Facial behaviour and first impressions in computer mediated communication

Online video social interaction is now commonplace following rapid technological advances and the Covid-19 pandemic. Whether computer mediated communication (CMC) fundamentally changes nonverbal behaviour and social responses from others is unknown. Here, we conducted a repeated measures experimental study (N = 66) comparing three types of dyadic social interactions: in person, online video call (with self-view) and online video call (no self-view). Facial videos were analysed using automated facial movement tracking (based on the Facial Action Coding System: FACS). Independent raters made first impression judgements across all conditions (N = 198). Overall, people were more facially expressive in person compared to CMC, but there were significant individual differences across participants. Agreeableness was associated with a particular increase in expressivity in person compared to online, while extroversion was associated with greater expressivity in online video calls, but only when self-view was visible. Older adults were most impacted by CMC and showed the greatest reduction in facial expressivity online compared to in person. The first impressions of observers did not differ as a function of CMC. These results suggest that CMC does alter facial expressivity during social interaction, but that there is an important interplay with individual differences.