many attempts to show whether it might be shaped by individual differences in social attitudes. In this study, 40 healthy participants (mean age: 25) were asked to fill in the Big Five Questionnaire (BFQ) to assess their score in extraversion. Participants were then asked to perform a discrimination task implemented with Mousetracker and interfaced with MATLAB, where they had to observe a target-face at the bottom of the screen and move the cursor towards one of the two response-face judged to be more similar to the target. The stimuli consisted of 7 computer-generated faces selected from the Todorov Inventory and which were conceived to reflect a continuum of trustworthiness from -3STD (very untrustworthy) to +3STD (very trustworthy). Participants who scored high in extraversion were found to be significantly faster in successfully assessing the task when compared to participants who scored low in extraversion. Results suggest that social attitude can modulate the ability to discriminate social traits from faces, making extrovert and thus socially more active people more expert in the evaluation of the level of trustworthiness attributable to a stranger. In contrast, reduced social interest due to introversion might constrain facial experience leading to inefficient recognition of social signals from faces.